Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755987AbYHMNho (ORCPT ); Wed, 13 Aug 2008 09:37:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755491AbYHMNhd (ORCPT ); Wed, 13 Aug 2008 09:37:33 -0400 Received: from casper.infradead.org ([85.118.1.10]:49503 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755384AbYHMNhc (ORCPT ); Wed, 13 Aug 2008 09:37:32 -0400 Date: Wed, 13 Aug 2008 06:35:33 -0700 From: Arjan van de Ven To: Ingo Molnar Cc: Pardo , akpm@linux-foundation.org, hugh@veritas.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, briangrant@google.com, cgd@google.com, mbligh@google.com, Ulrich Drepper , Linus Torvalds , Thomas Gleixner , "H. Peter Anvin" Subject: Re: pthread_create() slow for many threads; also time to revisit 64b context switch optimization? Message-ID: <20080813063533.444c650d@infradead.org> In-Reply-To: <20080813104445.GA24632@elte.hu> References: <20080813104445.GA24632@elte.hu> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 985 Lines: 31 On Wed, 13 Aug 2008 12:44:45 +0200 Ingo Molnar wrote: > There are various other options to solve the (severe!) performance > breakdown: > > 1- glibc could start not using MAP_32BIT for 64-bit thread stacks > (the boxes where context-switching is slow probably do not matter all > that much anymore - they were very slow at everything 64-bit anyway) > > Pros: easiest solution. > Cons: slows down the affected machines and needs a new glibc. > > > i'd go for 1) or 2). I would go for 1) clearly; it's the cleanest thing going forward for sure. -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/