From fc66f95c68b6d4535a0ea2ea15d5cf626e310956 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 8 Oct 2010 06:37:34 +0000 Subject: 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 Signed-off-by: David S. Miller --- net/ipv6/xfrm6_policy.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'net/ipv6/xfrm6_policy.c') diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c index 39676eac3a37..7e74023ea6e4 100644 --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -199,7 +199,7 @@ static inline int xfrm6_garbage_collect(struct dst_ops *ops) struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); xfrm6_policy_afinfo.garbage_collect(net); - return atomic_read(&ops->entries) > ops->gc_thresh * 2; + return dst_entries_get_fast(ops) > ops->gc_thresh * 2; } static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) @@ -255,7 +255,6 @@ static struct dst_ops xfrm6_dst_ops = { .ifdown = xfrm6_dst_ifdown, .local_out = __ip6_local_out, .gc_thresh = 1024, - .entries = ATOMIC_INIT(0), }; static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { @@ -312,11 +311,13 @@ int __init xfrm6_init(void) */ gc_thresh = FIB6_TABLE_HASHSZ * 8; xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; + dst_entries_init(&xfrm6_dst_ops); ret = xfrm6_policy_init(); - if (ret) + if (ret) { + dst_entries_destroy(&xfrm6_dst_ops); goto out; - + } ret = xfrm6_state_init(); if (ret) goto out_policy; @@ -341,4 +342,5 @@ void xfrm6_fini(void) //xfrm6_input_fini(); xfrm6_policy_fini(); xfrm6_state_fini(); + dst_entries_destroy(&xfrm6_dst_ops); } -- cgit v1.2.3