Messages in this thread | | | Date | Tue, 25 Feb 2014 15:50:27 -0500 (EST) | Subject | Re: [PATCH] net: use __GFP_NORETRY for high order allocations | From | David Miller <> |
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From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 07 Feb 2014 16:22:56 -0800
> David Miller <davem@davemloft.net> writes: > >> From: Eric Dumazet <eric.dumazet@gmail.com> >> Date: Thu, 06 Feb 2014 10:42:42 -0800 >> >>> From: Eric Dumazet <edumazet@google.com> >>> >>> 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 : >> ... >>> Signed-off-by: Eric Dumazet <edumazet@google.com> >>> Acked-by: David Rientjes <rientjes@google.com> >> >> Applied, do we want this for -stable? > > The first hunk goes back to 3.12 and the second hunk goes back to 3.8. > > I think so. The change is safe and this class of problem can cause an > external attack to trigger an OOM on your box, by controlling the packet > flow.
Great, I'm working integrating this into my -stable queue right now.
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