From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Subject: Re: Route cache performance under stress Date: Mon, 9 Jun 2003 09:22:11 -0400 (EDT) Sender: linux-net-owner@vger.kernel.org Message-ID: <20030609091907.Y34702@shell.cyberus.ca> References: <20030609072227.R34462@shell.cyberus.ca> <20030609.045547.91327851.davem@redhat.com> <20030609080430.I34540@shell.cyberus.ca> <20030609.053218.54202815.davem@redhat.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: xerox@foonet.net, sim@netnation.com, fw@deneb.enyo.de, netdev@oss.sgi.com, linux-net@vger.kernel.org Return-path: To: "David S. Miller" In-Reply-To: <20030609.053218.54202815.davem@redhat.com> List-Id: netdev.vger.kernel.org On Mon, 9 Jun 2003, David S. Miller wrote: > From: Jamal Hadi > Date: Mon, 9 Jun 2003 08:18:50 -0400 (EDT) > > I found in my tests with a ethernet driver that prefetching the > _next_ dma descriptor gave better numbers than prefetching the > current one but i didnt spend too much time. > > Two issues: > > 1) We have some cycles to borrow for head entry, we can make > prefetch right before rcu_read_lock() > > 2) Ideally, hash chains will not exceed 1 (2 at the max) > entries. > I dont think youll see much benefit with 1 or 2 entries. I was thinking more along the lines of people with over 100K entries total; Let me run with this and get back to you. cheers, jamal