From: James Morse Date: Sat, 8 Oct 2016 00:00:12 +0000 (-0700) Subject: mm/memcontrol.c: make the walk_page_range() limit obvious X-Git-Tag: v4.9-rc1~73^2~60 X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=0247f3f4d78a475cd3181dc9fc162fdef773aaaa 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 Signed-off-by: Linus Torvalds --- diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5579e762b1ce..0739d4129a93 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4681,7 +4681,8 @@ 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; @@ -4969,7 +4970,8 @@ 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); }