From: Eric Dumazet Date: Wed, 8 Jun 2011 13:35:34 +0000 (+0000) Subject: inetpeer: remove unused list X-Git-Tag: v3.1-rc1~316^2~450^2~52 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b9d9be839fdb7dcd7ce7619a623fd9015a50cda;p=pandora-kernel.git inetpeer: remove unused list Andi Kleen and Tim Chen reported huge contention on inetpeer unused_peers.lock, on memcached workload on a 40 core machine, with disabled route cache. It appears we constantly flip peers refcnt between 0 and 1 values, and we must insert/remove peers from unused_peers.list, holding a contended spinlock. Remove this list completely and perform a garbage collection on-the-fly, at lookup time, using the expired nodes we met during the tree traversal. This removes a lot of code, makes locking more standard, and obsoletes two sysctls (inet_peer_gc_mintime and inet_peer_gc_maxtime). This also removes two pointers in inet_peer structure. There is still a false sharing effect because refcnt is in first cache line of object [were the links and keys used by lookups are located], we might move it at the end of inet_peer structure to let this first cache line mostly read by cpus. Signed-off-by: Eric Dumazet CC: Andi Kleen CC: Tim Chen Signed-off-by: David S. Miller --- Reading git-diff-tree failed