From: James Morse Date: Sat, 10 Sep 2016 10:34:14 +0000 (+1000) Subject: mm/memcontrol.c: make the walk_page_range() limit obvious X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=659601d5e8c790166b9baf8024abb1a38a162d0b;p=deliverable%2Flinux.git mm/memcontrol.c: make the walk_page_range() limit obvious mem_cgroup_count_precharge() and mem_cgroup_move_charge() both call walk_page_range() on the range 0 to ~0UL, neither provide a pte_hole callback, which causes the current implementation to skip non-vma regions. This is all fine but follow up changes would like to make walk_page_range more generic so it is better to be explicit about which range to traverse so let's use highest_vm_end to explicitly traverse only user mmaped memory. [mhocko@kernel.org: rewrote changelog] Link: http://lkml.kernel.org/r/1472655897-22532-1-git-send-email-james.morse@arm.com Signed-off-by: James Morse Acked-by: Naoya Horiguchi Cc: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Signed-off-by: Andrew Morton --- diff --git a/mm/memcontrol.c b/mm/memcontrol.c index bdb796fd85f4..d150f70dc199 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4668,7 +4668,8 @@ static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) .mm = mm, }; down_read(&mm->mmap_sem); - walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk); + walk_page_range(0, mm->highest_vm_end, + &mem_cgroup_count_precharge_walk); up_read(&mm->mmap_sem); precharge = mc.precharge; @@ -4956,7 +4957,8 @@ retry: * When we have consumed all precharges and failed in doing * additional charge, the page walk just aborts. */ - walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk); + walk_page_range(0, mc.mm->highest_vm_end, &mem_cgroup_move_charge_walk); + up_read(&mc.mm->mmap_sem); atomic_dec(&mc.from->moving_account); }