Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757168AbXETTB4 (ORCPT ); Sun, 20 May 2007 15:01:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755065AbXETTBt (ORCPT ); Sun, 20 May 2007 15:01:49 -0400 Received: from nz-out-0506.google.com ([64.233.162.224]:56120 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754540AbXETTBs (ORCPT ); Sun, 20 May 2007 15:01:48 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=bJFjblScLabT7wCrF/W0cp9k68ux+U1x9FtWnwAGTEQFDkKYHIT7+QdWaQildS0bcdKKWbPP8hF3oYxtkSelMAYXEtqoUJdbRhKcy1wjU2ST+kWHFRuLP9LNymL+brhq1gHu7CWK4ziftgNXC5Zn2PJ8/kazQdiCkAXYGYSiod8= Message-ID: Date: Sun, 20 May 2007 12:01:47 -0700 From: "Ulrich Drepper" To: "Eric Dumazet" Subject: Re: first little problem with private futexes Cc: "Ulrich Drepper" , "Linux Kernel" , "Andrew Morton" In-Reply-To: <46509924.8020904@cosmosbay.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <465095E5.4050508@redhat.com> <46509924.8020904@cosmosbay.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1021 Lines: 21 On 5/20/07, Eric Dumazet wrote: > > 1. do nothing, always use the shared futexes. Not very attractive IMO > > Why do you find this non attractive ? > > How is it performance critical ? You should know better than any other that the problem is not that the problem itself is the only one affected. If threads terminate all other programs and threads are affected since the global locks for the shared futexes are needed. That's the case I'm concerned about. It's not really about a single app creating many many threads over and over again. It's about many apps which do use threads (and that number will have to rise) starts and stop threads at a reasonable rate. It's just one more unnecessary point of contact between concurrently running apps. - 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/