From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: question about softirqs Date: Tue, 12 May 2009 22:28:48 -0700 (PDT) Message-ID: <20090512.222848.152842353.davem@davemloft.net> References: <20090512092348.GA29796@elte.hu> <20090512.214427.193728136.davem@davemloft.net> <18954.22390.754419.803434@cargo.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: mingo@elte.hu, a.p.zijlstra@chello.nl, cfriesen@nortel.com, tglx@linutronix.de, rostedt@goodmis.org, linuxppc-dev@ozlabs.org, netdev@vger.kernel.org To: paulus@samba.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:47226 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202AbZEMF2v (ORCPT ); Wed, 13 May 2009 01:28:51 -0400 In-Reply-To: <18954.22390.754419.803434@cargo.ozlabs.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Paul Mackerras Date: Wed, 13 May 2009 15:15:34 +1000 > David Miller writes: > >> I fully expected us to be, at this point, talking about putting the >> pending softirq check back into the trap return path :-/ > > Would that actually do any good, in the case where the system has > decided that ksoftirqd is handling soft irqs at the moment? Even if ksoftirqd is running, we check and run pending softirqs from trap return. Sure, I imagine we could re-enter this "ksoftirq blocked by highprio thread" situation if we get flooded every single time over and over again.