Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751347AbWARG3t (ORCPT ); Wed, 18 Jan 2006 01:29:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751351AbWARG3t (ORCPT ); Wed, 18 Jan 2006 01:29:49 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.145]:6558 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751347AbWARG3s (ORCPT ); Wed, 18 Jan 2006 01:29:48 -0500 Date: Tue, 17 Jan 2006 22:29:43 -0800 From: "Paul E. McKenney" To: Lee Revell Cc: Keith Owens , John Hesterberg , Matt Helsley , Jes Sorensen , Shailabh Nagar , Andrew Morton , Jay Lan , LKML , elsa-devel@lists.sourceforge.net, lse-tech@lists.sourceforge.net, CKRM-Tech , Paul Jackson , Erik Jacobson , Jack Steiner Subject: Re: [Lse-tech] Re: [ckrm-tech] Re: [PATCH 00/01] Move Exit Connectors Message-ID: <20060118062943.GC10765@us.ibm.com> Reply-To: paulmck@us.ibm.com References: <20060117172617.GA9283@us.ibm.com> <22822.1137542267@ocs3.ocs.com.au> <20060118024948.GA10407@us.ibm.com> <1137552907.3587.49.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1137552907.3587.49.camel@mindpipe> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1440 Lines: 30 On Tue, Jan 17, 2006 at 09:55:06PM -0500, Lee Revell wrote: > On Tue, 2006-01-17 at 18:49 -0800, Paul E. McKenney wrote: > > - * softirq handlers will have completed, since in some kernels > > + * softirq handlers will have completed, since in some kernels, these > > + * handlers can run in process context, and can block. > > * > > I was under the impression that softirq handlers can run in process > context in all kernels. Specifically, in realtime variants softirqs > always run in process context, and in mainline this only happens under > high load. We might be talking past each other on this one. If I am not getting too confused, it is possible to configure a mainline kernel so that the load cannot rise high enough to force softirqs into process context. Although looking at 2.6.15, it appears that this would require rebuilding after hand-editing the value of MAX_SOFTIRQ_RESTART, which some might feel too-brutal of tweaking to be considered mere "configuration". In any case, the key point of the comment is that synchronize_sched() is not guaranteed to wait for all pending softirq handlers to complete. Does the comment make that sufficiently clear? Thanx, Paul - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/