Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966127Ab0GPTaw (ORCPT ); Fri, 16 Jul 2010 15:30:52 -0400 Received: from terminus.zytor.com ([198.137.202.10]:37568 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966044Ab0GPTav (ORCPT ); Fri, 16 Jul 2010 15:30:51 -0400 Message-ID: <4C40B324.4040907@zytor.com> Date: Fri, 16 Jul 2010 12:29:40 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.10) Gecko/20100621 Fedora/3.0.5-1.fc13 Thunderbird/3.0.5 MIME-Version: 1.0 To: Avi Kivity CC: Mathieu Desnoyers , LKML , Linus Torvalds , Andrew Morton , Ingo Molnar , Peter Zijlstra , Steven Rostedt , Steven Rostedt , Frederic Weisbecker , Thomas Gleixner , Christoph Hellwig , Li Zefan , Lai Jiangshan , Johannes Berg , Masami Hiramatsu , Arnaldo Carvalho de Melo , Tom Zanussi , KOSAKI Motohiro , Andi Kleen , akpm@osdl.org, Jeremy Fitzhardinge , "Frank Ch. Eigler" Subject: Re: [patch 2/2] x86 NMI-safe INT3 and Page Fault References: <20100714154923.947138065@efficios.com> <20100714155804.252253097@efficios.com> <4C405078.20707@redhat.com> <20100716144927.GA22516@Krystal> <4C408D0C.5050709@redhat.com> <20100716165855.GA3836@Krystal> <4C409CBA.1050709@redhat.com> <4C409F62.6030303@zytor.com> <4C40A1BD.4040507@redhat.com> <20100716182240.GA23215@Krystal> <4C40A5A0.3010107@redhat.com> In-Reply-To: <4C40A5A0.3010107@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 698 Lines: 18 On 07/16/2010 11:32 AM, Avi Kivity wrote: > > How long would vmalloc_sync_all take with a few thousand mm_struct take? > > We share the pmds, yes? So it's a few thousand memory accesses. The > direct impact is probably negligible, compared to actually loading the > module from disk. All we need is to make sure the locking doesn't slow > down unrelated stuff. > It's not the memory accesses, it's the need to synchronize all the CPUs. -hpa -- 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/