From: Johannes Weiner <han...@cmpxchg.org> Transparent huge page charges prefer falling back to regular pages rather than spending a lot of time in direct reclaim.
Desired reclaim behavior is usually declared in the gfp mask, but THP charges use GFP_KERNEL and then rely on the fact that OOM is disabled for THP charges, and that OOM-disabled charges don't retry reclaim. Needless to say, this is anything but obvious and quite error prone. Convert THP charges to use GFP_TRANSHUGE instead, which implies __GFP_NORETRY, to indicate the low-latency requirement. Signed-off-by: Johannes Weiner <han...@cmpxchg.org> Acked-by: Michal Hocko <mho...@suse.cz> Cc: Hugh Dickins <hu...@google.com> Cc: Tejun Heo <t...@kernel.org> Cc: Vladimir Davydov <vdavy...@parallels.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> https://jira.sw.ru/browse/PSBM-51558 (cherry picked from commit d51d885bbb137cc8e1704e76be1846c5e0d5e8b4) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- mm/huge_memory.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 3c23df1..daa8a144 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -716,7 +716,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, VM_BUG_ON_PAGE(!PageCompound(page), page); - if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { + if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_TRANSHUGE))) { put_page(page); count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; @@ -1203,7 +1203,7 @@ alloc: goto out; } - if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) { + if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_TRANSHUGE))) { put_page(new_page); if (page) { split_huge_page(page); @@ -2468,7 +2468,7 @@ static void collapse_huge_page(struct mm_struct *mm, if (!new_page) return; - if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) + if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_TRANSHUGE))) return; /* -- 2.7.3 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel