From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f48.google.com (mail-ee0-f48.google.com [74.125.83.48]) by kanga.kvack.org (Postfix) with ESMTP id 267636B0055 for ; Fri, 18 Apr 2014 10:50:51 -0400 (EDT) Received: by mail-ee0-f48.google.com with SMTP id b57so1676010eek.7 for ; Fri, 18 Apr 2014 07:50:50 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id z2si40594441eeo.124.2014.04.18.07.50.49 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 18 Apr 2014 07:50:49 -0700 (PDT) From: Mel Gorman Subject: [PATCH 12/16] mm: shmem: Avoid atomic operation during shmem_getpage_gfp Date: Fri, 18 Apr 2014 15:50:39 +0100 Message-Id: <1397832643-14275-13-git-send-email-mgorman@suse.de> In-Reply-To: <1397832643-14275-1-git-send-email-mgorman@suse.de> References: <1397832643-14275-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Linux-MM Cc: Linux-FSDevel shmem_getpage_gfp uses an atomic operation to set the SwapBacked field before it's even added to the LRU or visible. This is unnecessary as what could it possible race against? Use an unlocked variant. Signed-off-by: Mel Gorman --- include/linux/page-flags.h | 1 + mm/shmem.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index d1fe1a7..4d4b39a 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -208,6 +208,7 @@ PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */ PAGEFLAG(SavePinned, savepinned); /* Xen */ PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked) + __SETPAGEFLAG(SwapBacked, swapbacked) __PAGEFLAG(SlobFree, slob_free) diff --git a/mm/shmem.c b/mm/shmem.c index 9f70e02..f47fb38 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1132,7 +1132,7 @@ repeat: goto decused; } - SetPageSwapBacked(page); + __SetPageSwapBacked(page); __set_page_locked(page); error = mem_cgroup_charge_file(page, current->mm, gfp & GFP_RECLAIM_MASK); -- 1.8.4.5 -- 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