From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hrndva-omtalb.mail.rr.com (hrndva-omtalb.mail.rr.com [71.74.56.123]) by ozlabs.org (Postfix) with ESMTP id 61E03DDF90 for ; Tue, 12 May 2009 22:36:08 +1000 (EST) Date: Tue, 12 May 2009 08:20:51 -0400 (EDT) From: Steven Rostedt To: Peter Zijlstra Subject: Re: question about softirqs In-Reply-To: <1242120761.11251.324.camel@twins> Message-ID: References: <18948.63755.279732.294842@cargo.ozlabs.ibm.com> <20090508.234815.127227651.davem@davemloft.net> <4A086DB2.8040703@nortel.com> <20090511.162436.193717082.davem@davemloft.net> <4A08C62F.1050105@nortel.com> <20090512081237.GA16403@elte.hu> <1242119578.11251.321.camel@twins> <20090512092348.GA29796@elte.hu> <1242120761.11251.324.camel@twins> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: netdev@vger.kernel.org, David Miller , linuxppc-dev@ozlabs.org, paulus@samba.org, Ingo Molnar , Thomas Gleixner List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 12 May 2009, Peter Zijlstra wrote: > On Tue, 2009-05-12 at 11:23 +0200, Ingo Molnar wrote: > > > > Yeah, that would be "nice". A single IRQ thread plus the process > > context(s) doing networking might perform well. > > > > Multiple IRQ threads (softirq and hardirq threads mixed) i'm not so > > sure about - it's extra context-switching cost. > > Sure, that was implied by the getting rid of softirqs ;-), on -rt we > currently suffer this hardirq/softirq thread ping-pong, it sucks. I'm going to be playing around with bypassing the net-rx/tx with my network drivers. I'm going to add threaded irqs for my network cards and have the driver threads do the work to get through the tcp/ip stack. I'll still keep the softirqs for other cards, but I want to see how fast it speeds things up if I have the driver thread do it. -- Steve