From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756151Ab0IHQvv (ORCPT ); Wed, 8 Sep 2010 12:51:51 -0400 Received: from ns2.cypress.com ([157.95.67.5]:40984 "EHLO ns2.cypress.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753512Ab0IHQvs (ORCPT ); Wed, 8 Sep 2010 12:51:48 -0400 Reply-To: From: "David Cross" To: Cc: , , References: <1283888011.7250.17.camel@odc-laptop> <4313.1283956531@redhat.com> Subject: RE: [PATCH] Cachefiles, mpage_cleardirty addtition, west bridge related Date: Wed, 8 Sep 2010 09:51:22 -0700 Organization: Cypress Semiconductor Message-ID: <9465F8A421744836B35704023ECA8253@stanford.edu> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 Thread-Index: ActPYx0sJldoARoJRmyiY0nqvPZdswAEntqQ X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-Reply-To: <4313.1283956531@redhat.com> X-Brightmail-Tracker: AAAAAA== X-Brightmail-Tracker: AAAAAA== X-MailScanner: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: dhowells@redhat.com [mailto:dhowells@redhat.com] > David Cross wrote: > > This patch adds the mpage_cleardirty function to the cachefiles > implementation in the kernel. > Ummm... How is this used by cachefiles? Nothing in this patch actually > uses > mpage_cleardirty(). This is used by the current west bridge driver in the linux-next tree, marked as BROKEN at the moment. It is used in order to clear dirty pages from the page cache for a specific file after it has been allocated. This allows west bridge to transfer data from USB to storage directly without requiring that the file data path go through the CPU. The easiest way to think of this is that it allows for direct file based DMA. Please let me know if you have any additional questions or concerns on this. Thanks, David --------------------------------------------------------------- This message and any attachments may contain Cypress (or its subsidiaries) confidential information. If it has been received in error, please advise the sender and immediately delete this message. ---------------------------------------------------------------