lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20140829.202923.1151165186886866910.davem@davemloft.net> Date: Fri, 29 Aug 2014 20:29:23 -0700 (PDT) From: David Miller <davem@...emloft.net> To: eric.dumazet@...il.com Cc: rientjes@...gle.com, netdev@...r.kernel.org Subject: Re: [PATCH] net: attempt a single high order allocation From: Eric Dumazet <eric.dumazet@...il.com> Date: Wed, 27 Aug 2014 20:49:34 -0700 > From: Eric Dumazet <edumazet@...gle.com> > > In commit ed98df3361f0 ("net: use __GFP_NORETRY for high order > allocations") we tried to address one issue caused by order-3 > allocations. > > We still observe high latencies and system overhead in situations where > compaction is not successful. > > Instead of trying order-3, order-2, and order-1, do a single order-3 > best effort and immediately fallback to plain order-0. > > This mimics slub strategy to fallback to slab min order if the high > order allocation used for performance failed. > > Order-3 allocations give a performance boost only if they can be done > without recurring and expensive memory scan. > > Quoting David : > > The page allocator relies on synchronous (sync light) memory compaction > after direct reclaim for allocations that don't retry and deferred > compaction doesn't work with this strategy because the allocation order > is always decreasing from the previous failed attempt. > > This means sync light compaction will always be encountered if memory > cannot be defragmented or reclaimed several times during the > skb_page_frag_refill() iteration. > > Signed-off-by: Eric Dumazet <edumazet@...gle.com> > Acked-by: David Rientjes <rientjes@...gle.com> Applied, thanks Eric. Do you want me to queue this up for -stable? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists