From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [dm-devel] [PATCH 2/3] Introduce percpu rw semaphores Date: Mon, 30 Jul 2012 10:00:13 -0700 Message-ID: <20120730170013.GA4778@linux.vnet.ibm.com> References: <20120628111541.GB17515@quack.suse.cz> <1343508252.2626.13184.camel@edumazet-glaptop> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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" To: Mikulas Patocka Return-path: Received: from e7.ny.us.ibm.com ([32.97.182.137]:44300 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753631Ab2G3RAr (ORCPT ); Mon, 30 Jul 2012 13:00:47 -0400 Received: from /spool/local by e7.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 30 Jul 2012 13:00:45 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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