From: Jeff Layton Subject: Re: [PATCH] sunrpc: make warning in svc_check_conn_limits() more generic Date: Wed, 15 Oct 2008 20:51:18 -0400 Message-ID: <20081015205118.14de4611@tleilax.poochiereds.net> References: <1221225127-6042-1-git-send-email-jlayton@redhat.com> <20080924215742.GG10841@fieldses.org> <20080925162315.6f29d092@tleilax.poochiereds.net> <20081015081457.56ef3778@tleilax.poochiereds.net> <20081015202102.GC5038@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linux-nfs@vger.kernel.org, neilb@suse.de To: "J. Bruce Fields" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:50488 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348AbYJPAwG (ORCPT ); Wed, 15 Oct 2008 20:52:06 -0400 In-Reply-To: <20081015202102.GC5038@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, 15 Oct 2008 16:21:02 -0400 "J. Bruce Fields" wrote: > On Wed, Oct 15, 2008 at 08:14:57AM -0400, Jeff Layton wrote: > > From the descriptions in those commits, it looks like the check > > in svc_check_conn_limits was intended to prevent messages from too > > many sockets overloading the receive buffers. > > Aren't the receive buffers per-connection? > > --b. > Oof...you're quite right. I misunderstood the code earlier. Thinking this through a bit more... I suppose the main worry is that we have a service with too few threads and a ton of sockets. We end up in a situation where the receive buffers aren't getting processed quickly enough and connections start stalling out. I suppose the only real remedy for that is to increase the number of threads, but that's not an option for services like lockd. So maybe ignoring this check on single-threaded services is the way to go after all? I don't see a way to make this auto-tuning based on memory since that doesn't seem to be what the check is intended to help... -- Jeff Layton