From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755402AbbIYHpV (ORCPT ); Fri, 25 Sep 2015 03:45:21 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:34832 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753874AbbIYHpT (ORCPT ); Fri, 25 Sep 2015 03:45:19 -0400 From: Greg Thelen To: Alexander Viro , Andrew Morton Cc: David Rientjes , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Thelen Subject: [PATCH] fs, seqfile: always allow oom killer Date: Fri, 25 Sep 2015 00:43:54 -0700 Message-Id: <1443167034-67530-1-git-send-email-gthelen@google.com> X-Mailer: git-send-email 2.6.0.rc2.230.g3dd15c0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 5cec38ac866b ("fs, seq_file: fallback to vmalloc instead of oom kill processes") seq_buf_alloc() avoids calling the oom killer for PAGE_SIZE or smaller allocations; but larger allocations can use the oom killer via vmalloc(). Thus reads of small files can return ENOMEM, but larger files use the oom killer to avoid ENOMEM. Memory overcommit requires use of the oom killer to select a victim regardless of file size. Enable oom killer for small seq_buf_alloc() allocations. Signed-off-by: David Rientjes Signed-off-by: Greg Thelen --- fs/seq_file.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/seq_file.c b/fs/seq_file.c index 225586e141ca..a8e288755f24 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -25,12 +25,17 @@ static void seq_set_overflow(struct seq_file *m) static void *seq_buf_alloc(unsigned long size) { void *buf; + gfp_t gfp = GFP_KERNEL; /* - * __GFP_NORETRY to avoid oom-killings with high-order allocations - - * it's better to fall back to vmalloc() than to kill things. + * For high order allocations, use __GFP_NORETRY to avoid oom-killing - + * it's better to fall back to vmalloc() than to kill things. For small + * allocations, just use GFP_KERNEL which will oom kill, thus no need + * for vmalloc fallback. */ - buf = kmalloc(size, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN); + if (size > PAGE_SIZE) + gfp |= __GFP_NORETRY | __GFP_NOWARN; + buf = kmalloc(size, gfp); if (!buf && size > PAGE_SIZE) buf = vmalloc(size); return buf; -- 2.6.0.rc2.230.g3dd15c0