Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754784AbYFZGC0 (ORCPT ); Thu, 26 Jun 2008 02:02:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751586AbYFZGCS (ORCPT ); Thu, 26 Jun 2008 02:02:18 -0400 Received: from gir.skynet.ie ([193.1.99.77]:32888 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751467AbYFZGCS (ORCPT ); Thu, 26 Jun 2008 02:02:18 -0400 Date: Thu, 26 Jun 2008 07:02:15 +0100 (IST) From: Dave Airlie X-X-Sender: airlied@skynet.skynet.ie To: Jeremy Fitzhardinge cc: Keith Packard , Arjan van de Ven , Dave Airlie , linux-kernel Subject: Re: kmap_atomic_pfn for PCI BAR access? In-Reply-To: <48633057.1040106@goop.org> Message-ID: References: <1214242487.11887.35.camel@koto.keithp.com> <4862EE4C.4060009@goop.org> <21d7e9970806251823q3405e192q13d4944bd0cc3291@mail.gmail.com> <20080625213603.0e82805b@infradead.org> <1214458589.1044.45.camel@koto.keithp.com> <48633057.1040106@goop.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 578 Lines: 17 > > > > Anything that does any kind of pagetable manipulation needs to do tlb flushes. > kunmap_atomic handles the flushing. It doesn't however need to do an IPI dance which is the worst part of doing a tlb flush on SMP machines. flushing local CPU tlbs is bad, but doing IPIs and waiting for everyone else is brutal. Dave. -- 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/