From: Eric Dumazet Date: Tue, 6 Nov 2007 07:38:39 +0000 (-0800) Subject: [NET]: Define infrastructure to keep 'inuse' changes in an efficent SMP/NUMA way. X-Git-Tag: v2.6.24-rc3~179^2~29 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=286ab3d46058840d68e5d7d52e316c1f7e98c59f;p=pandora-kernel.git [NET]: Define infrastructure to keep 'inuse' changes in an efficent SMP/NUMA way. "struct proto" currently uses an array stats[NR_CPUS] to track change on 'inuse' sockets per protocol. If NR_CPUS is big, this means we use a big memory area for this. Moreover, all this memory area is located on a single node on NUMA machines, increasing memory pressure on the boot node. In this patch, I tried to : - Keep a fast !CONFIG_SMP implementation - Keep a fast CONFIG_SMP implementation for often used protocols (tcp,udp,raw,...) - Introduce a NUMA efficient implementation Some helper macros are defined in include/net/sock.h These macros take into account CONFIG_SMP If a "struct proto" is declared without using DEFINE_PROTO_INUSE / REF_PROTO_INUSE macros, it will automatically use a default implementation, using a dynamically allocated percpu zone. This default implementation will be NUMA efficient, but might use 32/64 bytes per possible cpu because of current alloc_percpu() implementation. However it still should be better than previous implementation based on stats[NR_CPUS] field. When a "struct proto" is changed to use the new macros, we use a single static "int" percpu variable, lowering the memory and cpu costs, still preserving NUMA efficiency. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- Reading git-diff-tree failed