Re: Route cache performance under stress
From: David S. Miller <hidden>
Date: 2003-06-09 09:01:16
Possibly related (same subject, not in this thread)
- 2003-06-10 · Re: Route cache performance under stress · chas williams <hidden>
- 2003-06-10 · Re: Route cache performance under stress · David S. Miller <hidden>
- 2003-06-10 · Re: Route cache performance under stress · chas williams <hidden>
- 2003-04-05 · Re: Route cache performance under stress · Martin Josefsson <hidden>
From: Simon Kirby [off-list ref]
Date: Mon, 9 Jun 2003 01:18:03 -0700
10516 dst_alloc 73.0278
Gross, we effectively initialize a new dst multiple times :(
In fact, we modify the same cache lines at least 3 times.
There's a lot more we can do in this area. But this patch below kills
some of it. Again, patch is against 2.5.x-current.
Actually, it is a relatively good sign, it means this is a relatively
unexplored area of the networking :-)))
--- net/core/dst.c.~1~ Mon Jun 9 01:47:26 2003
+++ net/core/dst.c Mon Jun 9 01:53:41 2003@@ -122,13 +122,31 @@ void * dst_alloc(struct dst_ops * ops) dst = kmem_cache_alloc(ops->kmem_cachep, SLAB_ATOMIC); if (!dst) return NULL; - memset(dst, 0, ops->entry_size); + dst->next = NULL; atomic_set(&dst->__refcnt, 0); - dst->ops = ops; + dst->__use = 0; + dst->child = NULL; + dst->dev = NULL; + dst->obsolete = 0; + dst->flags = 0; dst->lastuse = jiffies; + dst->expires = 0; + dst->header_len = 0; + dst->trailer_len = 0; + memset(dst->metrics, 0, sizeof(dst->metrics)); dst->path = dst; + dst->rate_last = 0; + dst->rate_tokens = 0; + dst->error = 0; + dst->neighbour = NULL; + dst->hh = NULL; + dst->xfrm = NULL; dst->input = dst_discard; dst->output = dst_blackhole; + dst->ops = ops; + INIT_RCU_HEAD(&dst->rcu_head); + memset(dst->info, 0, + ops->entry_size - offsetof(struct dst_entry, info)); #if RT_CACHE_DEBUG >= 2 atomic_inc(&dst_total); #endif