someOS/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

netns: reorder fields in struct net

Browse Source 
In a network bench, I noticed an unfortunate false sharing between
'loopback_dev' and 'count' fields in "struct net".

'count' is written each time a socket is created or destroyed, while
loopback_dev might be often read in routing code.

Move loopback_dev in a read mostly section of "struct net"

Note: struct netns_xfrm is cache line aligned on SMP.
(It contains a "struct dst_ops")
Move it at the end to avoid holes, and reduce sizeof(struct net) by 128
bytes on ia32.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2010-10-14 05:56:18 +00:00
committed by David S. Miller
parent c60ce4e265
commit 8e602ce298
2 changed files with 15 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
include/net/netns/xfrm.h
View File

@@ -43,10 +43,6 @@ struct netns_xfrm {
unsigned int policy_count[XFRM_POLICY_MAX * 2];
struct work_struct policy_hash_work;
struct dst_ops xfrm4_dst_ops;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
struct dst_ops xfrm6_dst_ops;
#endif
struct sock *nlsk;
struct sock *nlsk_stash;
@@ -58,6 +54,11 @@ struct netns_xfrm {
#ifdef CONFIG_SYSCTL
struct ctl_table_header *sysctl_hdr;
#endif
struct dst_ops xfrm4_dst_ops;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
struct dst_ops xfrm6_dst_ops;
#endif
};
#endif