Gideon Israel Dsouza [Mon, 7 Apr 2014 22:39:20 +0000 (15:39 -0700)]
kernel: use macros from compiler.h instead of __attribute__((...))
To increase compiler portability there is <linux/compiler.h> which
provides convenience macros for various gcc constructs. Eg: __weak for
__attribute__((weak)). I've replaced all instances of gcc attributes
with the right macro in the kernel subsystem.
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Uwe Kleine-König [Mon, 7 Apr 2014 22:39:19 +0000 (15:39 -0700)]
Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP
If the renamed symbol is defined lib/iomap.c implements ioport_map and
ioport_unmap and currently (nearly) all platforms define the port
accessor functions outb/inb and friend unconditionally. So
HAS_IOPORT_MAP is the better name for this.
Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.
The motivation for this change is to reintroduce a symbol HAS_IOPORT
that signals if outb/int et al are available. I will address that at
least one merge window later though to keep surprises to a minimum and
catch new introductions of (HAS|NO)_IOPORT.
The changes in this commit were done using:
$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Mon, 7 Apr 2014 22:39:18 +0000 (15:39 -0700)]
ipc: use device_initcall
... since __initcall is now deprecated.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Mon, 7 Apr 2014 22:39:17 +0000 (15:39 -0700)]
ipc/compat.c: remove sc_semopm macro
This macro appears to have been introduced back in the 2.5 era for
semtimedop32 backward compatibility on ia32:
https://lkml.org/lkml/2003/4/28/78
Nowadays, this syscall in compat just defaults back to the code found in
sem.c, so it is no longer used and can thus be removed:
long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
unsigned nsops, const struct compat_timespec __user *timeout)
{
struct timespec __user *ts64;
if (compat_convert_timespec(&ts64, timeout))
return -EFAULT;
return sys_semtimedop(semid, tsems, nsops, ts64);
}
Furthermore, there are no users in compat.c. After this change, kernel
builds just fine with both CONFIG_SYSVIPC_COMPAT and CONFIG_SYSVIPC.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel M. Weeks [Mon, 7 Apr 2014 22:39:16 +0000 (15:39 -0700)]
initramfs: debug detected compression method
This can greatly aid in narrowing down the real source of initramfs
problems such as failures related to the compression of the in-kernel
initramfs when an external initramfs is in use as well. Existing errors
are ambiguous as to which initramfs is a problem and why.
[akpm@linux-foundation.org: use pr_debug()]
Signed-off-by: Daniel M. Weeks <dan@danweeks.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Jones [Mon, 7 Apr 2014 22:39:15 +0000 (15:39 -0700)]
fault-injection: set bounds on what /proc/self/make-it-fail accepts.
/proc/self/make-it-fail is a boolean, but accepts any number, including
negative ones. Change variable to unsigned, and cap upper bound at 1.
[akpm@linux-foundation.org: don't make make_it_fail unsigned]
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:14 +0000 (15:39 -0700)]
x86: always define BUG() and HAVE_ARCH_BUG, even with !CONFIG_BUG
This ensures that BUG() always has a definition that causes a trap (via
an undefined instruction), and that the compiler still recognizes the
code following BUG() as unreachable, avoiding warnings that would
otherwise appear (such as on non-void functions that don't return a
value after BUG()).
In addition to saving a few bytes over the generic infinite-loop
implementation, this implementation traps rather than looping, which
potentially allows for better error-recovery behavior (such as by
rebooting).
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:13 +0000 (15:39 -0700)]
bug: Make BUG() always stop the machine
When !CONFIG_BUG and !HAVE_ARCH_BUG, define the generic BUG() as an
infinite loop rather than a no-op. This avoids undefined behavior if
execution ever actually reaches BUG(), and avoids warnings about code
after BUG() (such as on non-void functions calling BUG() and then not
returning).
bloat-o-meter results:
add/remove: 0/0 grow/shrink: 43/10 up/down: 235/-98 (137)
function old new delta
umount_collect 119 138 +19
notify_change 306 324 +18
xstate_enable_boot_cpu 252 269 +17
kunmap 54 70 +16
balloon_page_dequeue 112 126 +14
mm_take_all_locks 223 233 +10
list_lru_walk_node 143 152 +9
vma_adjust 1059 1067 +8
pcpu_setup_first_chunk 1130 1138 +8
mm_drop_all_locks 143 151 +8
ns_capable 55 62 +7
anon_transport_class_unregister 8 15 +7
srcu_init_notifier_head 35 41 +6
shrink_dcache_for_umount 174 180 +6
kunmap_high 99 105 +6
end_page_writeback 43 49 +6
do_exit 1339 1345 +6
__kfifo_dma_out_prepare_r 86 92 +6
__kfifo_dma_in_prepare_r 90 96 +6
fixup_user_fault 120 125 +5
repair_env_string 73 77 +4
read_cache_pages_invalidate_page 56 60 +4
isolate_lru_pages.isra 142 146 +4
do_notify_parent_cldstop 255 259 +4
cpu_init 370 374 +4
utimes_common 270 272 +2
tasklet_hi_action 91 93 +2
tasklet_action 91 93 +2
set_pte_vaddr 46 48 +2
find_get_pages_tag 202 204 +2
early_iounmap 185 187 +2
__native_set_fixmap 36 38 +2
__get_user_pages 822 824 +2
__early_ioremap 299 301 +2
yield_task_stop 1 2 +1
tick_resume 37 38 +1
switched_to_stop 1 2 +1
switched_to_idle 1 2 +1
prio_changed_stop 1 2 +1
prio_changed_idle 1 2 +1
pm_qos_power_read 111 112 +1
arch_cpu_idle_dead 1 2 +1
__insert_vmap_area 140 141 +1
sys_renameat 614 612 -2
mm_fault_error 297 295 -2
SyS_renameat 614 612 -2
sys_linkat 416 413 -3
SyS_linkat 416 413 -3
chmod_common 129 122 -7
proc_cap_handler 240 225 -15
__schedule 849 831 -18
sys_madvise 1077 1054 -23
SyS_madvise 1077 1054 -23
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:12 +0000 (15:39 -0700)]
bug: when !CONFIG_BUG, make WARN call no_printk to check format and args
The stub version of WARN for !CONFIG_BUG completely ignored its format
string and subsequent arguments; make it check them instead, using
no_printk.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:11 +0000 (15:39 -0700)]
include/asm-generic/bug.h: style fix: s/while(0)/while (0)/
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:10 +0000 (15:39 -0700)]
bug: when !CONFIG_BUG, simplify WARN_ON_ONCE and family
When !CONFIG_BUG, WARN_ON and family become simple passthroughs of their
condition argument; however, WARN_ON_ONCE and family still have conditions
and a boolean to detect one-time invocation, even though the warning
they'd emit doesn't exist. Make the existing definitions conditional on
CONFIG_BUG, and add definitions for !CONFIG_BUG that map to the
passthrough versions of WARN and WARN_ON.
This saves 4.4k on a minimized configuration (smaller than allnoconfig),
and 20.6k with defconfig plus CONFIG_BUG=n.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:09 +0000 (15:39 -0700)]
kconfig: make allnoconfig disable options behind EMBEDDED and EXPERT
"make allnoconfig" exists to ease testing of minimal configurations.
Documentation/SubmitChecklist includes a note to test with allnoconfig.
This helps catch missing dependencies on common-but-not-required
functionality, which might otherwise go unnoticed.
However, allnoconfig still leaves many symbols enabled, because they're
hidden behind CONFIG_EMBEDDED or CONFIG_EXPERT. For instance, allnoconfig
still has CONFIG_PRINTK and CONFIG_BLOCK enabled, so drivers don't
typically get build-tested with those disabled.
To address this, introduce a new Kconfig option "allnoconfig_y", used on
symbols which only exist to hide other symbols. Set it on CONFIG_EMBEDDED
(which then selects CONFIG_EXPERT). allnoconfig will then disable all the
symbols hidden behind those.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:08 +0000 (15:39 -0700)]
ppc: make PPC_BOOK3S_64 select IRQ_WORK
Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".
arch/powerpc/kernel/mce.c, compiled in for PPC_BOOK3S_64, calls
functions only built when IRQ_WORK, so select it. Fixes the following
build error:
arch/powerpc/kernel/built-in.o: In function `.machine_check_queue_event':
(.text+0x11260): undefined reference to `.irq_work_queue'
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:07 +0000 (15:39 -0700)]
ia64: select CONFIG_TTY for use of tty_write_message in unaligned
Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".
arch/ia64/kernel/unaligned.c uses tty_write_message to print an
unaligned access exception to the TTY of the current user process.
