From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757235AbXFPVwa (ORCPT ); Sat, 16 Jun 2007 17:52:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751252AbXFPVwW (ORCPT ); Sat, 16 Jun 2007 17:52:22 -0400 Received: from nat0.xsigo.com ([216.184.48.10]:30108 "HELO main.xsigo.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S1750723AbXFPVwW (ORCPT ); Sat, 16 Jun 2007 17:52:22 -0400 Subject: need help with kmap_atomic() behavior From: Hari Hara Kumar M Reply-To: hari@xsigo.com To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org In-Reply-To: <463796B1.9060706@student.ltu.se> References: <20070501180113.20160.77978.sendpatchset@thinktank.campus.ltu.se> <1178044924.4320.29.camel@mulgrave.il.steeleye.com> <463796B1.9060706@student.ltu.se> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Sat, 16 Jun 2007 14:52:21 -0700 Message-Id: <1182030741.26268.59.camel@hmaharaj-ws.xsigo.com> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-27) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello We are mapping struct page ptrs from scattergather list entries using kmap_atomic(page_ptr, KM_USER0) to get the virtual address for doing a copy to work around some alignment restrictions in our driver. If the first entry in the scatterlist has length > 4k (say 11k) and has an offset of 1k then, will kmap of the struct page ptr in this scattergather entry map all of the relevant pages (3 in this case for 11k) needed to cover this sg entry? Thanks in advance. -Hari