From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Mackall Subject: Re: [Ksummit-2005-discuss] Summary of 2005 Kernel Summit Proposed Topics Date: Tue, 29 Mar 2005 15:25:45 -0800 Message-ID: <20050329232545.GL15453@waste.org> References: <1111905181.4753.15.camel@mylaptop> <20050326224621.61f6d917.davem@davemloft.net> <1112027284.5531.27.camel@mulgrave> <20050329152008.GD63268@muc.de> <1112116762.5088.65.camel@beastie> <1112130512.1077.107.camel@jzny.localdomain> <1112137210.1088.17.camel@jzny.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Rik van Riel , Dmitry Yusupov , Andi Kleen , James Bottomley , andrea@suse.de, michaelc@cs.wisc.edu, open-iscsi@googlegroups.com, ksummit-2005-discuss@thunk.org, netdev Return-path: To: jamal Content-Disposition: inline In-Reply-To: <1112137210.1088.17.camel@jzny.localdomain> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Tue, Mar 29, 2005 at 06:00:11PM -0500, jamal wrote: > On Tue, 2005-03-29 at 17:00, Rik van Riel wrote: > > > However, we often will need > > to get the packets off the network card before we can decide > > whether or not they're high priority. > > True - although one could argue that with NAPI that decision would be a > few opcodes away if you install the ingress qdisc. > So you may end up allocing only to free a few cycles later. Increased > memory traffic but the discard happens sufficiently early for a s/ware > only solution and CPU cycles not burnt as much. [...] I think we first need a software solution that makes no special assumptions about hardware capabilities. > > Also, there can be multiple high priority sockets, and we > > need to ensure they all make progress. Hence the mempool > > idea. > > Sorry missed the early part of this thread: mempool is some > strict priority scheme for mem allocation? A mempool is a private allocation pool that attempts to maintain a reserve of N objects. Various users in the kernel already. See mm/mempool.c. > For Sockets: If there was a "control" arbitrator preferably in user > space which would install - after a socket open - both network ingress > and/or egress rules for prioritization then wouldnt that suffice? Generally, we don't want any special handling except when we're effectively OOM. -- Mathematics is the supreme nostalgia of our time.