From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: [patch 03/12] mm: huge_memory: use GFP_TRANSHUGE when charging huge pages Date: Mon, 16 Jun 2014 15:54:23 -0400 Message-ID: <1402948472-8175-4-git-send-email-hannes@cmpxchg.org> References: <1402948472-8175-1-git-send-email-hannes@cmpxchg.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=cmpxchg.org; s=zene; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=KyrCpZdI2/moLhgQ0TH5G8hnpB+Cs8wPpubN/CfCIYE=; b=gdutPfg3mWZeTX2PbqPFsMGUtXRhmZyJvHNGgVy04nAt8mdQzZH8U6EtXcclddeLX7Dy5yiXHMbxVFLrXAGUaO5hnhYBIP5/QreQLZP99Grt1DQ4qrTix43kYTpGNzxTVWu6zcTR9JaxGyaK4O66jSw6awGE8AAcMa+4xcmHVH4=; In-Reply-To: <1402948472-8175-1-git-send-email-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: Michal Hocko , Hugh Dickins , Tejun Heo , Vladimir Davydov , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.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 currently skip 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 --- 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 e60837dc785c..10cd7f2bf776 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -827,7 +827,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } - if (unlikely(mem_cgroup_charge_anon(page, mm, GFP_KERNEL))) { + if (unlikely(mem_cgroup_charge_anon(page, mm, GFP_TRANSHUGE))) { put_page(page); count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; @@ -1101,7 +1101,7 @@ alloc: goto out; } - if (unlikely(mem_cgroup_charge_anon(new_page, mm, GFP_KERNEL))) { + if (unlikely(mem_cgroup_charge_anon(new_page, mm, GFP_TRANSHUGE))) { put_page(new_page); if (page) { split_huge_page(page); @@ -2368,7 +2368,7 @@ static void collapse_huge_page(struct mm_struct *mm, if (!new_page) return; - if (unlikely(mem_cgroup_charge_anon(new_page, mm, GFP_KERNEL))) + if (unlikely(mem_cgroup_charge_anon(new_page, mm, GFP_TRANSHUGE))) return; /* -- 2.0.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org