From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753219AbYL3L1X (ORCPT ); Tue, 30 Dec 2008 06:27:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751530AbYL3L1O (ORCPT ); Tue, 30 Dec 2008 06:27:14 -0500 Received: from gw.goop.org ([64.81.55.164]:49803 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751510AbYL3L1O (ORCPT ); Tue, 30 Dec 2008 06:27:14 -0500 Message-ID: <495A058C.7060105@goop.org> Date: Tue, 30 Dec 2008 22:27:08 +1100 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.18 (X11/20081119) MIME-Version: 1.0 To: Nick Piggin CC: Andrew Morton , Linux Kernel Mailing List , Linux Memory Management List , the arch/x86 maintainers , Arjan van de Ven Subject: Re: [PATCH RFC] vm_unmap_aliases: allow callers to inhibit TLB flush References: <49416494.6040009@goop.org> <200707241140.12945.nickpiggin@yahoo.com.au> <49470433.4050504@goop.org> <200812301442.37654.nickpiggin@yahoo.com.au> In-Reply-To: <200812301442.37654.nickpiggin@yahoo.com.au> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nick Piggin wrote: > I have patches to move the tlb flushing to an asynchronous process context... > but all tweaks to that (including flushing at vmap) are just variations on the > existing flushing scheme and don't solve your problem, so I don't think we > really need to change that for the moment (my patches are mainly for latency > improvement and to allow vunmap to be usable from interrupt context). > Well, that's basically what I want - I want to use vunmap in an interrupts-disabled context. Any other possibility of deferring tlb flushes is pure bonus and not all that important. But it also occurred to me that Xen doesn't use IPIs for cross-cpu TLB flushes (it goes to hypercall), so it shouldn't be an issue anyway. I haven't had a chance to look at what's really going on there. J