Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755067Ab0HDEev (ORCPT ); Wed, 4 Aug 2010 00:34:51 -0400 Received: from smtp-out.google.com ([74.125.121.35]:27016 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753249Ab0HDEeu (ORCPT ); Wed, 4 Aug 2010 00:34:50 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:x-system-of-record; b=fUwKD0CBzswPSJj3aXENMjRhesJj/jbVDIXJJ9xucNd8w3Wxca1Q+kQ9YgtkL+Ijs RV/FXMv1CRZF/4tjkENZQ== MIME-Version: 1.0 In-Reply-To: <20100804043328.GB11950@ghc17.ghc.andrew.cmu.edu> References: <20100730235649.GA22644@ghc17.ghc.andrew.cmu.edu> <20100730235754.GB22644@ghc17.ghc.andrew.cmu.edu> <20100804043328.GB11950@ghc17.ghc.andrew.cmu.edu> Date: Tue, 3 Aug 2010 21:34:22 -0700 Message-ID: Subject: Re: [PATCH v4 1/2] cgroups: read-write lock CLONE_THREAD forking per threadgroup From: Paul Menage To: Ben Blum Cc: Andrew Morton , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, ebiederm@xmission.com, lizf@cn.fujitsu.com, matthltc@us.ibm.com, oleg@redhat.com Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1000 Lines: 20 On Tue, Aug 3, 2010 at 9:33 PM, Ben Blum wrote: >> As far as the #ifdef mess goes, it's true that some people don't have >> CONFIG_CGROUPS defined. I'd imagine that these are likely to be >> embedded systems with a fairly small number of processes and threads >> per process. Are there really any such platforms where the cost of a >> single extra rwsem per process is going to make a difference either in >> terms of memory or lock contention? I think you should consider making >> these additions unconditional. > > That's certainly an option, but I think it would be clean enough to put > static inline functions just under the signal_struct definition. Either sounds fine to me. I suspect others have a stronger opinion. Paul -- 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/