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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-10-08 06:37:34 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-10-11 13:06:53 -0700 |
| commit | fc66f95c68b6d4535a0ea2ea15d5cf626e310956 (patch) | |
| tree | ac3a7f08ad741a67ff683bf93e5669ddcae95ed7 /net/decnet | |
| parent | 0ed8ddf4045fcfcac36bad753dc4046118c603ec (diff) | |
| download | lwn-fc66f95c68b6d4535a0ea2ea15d5cf626e310956.tar.gz lwn-fc66f95c68b6d4535a0ea2ea15d5cf626e310956.zip | |
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.c | 3 |
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); } |