From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [git patches] xfs and block fixes for virtually indexed arches Date: Thu, 17 Dec 2009 10:17:03 -0800 (PST) Message-ID: References: <20091216043618.GB9104@hera.kernel.org> <20091217132256.GO28962@bombadil.infradead.org> <20091217163036.GE2123@thunk.org> <20091217170743.GA10431@infradead.org> <20091217180802.GA1546@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20091217180802.GA1546@flint.arm.linux.org.uk> Sender: linux-parisc-owner@vger.kernel.org To: Russell King Cc: Christoph Hellwig , tytso@mit.edu, Kyle McMartin , linux-parisc@vger.kernel.org, Linux Kernel Mailing List , James.Bottomley@suse.de, linux-arch@vger.kernel.org, Jens Axboe List-Id: linux-arch.vger.kernel.org On Thu, 17 Dec 2009, Russell King wrote: > > That's not entirely true. If you have write back caches which are not DMA > coherent, you need to as a minimum: > > - on write, clean the cache to ensure that the page is up to date with data > held in cache. > > - on read, you must ensure that there are no potential write-backs before > the read commenses and invalidate at some point. Right you are. Linus From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:37674 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934997AbZLQSRf (ORCPT ); Thu, 17 Dec 2009 13:17:35 -0500 Date: Thu, 17 Dec 2009 10:17:03 -0800 (PST) From: Linus Torvalds Subject: Re: [git patches] xfs and block fixes for virtually indexed arches In-Reply-To: <20091217180802.GA1546@flint.arm.linux.org.uk> Message-ID: References: <20091216043618.GB9104@hera.kernel.org> <20091217132256.GO28962@bombadil.infradead.org> <20091217163036.GE2123@thunk.org> <20091217170743.GA10431@infradead.org> <20091217180802.GA1546@flint.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-arch-owner@vger.kernel.org List-ID: To: Russell King Cc: Christoph Hellwig , tytso@mit.edu, Kyle McMartin , linux-parisc@vger.kernel.org, Linux Kernel Mailing List , James.Bottomley@suse.de, linux-arch@vger.kernel.org, Jens Axboe Message-ID: <20091217181703.pXRPRnFuN3KdAPXthSFpknPep-X-DkkoZSvep3CMGWk@z> On Thu, 17 Dec 2009, Russell King wrote: > > That's not entirely true. If you have write back caches which are not DMA > coherent, you need to as a minimum: > > - on write, clean the cache to ensure that the page is up to date with data > held in cache. > > - on read, you must ensure that there are no potential write-backs before > the read commenses and invalidate at some point. Right you are. Linus