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authorEric Dumazet <eric.dumazet@gmail.com>2010-10-08 10:37:34 +0400
committerDavid S. Miller <davem@davemloft.net>2010-10-12 00:06:53 +0400
commitfc66f95c68b6d4535a0ea2ea15d5cf626e310956 (patch)
treeac3a7f08ad741a67ff683bf93e5669ddcae95ed7 /net/decnet
parent0ed8ddf4045fcfcac36bad753dc4046118c603ec (diff)
downloadlinux-fc66f95c68b6d4535a0ea2ea15d5cf626e310956.tar.xz
net dst: use a percpu_counter to track entries
struct dst_ops tracks number of allocated dst in an atomic_t field, subject to high cache line contention in stress workload. Switch to a percpu_counter, to reduce number of time we need to dirty a central location. Place it on a separate cache line to avoid dirtying read only fields. Stress test : (Sending 160.000.000 UDP frames, IP route cache disabled, dual E5540 @2.53GHz, 32bit kernel, FIB_TRIE, SLUB/NUMA) Before: real 0m51.179s user 0m15.329s sys 10m15.942s After: real 0m45.570s user 0m15.525s sys 9m56.669s With a small reordering of struct neighbour fields, subject of a following patch, (to separate refcnt from other read mostly fields) real 0m41.841s user 0m15.261s sys 8m45.949s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/decnet')
-rw-r--r--net/decnet/dn_route.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 6585ea6d1182..df0f3e54ff8a 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -132,7 +132,6 @@ static struct dst_ops dn_dst_ops = {
.negative_advice = dn_dst_negative_advice,
.link_failure = dn_dst_link_failure,
.update_pmtu = dn_dst_update_pmtu,
- .entries = ATOMIC_INIT(0),
};
static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
@@ -1758,6 +1757,7 @@ void __init dn_route_init(void)
dn_dst_ops.kmem_cachep =
kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+ dst_entries_init(&dn_dst_ops);
setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
add_timer(&dn_route_timer);
@@ -1816,5 +1816,6 @@ void __exit dn_route_cleanup(void)
dn_run_flush(0);
proc_net_remove(&init_net, "decnet_cache");
+ dst_entries_destroy(&dn_dst_ops);
}