From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752451AbbFYDgr (ORCPT ); Wed, 24 Jun 2015 23:36:47 -0400 Received: from www.sr71.net ([198.145.64.142]:44630 "EHLO blackbird.sr71.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751877AbbFYDgk (ORCPT ); Wed, 24 Jun 2015 23:36:40 -0400 Message-ID: <558B7746.9010605@sr71.net> Date: Wed, 24 Jun 2015 20:36:38 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 CC: mingo@redhat.com, peterz@infradead.org, linux-kernel@vger.kernel.org, dave.hansen@linux.intel.com Subject: Re: [RFC][PATCH] sched: might_sleep(): do rate-limiting before sanity checks References: <20150625000354.255E7263@viggo.jf.intel.com> In-Reply-To: <20150625000354.255E7263@viggo.jf.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/24/2015 05:03 PM, Dave Hansen wrote: > In any case, we ratelimit might_sleep() checks anyway. But, we > do the ratelimiting *after* we check the other conditions for > might_sleep() including the (costly) irqs_disabled() call. Thinking about this a bit more, this patch is wrong. This only does a _check_ once per jiffy instead of just one warning per jiffy, which is totally bogus. I would be interested, though, if anybody has any ideas about speeding up the irqs_disabled() checking.