diff options
| 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/core | |
| parent | 0ed8ddf4045fcfcac36bad753dc4046118c603ec (diff) | |
| download | linux-fc66f95c68b6d4535a0ea2ea15d5cf626e310956.tar.gz | |
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/core')
| -rw-r--r-- | net/core/dst.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/core/dst.c b/net/core/dst.c index 978a1ee1f7d0..32e542d7f472 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -168,7 +168,7 @@ void *dst_alloc(struct dst_ops *ops) { struct dst_entry *dst; - if (ops->gc && atomic_read(&ops->entries) > ops->gc_thresh) { + if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) { if (ops->gc(ops)) return NULL; } @@ -183,7 +183,7 @@ void *dst_alloc(struct dst_ops *ops) #if RT_CACHE_DEBUG >= 2 atomic_inc(&dst_total); #endif - atomic_inc(&ops->entries); + dst_entries_add(ops, 1); return dst; } EXPORT_SYMBOL(dst_alloc); @@ -236,7 +236,7 @@ again: neigh_release(neigh); } - atomic_dec(&dst->ops->entries); + dst_entries_add(dst->ops, -1); if (dst->ops->destroy) dst->ops->destroy(dst); |