Enable TTY to prevent a build error.
Minimal fix, on the basis that few people on ia64 will care deeply about
kernel size enough to turn off TTY. Ideally, I'd instead suggest
dropping the tty_write_message entirely, and just leaving the printk.
Bonus: no need to sprintf first.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Geert Uytterhoeven [Mon, 7 Apr 2014 22:39:06 +0000 (15:39 -0700)]
cris: cpuinfo_op should depend on CONFIG_PROC_FS
Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".
Now allnoconfig started disabling CONFIG_PROC_FS:
arch/cris/kernel/built-in.o:(.rodata+0xc): undefined reference to `show_cpuinfo'
make: *** [vmlinux] Error 1
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Mon, 7 Apr 2014 22:39:04 +0000 (15:39 -0700)]
cris: make ETRAX_ARCH_V10 select TTY for use in debugport
Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".
arch/cris/arch-v10/kernel/debugport.c, compiled in unconditionally with
ETRAX_ARCH_V10, requires TTY, so select TTY to avoid a build failure.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Carpenter [Mon, 7 Apr 2014 22:39:03 +0000 (15:39 -0700)]
drivers/misc/sgi-gru/grukdump.c: cleanup gru_dump_context() a little
"ret" is zero here so we can remove the "!ret" part of the condition.
"uhdr" is alread a __user pointer so we can remove the cast.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:39:03 +0000 (15:39 -0700)]
kernel/panic.c: display reason at end + pr_emerg
Currently, booting without initrd specified on 80x25 screen gives a call
trace followed by atkbd : Spurious ACK. Original message ("VFS: Unable
to mount root fs") is not available. Of course this could happen in
other situations...
This patch displays panic reason after call trace which could help lot
of people even if it's not the very last line on screen.
Also, convert all panic.c printk(KERN_EMERG to pr_emerg(
[akpm@linux-foundation.org: missed a couple of pr_ conversions]
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:39:02 +0000 (15:39 -0700)]
fs/bfs/inode.c: add __init to init_inodecache()
init_inodecache is only called by __init init_bfs_fs
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:39:01 +0000 (15:39 -0700)]
affs: add mount option to avoid filename truncates
Normal behavior for filenames exceeding specific filesystem limits is to
refuse operation.
AFFS standard name length being only 30 characters against 255 for usual
Linux filesystems, original implementation does filename truncate by
default with a define value AFFS_NO_TRUNCATE which can be enabled but
needs module compilation.
This patch adds 'nofilenametruncate' mount option so that user can
easily activate that feature and avoid a lot of problems (eg overwrite
files ...)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:39:00 +0000 (15:39 -0700)]
fs/affs/dir.c: unlock/brelse dir on failure + code clean-up
Commit
0edf977d2ae3 ("[readdir] convert affs") returns directly -EIO
without unlocking dir inode and releasing dir bh when second affs_bread
sequence fails. This patch restores initial behaviour. It also fixes
pr_debug and affs_error to fit in 80 columns + removes reference to
filldir (replaced by dir_emit in the commit above).
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:38:59 +0000 (15:38 -0700)]
affs: add __init to init_inodecache ()
init_inodecache is only called by __init init_affs_fs
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:38:58 +0000 (15:38 -0700)]
fs/adfs/super.c: add __init to init_inodecache()
init_inodecache is only called by __init init_adfs_fs.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Liu Hua [Mon, 7 Apr 2014 22:38:57 +0000 (15:38 -0700)]
hung_task: check the value of "sysctl_hung_task_timeout_sec"
As sysctl_hung_task_timeout_sec is unsigned long, when this value is
larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in
watchdog will return immediately without sleep and with print :
schedule_timeout: wrong timeout value
ffffffffffffff83
and then the funtion watchdog will call schedule_timeout_interruptible
again and again. The screen will be filled with
"schedule_timeout: wrong timeout value
ffffffffffffff83"
This patch does some check and correction in sysctl, to let the function
schedule_timeout_interruptible allways get the valid parameter.
Signed-off-by: Liu Hua <sdu.liu@huawei.com>
Tested-by: Satoru Takeuchi <satoru.takeuchi@gmail.com>
Cc: <stable@vger.kernel.org> [3.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexandre Bounine [Mon, 7 Apr 2014 22:38:56 +0000 (15:38 -0700)]
rapidio: rework device hierarchy and introduce mport class of devices
This patch removes an artificial RapidIO bus root device and establishes
actual device hierarchy by providing reference to real parent devices.
It also introduces device class for RapidIO controller devices (on-chip
or an eternal bridge, known as "mport").
Existing implementation was sufficient for SoC-based platforms that have
a single RapidIO controller. With introduction of devices using
multiple RapidIO controllers and PCIe-to-RapidIO bridges the old scheme
is very limiting or does not work at all. The implemented changes allow
to properly reference platform's local RapidIO mport devices and provide
device details needed for upper layers.
This change to RapidIO device hierarchy does not break any known
existing kernel or user space interfaces.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
Cc: Jerry Jacobs <jerry.jacobs@prodrive-technologies.com>
Cc: Arno Tiemersma <arno.tiemersma@prodrive-technologies.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexandre Bounine [Mon, 7 Apr 2014 22:38:55 +0000 (15:38 -0700)]
drivers/rapidio/devices/tsi721_dma.c: optimize use of BDMA descriptors
Combine SG entries describing single contiguous memory block into one
Tsi721 BDMA descriptor. This reduces number of hardware descriptors
required for large data transfers and improves performance on the PCIe
side by reducing number of descriptor fetch requests.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Monam Agarwal [Mon, 7 Apr 2014 22:38:54 +0000 (15:38 -0700)]
lib/idr.c: use RCU_INIT_POINTER(x, NULL)
Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL)
The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure. And in the
case of the NULL pointer, there is no structure to initialize.
So, rcu_assign_pointer(p, NULL) can be safely converted to
RCU_INIT_POINTER(p, NULL)
Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stephen Hemminger [Mon, 7 Apr 2014 22:38:52 +0000 (15:38 -0700)]
idr: remove dead code
Remove no longer used deprecated code, and make local functions
static.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: George Spelvin <linux@horizon.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WANG Chao [Mon, 7 Apr 2014 22:38:51 +0000 (15:38 -0700)]
vmcore: continue vmcore initialization if PT_NOTE is found empty
Currently when an empty PT_NOTE is detected, vmcore initialization
fails. It sounds too harsh. Because PT_NOTE could be empty, for
example, one offlined a cpu but never restarted kdump service, and after
crash, PT_NOTE program header is there but no data contains. It's
better to warn about the empty PT_NOTE and continue to initialise
vmcore.
And ultimately the multiple PT_NOTE are merged into a single one, all
empty PT_NOTE are discarded naturally during the merge. So empty
PT_NOTE is not visible to user space and vmcore is as good as expected.
Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Greg Pearson <greg.pearson@hp.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rashika Kheria [Mon, 7 Apr 2014 22:38:50 +0000 (15:38 -0700)]
include/linux/crash_dump.h: add vmcore_cleanup() prototype
Eliminate the following warning in proc/vmcore.c:
fs/proc/vmcore.c:1088:6: warning: no previous prototype for `vmcore_cleanup' [-Wmissing-prototypes]
[akpm@linux-foundation.org: clean up powerpc, remove unneeded EXPORT_SYMBOL]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:49 +0000 (15:38 -0700)]
wait: WSTOPPED|WCONTINUED doesn't work if a zombie leader is traced by another process
Even if the main thread is dead the process still can stop/continue.
However, if the leader is ptraced wait_consider_task(ptrace => false)
always skips wait_task_stopped/wait_task_continued, so WSTOPPED or
WCONTINUED can never work for the natural parent in this case.
Move the "A zombie ptracee is only visible to its ptracer" check into the
"if (!delay_group_leader(p))" block. ->notask_error is cleared by the
"fall through" code below.
This depends on the previous change, wait_task_stopped/continued must be
avoided if !delay_group_leader() and the tracer is ->real_parent.
Otherwise WSTOPPED|WEXITED could wrongly report "stopped" when the child
is already dead (single-threaded or not). If it is traced by another task
then the "stopped" state is fine until the debugger detaches and reveals a
zombie state.
