From 4b9d9be839fdb7dcd7ce7619a623fd9015a50cda Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 8 Jun 2011 13:35:34 +0000 Subject: 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 --- include/net/ip.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/net/ip.h') diff --git a/include/net/ip.h b/include/net/ip.h index 66dd491..e9ea7c7 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -228,8 +228,6 @@ extern struct ctl_path net_ipv4_ctl_path[]; extern int inet_peer_threshold; extern int inet_peer_minttl; extern int inet_peer_maxttl; -extern int inet_peer_gc_mintime; -extern int inet_peer_gc_maxtime; /* From ip_output.c */ extern int sysctl_ip_dynaddr; -- cgit v1.1