Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762005AbYGCNMF (ORCPT ); Thu, 3 Jul 2008 09:12:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755239AbYGCNLw (ORCPT ); Thu, 3 Jul 2008 09:11:52 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:44741 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753499AbYGCNLv (ORCPT ); Thu, 3 Jul 2008 09:11:51 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: benh@kernel.crashing.org Cc: James Bottomley , ksummit-2008-discuss@lists.linux-foundation.org, Linux Kernel list , Jeremy Kerr References: <1214916335.20711.141.camel@pasglop> <486B0298.5030508@linux.intel.com> <1214977447.21182.33.camel@pasglop> <1215007896.3330.6.camel@localhost.localdomain> <1215032409.21182.56.camel@pasglop> Date: Thu, 03 Jul 2008 03:12:51 -0700 In-Reply-To: <1215032409.21182.56.camel@pasglop> (Benjamin Herrenschmidt's message of "Thu, 03 Jul 2008 07:00:09 +1000") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SA-Exim-Connect-IP: 24.130.11.59 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;benh@kernel.crashing.org X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.7 BAYES_20 BODY: Bayesian spam probability is 5 to 20% * [score: 0.0507] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 XM_SPF_Neutral SPF-Neutral Subject: Re: [Ksummit-2008-discuss] Delayed interrupt work, thread pools X-SA-Exim-Version: 4.2 (built Thu, 03 Mar 2005 10:44:12 +0100) X-SA-Exim-Scanned: Yes (on mgr1.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 893 Lines: 19 Benjamin Herrenschmidt writes: > The question is: is that significantly less overhead than just spawning > a new full blown kernel thread ? enough to justify the complexity ? at > the end of the day, it means allocating a stack (which on ppc64 is still > 16K, I know it sucks)... I looked at this a while ago. And right now kernel_thread is fairly light. kthread_create has latency issues because we need to queue up a task on our kernel thread spawning daemon, and let it fork the child. Needing to go via the kthread spawning daemon didn't look fundamental, just something that was a challenge to sort out. Eric -- 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/