Stupid test-case:
void *tfunc(void *arg)
{
sleep(1); // wait for zombie leader
raise(SIGSTOP);
exit(0x13);
return NULL;
}
int run_child(void)
{
pthread_t thread;
if (!fork()) {
int tracee = getppid();
assert(ptrace(PTRACE_ATTACH, tracee, 0,0) == 0);
do
ptrace(PTRACE_CONT, tracee, 0,0);
while (wait(NULL) > 0);
return 0;
}
sleep(1); // wait for PTRACE_ATTACH
assert(pthread_create(&thread, NULL, tfunc, NULL) == 0);
pthread_exit(NULL);
}
int main(void)
{
int child, stat;
child = fork();
if (!child)
return run_child();
assert(child == waitpid(-1, &stat, WSTOPPED));
assert(stat == 0x137f);
kill(child, SIGCONT);
assert(child == waitpid(-1, &stat, WCONTINUED));
assert(stat == 0xffff);
assert(child == waitpid(-1, &stat, 0));
assert(stat == 0x1300);
return 0;
}
Without this patch it hangs in waitpid(WSTOPPED), wait_task_stopped() is
never called.
Note: this doesn't fix all problems with a zombie delay_group_leader(),
WCONTINUED | WEXITED check is not exactly right. debugger can't assume it
will be notified if another thread reaps the whole thread group.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:47 +0000 (15:38 -0700)]
wait: WSTOPPED|WCONTINUED hangs if a zombie child is traced by real_parent
"A zombie is only visible to its ptracer" logic in wait_consider_task()
is very wrong. Trivial test-case:
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <assert.h>
int main(void)
{
int child = fork();
if (!child) {
assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);
return 0x23;
}
assert(waitid(P_ALL, child, NULL, WEXITED | WNOWAIT) == 0);
assert(waitid(P_ALL, 0, NULL, WSTOPPED) == -1);
return 0;
}
it hangs in waitpid(WSTOPPED) despite the fact it has a single zombie
child. This is because wait_consider_task(ptrace => 0) sees p->ptrace and
cleares ->notask_error assuming that the debugger should detach and notify
us.
Change wait_consider_task(ptrace => 0) to pretend that ptrace == T if the
child is traced by us. This really simplifies the logic and allows us to
do more fixes, see the next changes. This also hides the unwanted group
stop state automatically, we can remove another ptrace_reparented() check.
Unfortunately, this adds the following behavioural changes:
1. Before this patch wait(WEXITED | __WNOTHREAD) does not reap
a natural child if it is traced by the caller's sub-thread.
Hopefully nobody will ever notice this change, and I think
that nobody should rely on this behaviour anyway.
2. SIGNAL_STOP_CONTINUED is no longer hidden from debugger if
it is real parent.
While this change comes as a side effect, I think it is good
by itself. The group continued state can not be consumed by
another process in this case, it doesn't depend on ptrace,
it doesn't make sense to hide it from real parent.
Perhaps we should add the thread_group_leader() check before
wait_task_continued()? May be, but this shouldn't depend on
ptrace_reparented().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:46 +0000 (15:38 -0700)]
wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide EXIT_TRACE from user-space
get_task_state() uses the most significant bit to report the state to
user-space, this means that EXIT_ZOMBIE->EXIT_TRACE->EXIT_DEAD transition
can be noticed via /proc as Z -> X -> Z change. Note that this was
possible even before EXIT_TRACE was introduced.
This is not really bad but imho it make sense to hide EXIT_TRACE from
user-space completely. So the patch simply swaps EXIT_ZOMBIE and
EXIT_DEAD, this way EXIT_TRACE will be seen as EXIT_ZOMBIE by user-space.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:45 +0000 (15:38 -0700)]
wait: completely ignore the EXIT_DEAD tasks
Now that EXIT_DEAD is the terminal state it doesn't make sense to call
eligible_child() or security_task_wait() if the task is really dead.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Michal Schmidt <mschmidt@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:43 +0000 (15:38 -0700)]
wait: use EXIT_TRACE only if thread_group_leader(zombie)
wait_task_zombie() always uses EXIT_TRACE/ptrace_unlink() if
ptrace_reparented(). This is suboptimal and a bit confusing: we do not
need do_notify_parent(p) if !thread_group_leader(p) and in this case we
also do not need ptrace_unlink(), we can rely on ptrace_release_task().
Change wait_task_zombie() to check thread_group_leader() along with
ptrace_reparented() and simplify the final p->exit_state transition.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Michal Schmidt <mschmidt@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:42 +0000 (15:38 -0700)]
wait: introduce EXIT_TRACE to avoid the racy EXIT_DEAD->EXIT_ZOMBIE transition
wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and
drops tasklist_lock. If this task is not the natural child and it is
traced, we change its state back to EXIT_ZOMBIE for ->real_parent.
The last transition is racy, this is even documented in
50b8d257486a
"ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE
race". wait_consider_task() tries to detect this transition and clear
->notask_error but we can't rely on ptrace_reparented(), debugger can
exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE.
And there is another problem which were missed before: this transition
can also race with reparent_leader() which doesn't reset >exit_signal if
EXIT_DEAD, assuming that this task must be reaped by someone else. So
the tracee can be re-parented with ->exit_signal != SIGCHLD, and if
/sbin/init doesn't use __WALL it becomes unreapable. This was fixed by
the previous commit, but it was the temporary hack.
1. Add the new exit_state, EXIT_TRACE. It means that the task is the
traced zombie, debugger is going to detach and notify its natural
parent.
This new state is actually EXIT_ZOMBIE | EXIT_DEAD. This way we
can avoid the changes in proc/kgdb code, get_task_state() still
reports "X (dead)" in this case.
Note: with or without this change userspace can see Z -> X -> Z
transition. Not really bad, but probably makes sense to fix.
2. Change wait_task_zombie() to use EXIT_TRACE instead of EXIT_DEAD
if we need to notify the ->real_parent.
3. Revert the previous hack in reparent_leader(), now that EXIT_DEAD
is always the final state we can safely ignore such a task.
4. Change wait_consider_task() to check EXIT_TRACE separately and kill
the racy and no longer needed ptrace_reparented() case.
If ptrace == T an EXIT_TRACE thread should be simply ignored, the
owner of this state is going to ptrace_unlink() this task. We can
pretend that it was already removed from ->ptraced list.
Otherwise we should skip this thread too but clear ->notask_error,
we must be the natural parent and debugger is going to untrace and
notify us. IOW, this doesn't differ from "EXIT_ZOMBIE && p->ptrace"
even if the task was already untraced.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Reported-by: Michal Schmidt <mschmidt@redhat.com>
Tested-by: Michal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:41 +0000 (15:38 -0700)]
wait: fix reparent_leader() vs EXIT_DEAD->EXIT_ZOMBIE race
wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and
drops tasklist_lock. If this task is not the natural child and it is
traced, we change its state back to EXIT_ZOMBIE for ->real_parent.
The last transition is racy, this is even documented in
50b8d257486a
"ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE
race". wait_consider_task() tries to detect this transition and clear
->notask_error but we can't rely on ptrace_reparented(), debugger can
exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE.
And there is another problem which were missed before: this transition
can also race with reparent_leader() which doesn't reset >exit_signal if
EXIT_DEAD, assuming that this task must be reaped by someone else. So
the tracee can be re-parented with ->exit_signal != SIGCHLD, and if
/sbin/init doesn't use __WALL it becomes unreapable.
Change reparent_leader() to update ->exit_signal even if EXIT_DEAD.
Note: this is the simple temporary hack for -stable, it doesn't try to
solve all problems, it will be reverted by the next changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Reported-by: Michal Schmidt <mschmidt@redhat.com>
Tested-by: Michal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:39 +0000 (15:38 -0700)]
exec: kill bprm->tcomm[], simplify the "basename" logic
Starting from commit
c4ad8f98bef7 ("execve: use 'struct filename *' for
executable name passing") bprm->filename can not go away after
flush_old_exec(), so we do not need to save the binary name in
bprm->tcomm[] added by
96e02d158678 ("exec: fix use-after-free bug in
setup_new_exec()").
And there was never need for filename_to_taskname-like code, we can
simply do set_task_comm(kbasename(filename).
