Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754568Ab0BVWBF (ORCPT ); Mon, 22 Feb 2010 17:01:05 -0500 Received: from smtp-out.google.com ([216.239.33.17]:35619 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754476Ab0BVWBB (ORCPT ); Mon, 22 Feb 2010 17:01:01 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=Oc2EWr5/chBb3jnOYnb6MOdp2+W6QDB/ApgfCl7ev5qTl0Yq8piX7tUKDwnPjnV3u IW+eU/W9ylXnSUhrhxfcw== Date: Mon, 22 Feb 2010 14:00:52 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Nick Piggin cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Miao Xie , Lee Schermerhorn Subject: Re: [regression] cpuset,mm: update tasks' mems_allowed in time (58568d2) In-Reply-To: <20100222121222.GV9738@laptop> Message-ID: References: <20100218134921.GF9738@laptop> <20100219033126.GI9738@laptop> <20100222121222.GV9738@laptop> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 693 Lines: 15 On Mon, 22 Feb 2010, Nick Piggin wrote: > If you have a concurrent reader without any synchronisation, then what > stops it from loading a word of the mask before stores to add the new > nodes and then loading another word of the mask after the stores to > remove the old nodes? (which can give an empty mask). > Currently nothing, so we'll need a variant for configurations where the size of nodemask_t is larger than we can atomically store. -- 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/