From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752194AbaDAQJ0 (ORCPT ); Tue, 1 Apr 2014 12:09:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:44348 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751817AbaDAQJF (ORCPT ); Tue, 1 Apr 2014 12:09:05 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.8 15/86] net: use __GFP_NORETRY for high order allocations Date: Tue, 1 Apr 2014 09:07:28 -0700 Message-Id: <1396368519-12728-16-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1396368519-12728-1-git-send-email-kamal@canonical.com> References: <1396368519-12728-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.21 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit ed98df3361f059db42786c830ea96e2d18b8d4db ] sock_alloc_send_pskb() & sk_page_frag_refill() have a loop trying high order allocations to prepare skb with low number of fragments as this increases performance. Problem is that under memory pressure/fragmentation, this can trigger OOM while the intent was only to try the high order allocations, then fallback to order-0 allocations. We had various reports from unexpected regressions. According to David, setting __GFP_NORETRY should be fine, as the asynchronous compaction is still enabled, and this will prevent OOM from kicking as in : CFSClientEventm invoked oom-killer: gfp_mask=0x42d0, order=3, oom_adj=0, oom_score_adj=0, oom_score_badness=2 (enabled),memcg_scoring=disabled CFSClientEventm Call Trace: [] dump_header+0xe1/0x23e [] oom_kill_process+0x6a/0x323 [] out_of_memory+0x4b3/0x50d [] __alloc_pages_may_oom+0xa2/0xc7 [] __alloc_pages_nodemask+0x1002/0x17f0 [] alloc_pages_current+0x103/0x2b0 [] sk_page_frag_refill+0x8f/0x160 [] tcp_sendmsg+0x560/0xee0 [] inet_sendmsg+0x67/0x100 [] __sock_sendmsg_nosec+0x6c/0x90 [] sock_sendmsg+0xc5/0xf0 [] __sys_sendmsg+0x136/0x430 [] sys_sendmsg+0x88/0x110 [] system_call_fastpath+0x16/0x1b Out of Memory: Kill process 2856 (bash) score 9999 or sacrifice child Signed-off-by: Eric Dumazet Acked-by: David Rientjes Acked-by: "Eric W. Biederman" Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/core/sock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/sock.c b/net/core/sock.c index 7367c05..68aad38 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1801,7 +1801,7 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag) gfp_t gfp = sk->sk_allocation; if (order) - gfp |= __GFP_COMP | __GFP_NOWARN; + gfp |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY; pfrag->page = alloc_pages(gfp, order); if (likely(pfrag->page)) { pfrag->offset = 0; -- 1.8.3.2