On Mon, Jun 09, 2003 at 02:01:16AM -0700, David S. Miller wrote: > From: Simon Kirby <sim@netnation.com> > 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)); gcc will generate a lot better code for the memsets if you can tell it somehow they are long aligned and a multiple of 8 bytes. e.g. redeclare them as long instead of char. If it cannot figure out the alignment it often (or least on x86) calls to the external memset function. > 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)); Same here. -Andi - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
