From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH]: was Re: LLTX and netif_stop_queue Date: Thu, 27 Jan 2005 09:26:18 +0100 Message-ID: <20050127082618.GE2731@wotan.suse.de> References: <20050119164640.6c67bdfa.davem@davemloft.net> <52r7kgu5n5.fsf@topspin.com> <20050119230526.393a5184.davem@davemloft.net> <20050120085611.33f9485e@dxpl.pdx.osdl.net> <20050121105452.GA12988@xi.wantstofly.org> <20050125222705.1ee878fd.davem@davemloft.net> <20050126132512.GA18220@xi.wantstofly.org> <20050126223247.3e4643cc.davem@davemloft.net> <20050127071645.GA2731@wotan.suse.de> <20050126232227.3ce4decb.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andi Kleen , buytenh@wantstofly.org, shemminger@osdl.org, roland@topspin.com, hadi@cyberus.ca, iod00d@hp.com, eric.lemoine@gmail.com, netdev@oss.sgi.com, openib-general@openib.org, kaber@trash.net Return-path: To: "David S. Miller" Content-Disposition: inline In-Reply-To: <20050126232227.3ce4decb.davem@davemloft.net> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Wed, Jan 26, 2005 at 11:22:27PM -0800, David S. Miller wrote: > On Thu, 27 Jan 2005 08:16:45 +0100 > Andi Kleen wrote: > > > > Yes, that's the idea. > > > > per CPU only works in preemptive kernel if you have preemption > > disabled all the time. Do you? > > > > Seems not likely to me. > > BH is disabled in these code paths (specifically we're talking > about ->hard_start_xmit()), as that is where the recursion > check goes. Hmm, but hard_start_xmit is allowed to enable preemption again, isn't it? An safer alternative may be to change the cpu mask of the current process temporarily. -Andi