This patch has to change set_task_comm() and trace_task_rename() to
accept "const char *", but I think this change is also good.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Djalal Harouni [Mon, 7 Apr 2014 22:38:38 +0000 (15:38 -0700)]
procfs: make /proc/*/pagemap 0400
The /proc/*/pagemap contain sensitive information and currently its mode
is 0444. Change this to 0400, so the VFS will prevent unprivileged
processes from getting file descriptors on arbitrary privileged
/proc/*/pagemap files.
This reduces the scope of address space leaking and bypasses by protecting
already running processes.
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Djalal Harouni [Mon, 7 Apr 2014 22:38:36 +0000 (15:38 -0700)]
procfs: make /proc/*/{stack,syscall,personality} 0400
These procfs files contain sensitive information and currently their
mode is 0444. Change this to 0400, so the VFS will be able to block
unprivileged processes from getting file descriptors on arbitrary
privileged /proc/*/{stack,syscall,personality} files.
This reduces the scope of ASLR leaking and bypasses by protecting already
running processes.
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Monam Agarwal [Mon, 7 Apr 2014 22:38:35 +0000 (15:38 -0700)]
fs/proc/inode.c: use RCU_INIT_POINTER(x, NULL)
Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL)
The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure. And in the
case of the NULL pointer, there is no structure to initialize. So,
rcu_assign_pointer(p, NULL) can be safely converted to
RCU_INIT_POINTER(p, NULL)
Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Vagin [Mon, 7 Apr 2014 22:38:34 +0000 (15:38 -0700)]
proc: show mnt_id in /proc/pid/fdinfo
Currently we don't have a way how to determing from which mount point
file has been opened. This information is required for proper dumping
and restoring file descriptos due to presence of mount namespaces. It's
possible, that two file descriptors are opened using the same paths, but
one fd references mount point from one namespace while the other fd --
from other namespace.
$ ls -l /proc/1/fd/1
lrwx------ 1 root root 64 Mar 19 23:54 /proc/1/fd/1 -> /dev/null
$ cat /proc/1/fdinfo/1
pos: 0
flags:
0100002
mnt_id: 16
$ cat /proc/1/mountinfo | grep ^16
16 32 0:4 / /dev rw,nosuid shared:2 - devtmpfs devtmpfs rw,size=1013356k,nr_inodes=253339,mode=755
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Rob Landley <rob@landley.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Luiz Capitulino [Mon, 7 Apr 2014 22:38:32 +0000 (15:38 -0700)]
fs/proc/meminfo: meminfo_proc_show(): fix typo in comment
It should read "reclaimable slab" and not "reclaimable swap".
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guillaume Morin [Mon, 7 Apr 2014 22:38:31 +0000 (15:38 -0700)]
kernel/exit.c: call proc_exit_connector() after exit_state is set
The process events connector delivers a notification when a process
exits. This is really convenient for a process that spawns and wants to
monitor its children through an epoll-able() interface.
Unfortunately, there is a small window between when the event is
delivered and the child become wait()-able.
This is creates a race if the parent wants to make sure that it knows
about the exit, e.g
pid_t pid = fork();
if (pid > 0) {
register_interest_for_pid(pid);
if (waitpid(pid, NULL, WNOHANG) > 0)
{
/* We might have raced with exit() */
}
return;
}
/* Child */
execve(...)
register_interest_for_pid() would be telling the the connector socket
reader to pay attention to events related to pid.
Though this is not a bug, I think it would make the connector a bit more
usable if this race was closed by simply moving the call to
proc_exit_connector() from just before exit_notify() to right after.
Oleg said:
: Even with this patch the code above is still "racy" if the child is
: multi-threaded. Plus it should obviously filter-out subthreads. And
: afaics there is no way to make it reliable, even if you change the code
: above so that waitpid() is called only after the last thread exits WNOHANG
: still can fail.
Signed-off-by: Guillaume Morin <guillaume@morinfr.org>
Cc: Matt Helsley <matt.helsley@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:30 +0000 (15:38 -0700)]
exit: move check_stack_usage() to the end of do_exit()
It is not clear why check_stack_usage() is called so early and thus it
never checks the stack usage in, say, exit_notify() or
flush_ptrace_hw_breakpoint() or other functions which are only called by
do_exit().
Move the callsite down to the last preempt_disable/schedule.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Mon, 7 Apr 2014 22:38:29 +0000 (15:38 -0700)]
exit: call disassociate_ctty() before exit_task_namespaces()
Commit
8aac62706ada ("move exit_task_namespaces() outside of
exit_notify()") breaks pppd and the exiting service crashes the kernel:
BUG: unable to handle kernel NULL pointer dereference at
0000000000000028
IP: ppp_register_channel+0x13/0x20 [ppp_generic]
Call Trace:
ppp_asynctty_open+0x12b/0x170 [ppp_async]
tty_ldisc_open.isra.2+0x27/0x60
tty_ldisc_hangup+0x1e3/0x220
__tty_hangup+0x2c4/0x440
disassociate_ctty+0x61/0x270
do_exit+0x7f2/0xa50
ppp_register_channel() needs ->net_ns and current->nsproxy == NULL.
Move disassociate_ctty() before exit_task_namespaces(), it doesn't make
sense to delay it after perf_event_exit_task() or cgroup_exit().
This also allows to use task_work_add() inside the (nontrivial) code
paths in disassociate_ctty().
Investigated by Peter Hurley.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Sree Harsha Totakura <sreeharsha@totakura.in>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Sree Harsha Totakura <sreeharsha@totakura.in>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org> [v3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SeongJae Park [Mon, 7 Apr 2014 22:38:28 +0000 (15:38 -0700)]
mm/zswap.c: remove unnecessary parentheses
Fix following trivial checkpatch error:
ERROR: return is not a function, parentheses are not required
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Acked-by: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Mon, 7 Apr 2014 22:38:27 +0000 (15:38 -0700)]
mm/zswap: support multiple swap devices
Cai Liu reporeted that now zbud pool pages counting has a problem when
multiple swap is used because it just counts only one swap intead of all
of swap so zswap cannot control writeback properly. The result is
unnecessary writeback or no writeback when we should really writeback.
IOW, it made zswap crazy.
Another problem in zswap is:
For example, let's assume we use two swap A and B with different
priority and A already has charged 19% long time ago and let's assume
that A swap is full now so VM start to use B so that B has charged 1%
recently. It menas zswap charged (19% + 1%) is full by default. Then,
if VM want to swap out more pages into B, zbud_reclaim_page would be
evict one of pages in B's pool and it would be repeated continuously.
It's totally LRU reverse problem and swap thrashing in B would happen.
This patch makes zswap consider mutliple swap by creating *a* zbud pool
which will be shared by multiple swap so all of zswap pages in multiple
swap keep order by LRU so it can prevent above two problems.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Cai Liu <cai.liu@samsung.com>
Suggested-by: Weijie Yang <weijie.yang.kh@gmail.com>
Cc: Seth Jennings <sjennings@variantweb.net>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SeongJae Park [Mon, 7 Apr 2014 22:38:26 +0000 (15:38 -0700)]
mm/zswap.c: update zsmalloc in comment to zbud
zswap used zsmalloc before and now using zbud. But, some comments saying
it use zsmalloc yet. Fix the trivial problems.
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SeongJae Park [Mon, 7 Apr 2014 22:38:25 +0000 (15:38 -0700)]
mm/zswap.c: fix trivial typo and arrange indentation
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joonsoo Kim [Mon, 7 Apr 2014 22:38:24 +0000 (15:38 -0700)]
zram: support REQ_DISCARD
zram is ram based block device and can be used by backend of filesystem.
When filesystem deletes a file, it normally doesn't do anything on data
block of that file. It just marks on metadata of that file. This
behavior has no problem on disk based block device, but has problems on
ram based block device, since we can't free memory used for data block.
To overcome this disadvantage, there is REQ_DISCARD functionality. If
block device support REQ_DISCARD and filesystem is mounted with discard
option, filesystem sends REQ_DISCARD to block device whenever some data
blocks are discarded. All we have to do is to handle this request.
This patch implements to flag up QUEUE_FLAG_DISCARD and handle this
REQ_DISCARD request. With it, we can free memory used by zram if it isn't
used.
[akpm@linux-foundation.org: tweak comments]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:22 +0000 (15:38 -0700)]
zram: use scnprintf() in attrs show() methods
sysfs.txt documentation lists the following requirements:
- The buffer will always be PAGE_SIZE bytes in length. On i386, this
is 4096.
- show() methods should return the number of bytes printed into the
buffer. This is the return value of scnprintf().
- show() should always use scnprintf().
