Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751248Ab0AGRXN (ORCPT ); Thu, 7 Jan 2010 12:23:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750832Ab0AGRXM (ORCPT ); Thu, 7 Jan 2010 12:23:12 -0500 Received: from casper.infradead.org ([85.118.1.10]:58321 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750759Ab0AGRXM (ORCPT ); Thu, 7 Jan 2010 12:23:12 -0500 Subject: Re: [RFC][PATCH 6/8] mm: handle_speculative_fault() From: Peter Zijlstra To: Linus Torvalds Cc: Christoph Lameter , Arjan van de Ven , "Paul E. McKenney" , KAMEZAWA Hiroyuki , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "minchan.kim@gmail.com" , "hugh.dickins" , Nick Piggin , Ingo Molnar In-Reply-To: References: <20100104182429.833180340@chello.nl> <20100104182813.753545361@chello.nl> <20100105054536.44bf8002@infradead.org> <20100105192243.1d6b2213@infradead.org> Content-Type: text/plain; charset="UTF-8" Date: Thu, 07 Jan 2010 18:22:40 +0100 Message-ID: <1262884960.4049.106.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 750 Lines: 21 On Thu, 2010-01-07 at 08:19 -0800, Linus Torvalds wrote: > > So now some paths are indeed holding it for writing (or need to wait for > it to become writable). And the fairness of rwsems quite possibly then > impacts throughput a _lot_.. Right, supposing we can make this speculative fault stuff work, then we can basically reduce the mmap_sem usage in fault to: - allocating new page tables - extending the growable vmas And do everything else without holding it, including zeroing and IO. -- 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/