Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757123AbZJLPbL (ORCPT ); Mon, 12 Oct 2009 11:31:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755446AbZJLPbK (ORCPT ); Mon, 12 Oct 2009 11:31:10 -0400 Received: from smtp2.ultrahosting.com ([74.213.174.253]:54396 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752982AbZJLPbJ (ORCPT ); Mon, 12 Oct 2009 11:31:09 -0400 Date: Mon, 12 Oct 2009 11:23:23 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Mathieu Desnoyers cc: Peter Zijlstra , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Pekka Enberg , Tejun Heo , Mel Gorman , mingo@elte.hu Subject: Re: [this_cpu_xx V5 19/19] SLUB: Experimental new fastpath w/o interrupt disable In-Reply-To: <20091012152627.GA27835@Krystal> Message-ID: References: <1254988350.26976.256.camel@twins> <20091008171750.GA3370@Krystal> <20091008191754.GA12729@Krystal> <20091008203724.GA15798@Krystal> <20091012135600.GB15605@Krystal> <20091012152627.GA27835@Krystal> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 646 Lines: 29 On Mon, 12 Oct 2009, Mathieu Desnoyers wrote: > > If I just enable interrupts there then the preempt check will not be > > done and we may miss a scheduling point. > > > > That's why you should do: > > local_irq_save() > preempt_enable_no_resched() > ... > local_irq_restore() > preempt_check_resched() What is the difference then to local_irq_save() ... local_irq_enable(); preempt_enable(); ? -- 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/