Use scnprintf() in show() functions.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Mon, 7 Apr 2014 22:38:21 +0000 (15:38 -0700)]
zram: propagate error to user
When we initialized zcomp with single, we couldn't change
max_comp_streams without zram reset but current interface doesn't show
any error to user and even it changes max_comp_streams's value without
any effect so it would make user very confusing.
This patch prevents max_comp_streams's change when zcomp was initialized
as single zcomp and emit the error to user(ex, echo).
[akpm@linux-foundation.org: don't return with the lock held, per Sergey]
[fengguang.wu@intel.com: fix coccinelle warnings]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:20 +0000 (15:38 -0700)]
zram: return error-valued pointer from zcomp_create()
Instead of returning just NULL, return ERR_PTR from zcomp_create() if
compressing backend creation has failed. ERR_PTR(-EINVAL) for unsupported
compression algorithm request, ERR_PTR(-ENOMEM) for allocation (zcomp or
compression stream) error.
Perform IS_ERR() check of returned from zcomp_create() value in
disksize_store() and set return code to PTR_ERR().
Change suggested by Jerome Marchand.
[akpm@linux-foundation.org: clean up error recovery flow]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:19 +0000 (15:38 -0700)]
zram: move comp allocation out of init_lock
While fixing lockdep spew of ->init_lock reported by Sasha Levin [1],
Minchan Kim noted [2] that it's better to move compression backend
allocation (using GPF_KERNEL) out of the ->init_lock lock, same way as
with zram_meta_alloc(), in order to prevent the same lockdep spew.
[1] https://lkml.org/lkml/2014/2/27/337
[2] https://lkml.org/lkml/2014/3/3/32
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:18 +0000 (15:38 -0700)]
zram: add lz4 algorithm backend
Introduce LZ4 compression backend and make it available for selection.
LZ4 support is optional and requires user to set ZRAM_LZ4_COMPRESS config
option. The default compression backend is LZO.
TEST
(x86_64, core i5, 2 cores + 2 hyperthreading, zram disk size 1G,
ext4 file system, 3 compression streams)
iozone -t 3 -R -r 16K -s 60M -I +Z
Test LZO LZ4
----------------------------------------------
Initial write
1642744.62
1317005.09
Rewrite
2498980.88
1800645.16
Read
3957026.38
5877043.75
Re-read
3950997.38
5861847.00
Reverse Read
2937114.56
5047384.00
Stride read
2948163.19
4929587.38
Random read
3292692.69
4880793.62
Mixed workload
1545602.62
3502940.38
Random write
2448039.75
1758786.25
Pwrite
1670051.03
1338329.69
Pread
2530682.00
5097177.62
Fwrite
3232085.62
3275942.56
Fread
6306880.25
6645271.12
So on my system LZ4 is slower in write-only tests, while it performs
better in read-only and mixed (reads + writes) tests.
Official LZ4 benchmarks available here http://code.google.com/p/lz4/
(linux kernel uses revision r90).
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:17 +0000 (15:38 -0700)]
zram: make compression algorithm selection possible
Add and document `comp_algorithm' device attribute. This attribute allows
to show supported compression and currently selected compression
algorithms:
cat /sys/block/zram0/comp_algorithm
[lzo] lz4
and change selected compression algorithm:
echo lzo > /sys/block/zram0/comp_algorithm
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:15 +0000 (15:38 -0700)]
zram: add set_max_streams knob
This patch allows to change max_comp_streams on initialised zcomp.
Introduce zcomp set_max_streams() knob, zcomp_strm_multi_set_max_streams()
and zcomp_strm_single_set_max_streams() callbacks to change streams limit
for zcomp_strm_multi and zcomp_strm_single, accordingly. set_max_streams
for single steam zcomp does nothing.
If user has lowered the limit, then zcomp_strm_multi_set_max_streams()
attempts to immediately free extra streams (as much as it can, depending
on idle streams availability).
Note, this patch does not allow to change stream 'policy' from single to
multi stream (or vice versa) on already initialised compression backend.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:14 +0000 (15:38 -0700)]
zram: add multi stream functionality
Existing zram (zcomp) implementation has only one compression stream
(buffer and algorithm private part), so in order to prevent data
corruption only one write (compress operation) can use this compression
stream, forcing all concurrent write operations to wait for stream lock
to be released. This patch changes zcomp to keep a compression streams
list of user-defined size (via sysfs device attr). Each write operation
still exclusively holds compression stream, the difference is that we
can have N write operations (depending on size of streams list)
executing in parallel. See TEST section later in commit message for
performance data.
Introduce struct zcomp_strm_multi and a set of functions to manage
zcomp_strm stream access. zcomp_strm_multi has a list of idle
zcomp_strm structs, spinlock to protect idle list and wait queue, making
it possible to perform parallel compressions.
The following set of functions added:
- zcomp_strm_multi_find()/zcomp_strm_multi_release()
find and release a compression stream, implement required locking
- zcomp_strm_multi_create()/zcomp_strm_multi_destroy()
create and destroy zcomp_strm_multi
zcomp ->strm_find() and ->strm_release() callbacks are set during
initialisation to zcomp_strm_multi_find()/zcomp_strm_multi_release()
correspondingly.
Each time zcomp issues a zcomp_strm_multi_find() call, the following set
of operations performed:
- spin lock strm_lock
- if idle list is not empty, remove zcomp_strm from idle list, spin
unlock and return zcomp stream pointer to caller
- if idle list is empty, current adds itself to wait queue. it will be
awaken by zcomp_strm_multi_release() caller.
zcomp_strm_multi_release():
- spin lock strm_lock
- add zcomp stream to idle list
- spin unlock, wake up sleeper
Minchan Kim reported that spinlock-based locking scheme has demonstrated
a severe perfomance regression for single compression stream case,
comparing to mutex-based (see https://lkml.org/lkml/2014/2/18/16)
base spinlock mutex
==Initial write ==Initial write ==Initial write
records: 5 records: 5 records: 5
avg:
1642424.35 avg: 699610.40 avg:
1655583.71
std: 39890.95(2.43%) std: 232014.19(33.16%) std: 52293.96
max:
1690170.94 max:
1163473.45 max:
1697164.75
min:
1568669.52 min: 573429.88 min:
1553410.23
==Rewrite ==Rewrite ==Rewrite
records: 5 records: 5 records: 5
avg:
1611775.39 avg: 501406.64 avg:
1684419.11
std: 17144.58(1.06%) std: 15354.41(3.06%) std: 18367.42
max:
1641800.95 max: 531356.78 max:
1706445.84
min:
1593515.27 min: 488817.78 min:
1655335.73
When only one compression stream available, mutex with spin on owner
tends to perform much better than frequent wait_event()/wake_up(). This
is why single stream implemented as a special case with mutex locking.
Introduce and document zram device attribute max_comp_streams. This
attr shows and stores current zcomp's max number of zcomp streams
(max_strm). Extend zcomp's zcomp_create() with `max_strm' parameter.
`max_strm' limits the number of zcomp_strm structs in compression
backend's idle list (max_comp_streams).
max_comp_streams used during initialisation as follows:
-- passing to zcomp_create() max_strm equals to 1 will initialise zcomp
using single compression stream zcomp_strm_single (mutex-based locking).
-- passing to zcomp_create() max_strm greater than 1 will initialise zcomp
using multi compression stream zcomp_strm_multi (spinlock-based locking).
default max_comp_streams value is 1, meaning that zram with single stream
will be initialised.
Later patch will introduce configuration knob to change max_comp_streams
on already initialised and used zcomp.
TEST
iozone -t 3 -R -r 16K -s 60M -I +Z
test base 1 strm (mutex) 3 strm (spinlock)
-----------------------------------------------------------------------
Initial write 589286.78 583518.39 718011.05
Rewrite 604837.97 596776.38
1515125.72
Random write 584120.11 595714.58
1388850.25
Pwrite 535731.17 541117.38 739295.27
Fwrite
1418083.88
1478612.72
1484927.06
Usage example:
set max_comp_streams to 4
echo 4 > /sys/block/zram0/max_comp_streams
show current max_comp_streams (default value is 1).
cat /sys/block/zram0/max_comp_streams
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:13 +0000 (15:38 -0700)]
zram: factor out single stream compression
This is preparation patch to add multi stream support to zcomp.
