From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753479Ab2GaABQ (ORCPT ); Mon, 30 Jul 2012 20:01:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:24817 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753000Ab2GaABI (ORCPT ); Mon, 30 Jul 2012 20:01:08 -0400 Date: Mon, 30 Jul 2012 20:00:19 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file.rdu.redhat.com To: "Paul E. McKenney" cc: Eric Dumazet , Jens Axboe , Andrea Arcangeli , Jan Kara , dm-devel@redhat.com, linux-kernel@vger.kernel.org, Jeff Moyer , Alexander Viro , kosaki.motohiro@jp.fujitsu.com, linux-fsdevel@vger.kernel.org, lwoodman@redhat.com, "Alasdair G. Kergon" Subject: Re: [dm-devel] [PATCH 2/3] Introduce percpu rw semaphores In-Reply-To: <20120730170013.GA4778@linux.vnet.ibm.com> Message-ID: References: <20120628111541.GB17515@quack.suse.cz> <1343508252.2626.13184.camel@edumazet-glaptop> <20120730170013.GA4778@linux.vnet.ibm.com> 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 On Mon, 30 Jul 2012, Paul E. McKenney wrote: > On Sun, Jul 29, 2012 at 01:13:34AM -0400, Mikulas Patocka wrote: > > On Sat, 28 Jul 2012, Eric Dumazet wrote: > > > On Sat, 2012-07-28 at 12:41 -0400, Mikulas Patocka wrote: > > [ . . . ] > > > > (bdev->bd_block_size should be read exactly once ) > > > > Rewrite all direct and non-direct io code so that it reads block size just > > once ... > > For whatever it is worth, the 3.5 Linux kernel only has about ten mentions > of bd_block_size, at least according to cscope. > > Thanx, Paul plus 213 uses of i_blkbits (which is derived directly from bd_block_size). 45 of them is in fs/*.c and mm/*.c Mikulas