From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: TCP IP Offloading Interface Date: Sun, 13 Jul 2003 17:24:14 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <20030713172414.5c888094.davem@redhat.com> References: <20030713004818.4f1895be.davem@redhat.com> <52u19qwg53.fsf@topspin.com> <20030713160200.571716cf.davem@redhat.com> <20030713233503.GA31793@work.bitmover.com> <20030713164003.21839eb4.davem@redhat.com> <20030713235424.GB31793@work.bitmover.com> <20030713165323.3fc2601f.davem@redhat.com> <20030714002200.GA24697@work.bitmover.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: lm@bitmover.com, roland@topspin.com, alan@storlinksemi.com, linux-kernel@vger.kernel.org, linux-net@vger.kernel.org, netdev@oss.sgi.com Return-path: To: Larry McVoy In-Reply-To: <20030714002200.GA24697@work.bitmover.com> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Sun, 13 Jul 2003 17:22:00 -0700 Larry McVoy wrote: > Hey, maybe it isn't, but could you please quantify the cost of the VM > operations? How hard is that? Ok. So the page is in a non-uptodate state, NFS would have it locked, and anyone else trying to get at it would sleep. This page we have currently is "dummy" in that it is only a place holder in case we don't get a full page from the networking. We have all the infrastructure to do everything up to this point. Next, if the networking gave us a full page, we'd "replace" the dummy page with this one, which would involve: 1) delete the dummy page from the lookup, insert the networking's page 2) arrange so that all sleepers on the dummy page will do a relookup and find the new page And when we're done with the operation we wake everyone up. I can't see any part of this turning out to be expensive.