Introduce struct zcomp_strm_single and a set of functions to manage
zcomp_strm stream access. zcomp_strm_single implements single compession
stream, same way as current zcomp implementation. This moves zcomp_strm
stream control and locking from zcomp, so compressing backend zcomp is not
aware of required locking.
Single and multi streams require different locking schemes. Minchan Kim
reported that spinlock-based locking scheme (which is used in multi stream
implementation) has demonstrated a severe perfomance regression for single
compression stream case, comparing to mutex-based. see
https://lkml.org/lkml/2014/2/18/16
The following set of functions added:
- zcomp_strm_single_find()/zcomp_strm_single_release()
find and release a compression stream, implement required locking
- zcomp_strm_single_create()/zcomp_strm_single_destroy()
create and destroy zcomp_strm_single
New ->strm_find() and ->strm_release() callbacks added to zcomp, which are
set to zcomp_strm_single_find() and zcomp_strm_single_release() during
initialisation. Instead of direct locking and zcomp_strm access from
zcomp_strm_find() and zcomp_strm_release(), zcomp now calls ->strm_find()
and ->strm_release() correspondingly.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:12 +0000 (15:38 -0700)]
zram: use zcomp compressing backends
Do not perform direct LZO compress/decompress calls, initialise
and use zcomp LZO backend (single compression stream) instead.
[akpm@linux-foundation.org: resolve conflicts with zram-delete-zram_init_device-fix.patch]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:11 +0000 (15:38 -0700)]
zram: introduce compressing backend abstraction
ZRAM performs direct LZO compression algorithm calls, making it the one
and only option. While LZO is generally performs well, LZ4 algorithm
tends to have a faster decompression (see http://code.google.com/p/lz4/
for full report)
Name Ratio C.speed D.speed
MB/s MB/s
LZ4 (r101) 2.084 422 1820
LZO 2.06 2.106 414 600
Thus, users who have mostly read (decompress) usage scenarious or mixed
workflow (writes with relatively high read ops number) will benefit from
using LZ4 compression backend.
Introduce compressing backend abstraction zcomp in order to support
multiple compression algorithms with the following set of operations:
.create
.destroy
.compress
.decompress
Schematically zram write() usually contains the following steps:
0) preparation (decompression of partioal IO, etc.)
1) lock buffer_lock mutex (protects meta compress buffers)
2) compress (using meta compress buffers)
3) alloc and map zs_pool object
4) copy compressed data (from meta compress buffers) to object allocated by 3)
5) free previous pool page, assign a new one
6) unlock buffer_lock mutex
As we can see, compressing buffers must remain untouched from 1) to 4),
because, otherwise, concurrent write() can overwrite data. At the same
time, zram_meta must be aware of a) specific compression algorithm memory
requirements and b) necessary locking to protect compression buffers. To
remove requirement a) new struct zcomp_strm introduced, which contains a
compress/decompress `buffer' and compression algorithm `private' part.
While struct zcomp implements zcomp_strm stream handling and locking and
removes requirement b) from zram meta. zcomp ->create() and ->destroy(),
respectively, allocate and deallocate algorithm specific zcomp_strm
`private' part.
Every zcomp has zcomp stream and mutex to protect its compression stream.
Stream usage semantics remains the same -- only one write can hold stream
lock and use its buffers. zcomp_strm_find() turns caller into exclusive
user of a stream (holding stream mutex until zram release stream), and
zcomp_strm_release() makes zcomp stream available (unlock the stream
mutex). Hence no concurrent write (compression) operations possible at
the moment.
iozone -t 3 -R -r 16K -s 60M -I +Z
test base patched
--------------------------------------------------
Initial write 597992.91 591660.58
Rewrite 609674.34 616054.97
Read
2404771.75
2452909.12
Re-read
2459216.81
2470074.44
Reverse Read
1652769.66
1589128.66
Stride read
2202441.81
2202173.31
Random read
2236311.47
2276565.31
Mixed workload
1423760.41
1709760.06
Random write 579584.08 615933.86
Pwrite 597550.02 594933.70
Pread
1703672.53
1718126.72
Fwrite
1330497.06
1461054.00
Fread
3922851.00
3957242.62
Usage examples:
comp = zcomp_create(NAME) /* NAME e.g. "lzo" */
which initialises compressing backend if requested algorithm is supported.
Compress:
zstrm = zcomp_strm_find(comp)
zcomp_compress(comp, zstrm, src, &dst_len)
[..] /* copy compressed data */
zcomp_strm_release(comp, zstrm)
Decompress:
zcomp_decompress(comp, src, src_len, dst);
Free compessing backend and its zcomp stream:
zcomp_destroy(comp)
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:09 +0000 (15:38 -0700)]
zram: delete zram_init_device()
allocate new `zram_meta' in disksize_store() only for uninitialised zram
device, saving a number of allocations and deallocations in case if
disksize_store() was called on currently used device. at the same time
zram_meta stack variable is not necessary, because we can set ->meta
directly. there is also no need in setting QUEUE_FLAG_NONROT queue on
every disksize_store(), set it once during device creation.
[minchan@kernel.org: handle zram->meta alloc fail case]
[minchan@kernel.org: prevent lockdep spew of init_lock]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:08 +0000 (15:38 -0700)]
zram: document failed_reads, failed_writes stats
Document `failed_reads' and `failed_writes' device attributes.
Remove info about `discard' - there is no such zram attr.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:07 +0000 (15:38 -0700)]
zram: move zram size warning to documentation
Move zram warning about disksize and size of memory correlation to zram
documentation.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:06 +0000 (15:38 -0700)]
zram: drop not used table `count' member
struct table `count' member is not used.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:05 +0000 (15:38 -0700)]
zram: report failed read and write stats
zram accounted but did not report numbers of failed read and write
queries. make these stats available as failed_reads and failed_writes
attrs.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:04 +0000 (15:38 -0700)]
zram: remove zram stats code duplication
Introduce ZRAM_ATTR_RO macro that generates device_attribute and default
ATTR show() function for existing atomic64_t zram stats.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:03 +0000 (15:38 -0700)]
zram: use atomic64_t for all zram stats
This is a preparation patch for stats code duplication removal.
1) use atomic64_t for `pages_zero' and `pages_stored' zram stats.
2) `compr_size' and `pages_zero' struct zram_stats members did not
follow the existing device attr naming scheme: zram_stats.ATTR has
ATTR_show() function. rename them:
-- compr_size -> compr_data_size
-- pages_zero -> zero_pages
Minchan Kim's note:
If we really have trouble with atomic stat operation, we could
change it with percpu_counter so that it could solve atomic overhead and
unnecessary memory space by introducing unsigned long instead of 64bit
atomic_t.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:02 +0000 (15:38 -0700)]
zram: remove good and bad compress stats
Remove `good' and `bad' compressed sub-requests stats. RW request may
cause a number of RW sub-requests. zram used to account `good' compressed
sub-queries (with compressed size less than 50% of original size), `bad'
compressed sub-queries (with compressed size greater that 75% of original
size), leaving sub-requests with compression size between 50% and 75% of
original size not accounted and not reported. zram already accounts each
sub-request's compression size so we can calculate real device compression
ratio.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:01 +0000 (15:38 -0700)]
zram: do not pass rw argument to __zram_make_request()
Do not pass rw argument down the __zram_make_request() -> zram_bvec_rw()
chain, decode it in zram_bvec_rw() instead. Besides, this is the place
where we distinguish READ and WRITE bio data directions, so account zram
RW stats here, instead of __zram_make_request(). This also allows to
account a real number of zram READ/WRITE operations, not just requests
(single RW request may cause a number of zram RW ops with separate
locking, compression/decompression, etc).
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Mon, 7 Apr 2014 22:38:00 +0000 (15:38 -0700)]
zram: drop `init_done' struct zram member
Introduce init_done() helper function which allows us to drop `init_done'
struct zram member. init_done() uses the fact that ->init_done == 1
equals to ->meta != NULL.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Mon, 7 Apr 2014 22:37:59 +0000 (15:37 -0700)]
mm/page_alloc.c: change mm debug routines back to EXPORT_SYMBOL
A new dump_page() routine was recently added, and marked
EXPORT_SYMBOL_GPL. dump_page() was also added to the VM_BUG_ON_PAGE()
macro, and so the end result is that non-GPL code can no longer call
get_page() and a few other routines.
This only happens if the kernel was compiled with CONFIG_DEBUG_VM.
Change dump_page() to be EXPORT_SYMBOL.
