X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=init%2FKconfig;h=bb9b4dd55889f0605b07ddfc73cc105d72b18908;hb=bd1a05ee98b06c9a20138c45f96ccfddf3163f93;hp=af09b4fb43d291856708eb78197adb74dd1b4f48;hpb=1ea2a01c1db326f5b594ac086255ed2d9387603b;p=deliverable%2Flinux.git

diff --git a/init/Kconfig b/init/Kconfig
index af09b4fb43d2..bb9b4dd55889 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -538,15 +538,6 @@ config RCU_STALL_COMMON
 config CONTEXT_TRACKING
        bool
 
-config RCU_USER_QS
-	bool
-	help
-	  This option sets hooks on kernel / userspace boundaries and
-	  puts RCU in extended quiescent state when the CPU runs in
-	  userspace. It means that when a CPU runs in userspace, it is
-	  excluded from the global RCU state machine and thus doesn't
-	  try to keep the timer tick on for RCU.
-
 config CONTEXT_TRACKING_FORCE
 	bool "Force context tracking"
 	depends on CONTEXT_TRACKING
@@ -707,6 +698,7 @@ config RCU_BOOST_DELAY
 config RCU_NOCB_CPU
 	bool "Offload RCU callback processing from boot-selected CPUs"
 	depends on TREE_RCU || PREEMPT_RCU
+	depends on RCU_EXPERT || NO_HZ_FULL
 	default n
 	help
 	  Use this option to reduce OS jitter for aggressive HPC or
@@ -955,6 +947,22 @@ config CGROUP_FREEZER
 	  Provides a way to freeze and unfreeze all tasks in a
 	  cgroup.
 
+config CGROUP_PIDS
+	bool "PIDs cgroup subsystem"
+	help
+	  Provides enforcement of process number limits in the scope of a
+	  cgroup. Any attempt to fork more processes than is allowed in the
+	  cgroup will fail. PIDs are fundamentally a global resource because it
+	  is fairly trivial to reach PID exhaustion before you reach even a
+	  conservative kmemcg limit. As a result, it is possible to grind a
+	  system to halt without being limited by other cgroup policies. The
+	  PIDs cgroup subsystem is designed to stop this from happening.
+
+	  It should be noted that organisational operations (such as attaching
+	  to a cgroup hierarchy will *not* be blocked by the PIDs subsystem),
+	  since the PIDs limit only affects a process's ability to fork, not to
+	  attach to a cgroup.
+
 config CGROUP_DEVICE
 	bool "Device controller for cgroups"
 	help