From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757940AbZBBUvG (ORCPT ); Mon, 2 Feb 2009 15:51:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753574AbZBBUuy (ORCPT ); Mon, 2 Feb 2009 15:50:54 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:35956 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753374AbZBBUux (ORCPT ); Mon, 2 Feb 2009 15:50:53 -0500 Subject: Re: hackbench [pthread mode] regression with 2.6.29-rc3 From: Peter Zijlstra To: Bryon Roche Cc: linux-kernel@vger.kernel.org In-Reply-To: References: <1233473426.2604.13.camel@ymzhang> <1233476961.13659.12.camel@minggr.sh.intel.com> <1233479836.4787.63.camel@laptop> <1233482239.4787.65.camel@laptop> <1233537134.2604.24.camel@ymzhang> <1233564818.4787.107.camel@laptop> Content-Type: text/plain Date: Mon, 02 Feb 2009 21:50:48 +0100 Message-Id: <1233607848.10184.14.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2009-02-02 at 17:49 +0000, Bryon Roche wrote: don't drop CCs > On Mon, 02 Feb 2009 09:53:38 +0100, Peter Zijlstra wrote: > > > On Mon, 2009-02-02 at 09:12 +0800, Zhang, Yanmin wrote: > > > > I would rather go back to the old model where we iterate all threads, > > and find a way to not make programs with too many threads for their own > > good lock up the kernel, but instead get poor service. > > Now, there's an interesting question, what is the definition of too many > threads for a program's own good? When evaluating this, please assume > that you > do actually have enough RAM to keep thread stacks/other userspace > threading > resources in-core. In my book a program has too many threads when it outnumbers the number of cpus available to it by an order of so.