Longer explanation:
Prior to commit
309381feaee5 ("mm: dump page when hitting a VM_BUG_ON
using VM_BUG_ON_PAGE") , it was possible to build MIT-licensed (non-GPL)
drivers on Fedora. Fedora is semi-unique, in that it sets
CONFIG_VM_DEBUG.
Because Fedora sets CONFIG_VM_DEBUG, they end up pulling in dump_page(),
via VM_BUG_ON_PAGE, via get_page(). As one of the authors of NVIDIA's
new, open source, "UVM-Lite" kernel module, I originally choose to use
the kernel's get_page() routine from within nvidia_uvm_page_cache.c,
because get_page() has always seemed to be very clearly intended for use
by non-GPL, driver code.
So I'm hoping that making get_page() widely accessible again will not be
too controversial. We did check with Fedora first, and they responded
(https://bugzilla.redhat.com/show_bug.cgi?id=
1074710#c3) that we should
try to get upstream changed, before asking Fedora to change. Their
reasoning seems beneficial to Linux: leaving CONFIG_DEBUG_VM set allows
Fedora to help catch mm bugs.
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Srikar Dronamraju [Mon, 7 Apr 2014 22:37:57 +0000 (15:37 -0700)]
numa: use LAST_CPUPID_SHIFT to calculate LAST_CPUPID_MASK
LAST_CPUPID_MASK is calculated using LAST_CPUPID_WIDTH. However
LAST_CPUPID_WIDTH itself can be 0. (when LAST_CPUPID_NOT_IN_PAGE_FLAGS is
set). In such a case LAST_CPUPID_MASK turns out to be 0.
But with recent commit
1ae71d0319: (mm: numa: bugfix for
LAST_CPUPID_NOT_IN_PAGE_FLAGS) if LAST_CPUPID_MASK is 0,
page_cpupid_xchg_last() and page_cpupid_reset_last() causes
page->_last_cpupid to be set to 0.
This causes performance regression. Its almost as if numa_balancing is
off.
Fix LAST_CPUPID_MASK by using LAST_CPUPID_SHIFT instead of
LAST_CPUPID_WIDTH.
Some performance numbers and perf stats with and without the fix.
(3.14-rc6)
----------
numa01
Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa01':
12,27,462 cs [100.00%]
2,41,957 migrations [100.00%]
1,68,01,713 faults [100.00%]
7,99,35,29,041 cache-misses
98,808 migrate:mm_migrate_pages [100.00%]
1407.
690148814 seconds time elapsed
numa02
Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa02':
63,065 cs [100.00%]
14,364 migrations [100.00%]
2,08,118 faults [100.00%]
25,32,59,404 cache-misses
12 migrate:mm_migrate_pages [100.00%]
63.
840827219 seconds time elapsed
(3.14-rc6 with fix)
-------------------
numa01
Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa01':
9,68,911 cs [100.00%]
1,01,414 migrations [100.00%]
88,38,697 faults [100.00%]
4,42,92,51,042 cache-misses
4,25,060 migrate:mm_migrate_pages [100.00%]
685.
965331189 seconds time elapsed
numa02
Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa02':
17,543 cs [100.00%]
2,962 migrations [100.00%]
1,17,843 faults [100.00%]
11,80,61,644 cache-misses
12,358 migrate:mm_migrate_pages [100.00%]
20.
380132343 seconds time elapsed
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Zhang Yanfei [Mon, 7 Apr 2014 22:37:56 +0000 (15:37 -0700)]
madvise: correct the comment of MADV_DODUMP flag
s/MADV_NODUMP/MADV_DONTDUMP/
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:37:55 +0000 (15:37 -0700)]
mm/readahead.c: inline ra_submit
Commit
f9acc8c7b35a ("readahead: sanify file_ra_state names") left
ra_submit with a single function call.
Move ra_submit to internal.h and inline it to save some stack. Thanks
to Andrew Morton for commenting different versions.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mizuma, Masayoshi [Mon, 7 Apr 2014 22:37:54 +0000 (15:37 -0700)]
mm: hugetlb: fix softlockup when a large number of hugepages are freed.
When I decrease the value of nr_hugepage in procfs a lot, softlockup
happens. It is because there is no chance of context switch during this
process.
On the other hand, when I allocate a large number of hugepages, there is
some chance of context switch. Hence softlockup doesn't happen during
this process. So it's necessary to add the context switch in the
freeing process as same as allocating process to avoid softlockup.
When I freed 12 TB hugapages with kernel-2.6.32-358.el6, the freeing
process occupied a CPU over 150 seconds and following softlockup message
appeared twice or more.
$ echo
6000000 > /proc/sys/vm/nr_hugepages
$ cat /proc/sys/vm/nr_hugepages
6000000
$ grep ^Huge /proc/meminfo
HugePages_Total:
6000000
HugePages_Free:
6000000
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
$ echo 0 > /proc/sys/vm/nr_hugepages
BUG: soft lockup - CPU#16 stuck for 67s! [sh:12883] ...
Pid: 12883, comm: sh Not tainted 2.6.32-358.el6.x86_64 #1
Call Trace:
free_pool_huge_page+0xb8/0xd0
set_max_huge_pages+0x128/0x190
hugetlb_sysctl_handler_common+0x113/0x140
hugetlb_sysctl_handler+0x1e/0x20
proc_sys_call_handler+0x97/0xd0
proc_sys_write+0x14/0x20
vfs_write+0xb8/0x1a0
sys_write+0x51/0x90
__audit_syscall_exit+0x265/0x290
system_call_fastpath+0x16/0x1b
I have not confirmed this problem with upstream kernels because I am not
able to prepare the machine equipped with 12TB memory now. However I
confirmed that the amount of decreasing hugepages was directly
proportional to the amount of required time.
I measured required times on a smaller machine. It showed 130-145
hugepages decreased in a millisecond.
Amount of decreasing Required time Decreasing rate
hugepages (msec) (pages/msec)
------------------------------------------------------------
10,000 pages == 20GB 70 - 74 135-142
30,000 pages == 60GB 208 - 229 131-144
It means decrement of 6TB hugepages will trigger softlockup with the
default threshold 20sec, in this decreasing rate.
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Mon, 7 Apr 2014 22:37:53 +0000 (15:37 -0700)]
mm/memblock.c: use PFN_PHYS()
Replace ((phys_addr_t)(x) << PAGE_SHIFT) by pfn macro.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Emil Medve [Mon, 7 Apr 2014 22:37:52 +0000 (15:37 -0700)]
memblock: use for_each_memblock()
This is a small cleanup.
Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miklos Szeredi [Mon, 7 Apr 2014 22:37:51 +0000 (15:37 -0700)]
mm: remove unused arg of set_page_dirty_balance()
There's only one caller of set_page_dirty_balance() and that will call it
with page_mkwrite == 0.
The page_mkwrite argument was unused since commit
b827e496c893 "mm: close
page_mkwrite races".
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Mon, 7 Apr 2014 22:37:50 +0000 (15:37 -0700)]
mm: try_to_unmap_cluster() should lock_page() before mlocking
A BUG_ON(!PageLocked) was triggered in mlock_vma_page() by Sasha Levin
fuzzing with trinity. The call site try_to_unmap_cluster() does not lock
the pages other than its check_page parameter (which is already locked).
The BUG_ON in mlock_vma_page() is not documented and its purpose is
somewhat unclear, but apparently it serializes against page migration,
which could otherwise fail to transfer the PG_mlocked flag. This would
not be fatal, as the page would be eventually encountered again, but
NR_MLOCK accounting would become distorted nevertheless. This patch adds
a comment to the BUG_ON in mlock_vma_page() and munlock_vma_page() to that
effect.
The call site try_to_unmap_cluster() is fixed so that for page !=
check_page, trylock_page() is attempted (to avoid possible deadlocks as we
already have check_page locked) and mlock_vma_page() is performed only
upon success. If the page lock cannot be obtained, the page is left
without PG_mlocked, which is again not a problem in the whole unevictable
memory design.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:48 +0000 (15:37 -0700)]
mm: page_alloc: spill to remote nodes before waking kswapd
On NUMA systems, a node may start thrashing cache or even swap anonymous
pages while there are still free pages on remote nodes.
This is a result of commits
81c0a2bb515f ("mm: page_alloc: fair zone
allocator policy") and
fff4068cba48 ("mm: page_alloc: revert NUMA aspect
of fair allocation policy").
