Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759024AbZCWPWZ (ORCPT ); Mon, 23 Mar 2009 11:22:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759036AbZCWPV4 (ORCPT ); Mon, 23 Mar 2009 11:21:56 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:37735 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759029AbZCWPVz (ORCPT ); Mon, 23 Mar 2009 11:21:55 -0400 Date: Mon, 23 Mar 2009 16:19:54 +0100 From: Ingo Molnar To: Miklos Szeredi Cc: linux-kernel@vger.kernel.org, oleg@redhat.com, peterz@infradead.org, roland@redhat.com, efault@gmx.de, rjw@sisk.pl, jdike@addtoit.com, user-mode-linux-devel@lists.sourceforge.net, torvalds@linux-foundation.org, akpm@linux-foundation.org, stable@kernel.org Subject: Re: [patch] fix ptrace slowness Message-ID: <20090323151954.GC21267@elte.hu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 957 Lines: 31 * Miklos Szeredi wrote: > This one incorporates comments from Oleg and Ingo. Please apply > to 2.6.29 and 2.6.2[78]-stable trees. The fix first needs to go upstream. There's an alternative patch below. Would you mind to give it a test? Chances are that it will make UML even faster than your fix. Ingo diff --git a/kernel/sched.c b/kernel/sched.c index 3e827b8..2d60f23 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2119,7 +2119,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state) * yield - it could be a while. */ if (unlikely(on_rq)) { - schedule_timeout_uninterruptible(1); + cpu_relax(); + cond_resched(); continue; } -- 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/