Commit cd39a789 authored Jan 28, 2013 by Jesper Dangaard Brouer Committed by David S. Miller Jan 29, 2013

net: cacheline adjust struct netns_frags for better frag performance



This small cacheline adjustment of struct netns_frags improves
performance significantly for the fragmentation code.

Struct members 'lru_list' and 'mem' are both hot elements, and it
hurts performance, due to cacheline bouncing at every call point,
when they share a cacheline.  Also notice, how mem is placed
together with 'high_thresh' and 'low_thresh', as they are used in
the compare operations together.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 656a05c8

include/net/inet_frag.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -3,9 +3,12 @@

		struct netns_frags {
		int nqueues;
		atomic_t mem;
		struct list_head lru_list;

		/* Its important for performance to keep lru_list and mem on
		* separate cachelines
		*/
		atomic_t mem ____cacheline_aligned_in_smp;
		/* sysctls */
		int timeout;
		int high_thresh;