Before those changes, the allocator would first try all allowed zones,
including those on remote nodes, before waking any kswapds. But now,
the allocator fastpath doubles as the fairness pass, which in turn can
only consider the local node to prevent remote spilling based on
exhausted fairness batches alone. Remote nodes are only considered in
the slowpath, after the kswapds are woken up. But if remote nodes still
have free memory, kswapd should not be woken to rebalance the local node
or it may thrash cash or swap prematurely.
Fix this by adding one more unfair pass over the zonelist that is
allowed to spill to remote nodes after the local fairness pass fails but
before entering the slowpath and waking the kswapds.
This also gets rid of the GFP_THISNODE exemption from the fairness
protocol because the unfair pass is no longer tied to kswapd, which
GFP_THISNODE is not allowed to wake up.
However, because remote spills can be more frequent now - we prefer them
over local kswapd reclaim - the allocation batches on remote nodes could
underflow more heavily. When resetting the batches, use
atomic_long_read() directly instead of zone_page_state() to calculate the
delta as the latter filters negative counter values.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@kernel.org> [3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Mon, 7 Apr 2014 22:37:46 +0000 (15:37 -0700)]
memcg: rename high level charging functions
mem_cgroup_newpage_charge is used only for charging anonymous memory so
it is better to rename it to mem_cgroup_charge_anon.
mem_cgroup_cache_charge is used for file backed memory so rename it to
mem_cgroup_charge_file.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:45 +0000 (15:37 -0700)]
memcg: sanitize __mem_cgroup_try_charge() call protocol
Some callsites pass a memcg directly, some callsites pass an mm that
then has to be translated to a memcg. This makes for a terrible
function interface.
Just push the mm-to-memcg translation into the respective callsites and
always pass a memcg to mem_cgroup_try_charge().
[mhocko@suse.cz: add charge mm helper]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Mon, 7 Apr 2014 22:37:44 +0000 (15:37 -0700)]
memcg: do not replicate get_mem_cgroup_from_mm in __mem_cgroup_try_charge
__mem_cgroup_try_charge duplicates get_mem_cgroup_from_mm for charges
which came without a memcg. The only reason seems to be a tiny
optimization when css_tryget is not called if the charge can be consumed
from the stock. Nevertheless css_tryget is very cheap since it has been
reworked to use per-cpu counting so this optimization doesn't give us
anything these days.
So let's drop the code duplication so that the code is more readable.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:43 +0000 (15:37 -0700)]
memcg: get_mem_cgroup_from_mm()
Instead of returning NULL from try_get_mem_cgroup_from_mm() when the mm
owner is exiting, just return root_mem_cgroup. This makes sense for all
callsites and gets rid of some of them having to fallback manually.
[fengguang.wu@intel.com: fix warnings]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:42 +0000 (15:37 -0700)]
memcg: remove unnecessary !mm check from try_get_mem_cgroup_from_mm()
Users pass either a mm that has been established under task lock, or use
a verified current->mm, which means the task can't be exiting.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:41 +0000 (15:37 -0700)]
mm: memcg: push !mm handling out to page cache charge function
Only page cache charges can happen without an mm context, so push this
special case out of the inner core and into the cache charge function.
An ancient comment explains that the mm can also be NULL in case the
task is currently being migrated, but that is not actually true with the
current case, so just remove it.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:41 +0000 (15:37 -0700)]
mm: memcg: inline mem_cgroup_charge_common()
mem_cgroup_charge_common() is used by both cache and anon pages, but
most of its body only applies to anon pages and the remainder is not
worth having in a separate function.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:40 +0000 (15:37 -0700)]
mm: memcg: remove mem_cgroup_move_account_page_stat()
It used to disable preemption and run sanity checks but now it's only
taking a number out of one percpu counter and putting it into another.
Do this directly in the callsite and save the indirection.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 7 Apr 2014 22:37:39 +0000 (15:37 -0700)]
mm: memcg: remove unnecessary preemption disabling
lock_page_cgroup() disables preemption, remove explicit preemption
disabling for code paths holding this lock.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Mon, 7 Apr 2014 22:37:38 +0000 (15:37 -0700)]
mm: use 'const char *' insted of 'char *' for reason in dump_page()
I tried to use 'dump_page(page, __func__)' for debugging, but it triggers
warning:
warning: passing argument 2 of `dump_page' discards `const' qualifier from pointer target type [enabled by default]
Let's convert 'reason' to 'const char *' in dump_page() and friends: we
shouldn't modify it anyway.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Gioh Kim [Mon, 7 Apr 2014 22:37:37 +0000 (15:37 -0700)]
mm/vmalloc.c: enhance vm_map_ram() comment
vm_map_ram() has a fragmentation problem when it cannot purge a
chunk(ie, 4M address space) if there is a pinning object in that
addresss space. So it could consume all VMALLOC address space easily.
We can fix the fragmentation problem by using vmap instead of
vm_map_ram() but vmap() is known to be slow compared to vm_map_ram().
Minchan said vm_map_ram is 5 times faster than vmap in his tests. So I
thought we should fix fragment problem of vm_map_ram because our
proprietary GPU driver has used it heavily.
On second thought, it's not an easy because we should reuse freed space
for solving the problem and it could make more IPI and bitmap operation
for searching hole. It could mitigate API's goal which is very fast
mapping. And even fragmentation problem wouldn't show in 64 bit
machine.
Another option is that the user should separate long-life and short-life
object and use vmap for long-life but vm_map_ram for short-life. If we
inform the user about the characteristic of vm_map_ram the user can
choose one according to the page lifetime.
Let's add some notice messages to user.
[akpm@linux-foundation.org: tweak comment text]
Signed-off-by: Gioh Kim <gioh.kim@lge.com>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Choi Gi-yong [Mon, 7 Apr 2014 22:37:36 +0000 (15:37 -0700)]
mm: fix 'ERROR: do not initialise globals to 0 or NULL' and coding style
Signed-off-by: Choi Gi-yong <yong@gnoy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mikulas Patocka [Mon, 7 Apr 2014 22:37:35 +0000 (15:37 -0700)]
mempool: add unlikely and likely hints
Add unlikely and likely hints to the function mempool_free. It lays out
the code in such a way that the common path is executed straighforward and
saves a cache line.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Mon, 7 Apr 2014 22:37:34 +0000 (15:37 -0700)]
mm, compaction: determine isolation mode only once
The conditions that control the isolation mode in
isolate_migratepages_range() do not change during the iteration, so
extract them out and only define the value once.
This actually does have an effect, gcc doesn't optimize it itself because
of cc->sync.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Mon, 7 Apr 2014 22:37:32 +0000 (15:37 -0700)]
res_counter: remove interface for locked charging and uncharging
The res_counter_{charge,uncharge}_locked() variants are not used in the
kernel outside of the resource counter code itself, so remove the
interface.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Tim Hockin <thockin@google.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Mon, 7 Apr 2014 22:37:30 +0000 (15:37 -0700)]
mm, mempolicy: remove per-process flag
PF_MEMPOLICY is an unnecessary optimization for CONFIG_SLAB users.
There's no significant performance degradation to checking
current->mempolicy rather than current->flags & PF_MEMPOLICY in the
allocation path, especially since this is considered unlikely().
Running TCP_RR with netperf-2.4.5 through localhost on 16 cpu machine with
64GB of memory and without a mempolicy:
threads before after
16
1249409 1244487
32
1281786 1246783
48
1239175 1239138
64
1244642 1241841
80
1244346 1248918
96
1266436 1254316
112
1307398 1312135
128
1327607 1326502
Per-process flags are a scarce resource so we should free them up whenever
possible and make them available. We'll be using it shortly for memcg oom
reserves.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Tim Hockin <thockin@google.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Mon, 7 Apr 2014 22:37:29 +0000 (15:37 -0700)]
mm, mempolicy: rename slab_node for clarity
slab_node() is actually a mempolicy function, so rename it to
mempolicy_slab_node() to make it clearer that it used for processes with
mempolicies.
At the same time, cleanup its code by saving numa_mem_id() in a local
variable (since we require a node with memory, not just any node) and
remove an obsolete comment that assumes the mempolicy is actually passed
into the function.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Tim Hockin <thockin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Mon, 7 Apr 2014 22:37:27 +0000 (15:37 -0700)]
fork: collapse copy_flags into copy_process
copy_flags() does not use the clone_flags formal and can be collapsed
into copy_process() for cleaner code.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Tim Hockin <thockin@google.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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