From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin LaHaise Subject: Re: [PATCH] change b_size to size_t Date: Thu, 23 Feb 2006 11:32:04 -0500 Message-ID: <20060223163204.GA27682@kvack.org> References: <1140470487.22756.12.camel@dyn9047017100.beaverton.ibm.com> <20060222151216.GA22946@lst.de> <1140627510.22756.81.camel@dyn9047017100.beaverton.ibm.com> <20060222165942.GA25167@lst.de> <20060223014004.GA900@frodo> <20060222175923.784ce5de.akpm@osdl.org> <1140712093.22756.106.camel@dyn9047017100.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Nathan Scott , christoph , mcao@us.ibm.com, lkml , linux-fsdevel Return-path: Received: from kanga.kvack.org ([66.96.29.28]:31213 "EHLO kanga.kvack.org") by vger.kernel.org with ESMTP id S1751435AbWBWQhM (ORCPT ); Thu, 23 Feb 2006 11:37:12 -0500 To: Badari Pulavarty Content-Disposition: inline In-Reply-To: <1140712093.22756.106.camel@dyn9047017100.beaverton.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Feb 23, 2006 at 08:28:12AM -0800, Badari Pulavarty wrote: > Here is the updated version of the patch, which changes > buffer_head.b_size to size_t to support mapping large > amount of disk blocks (for large IOs). Your patch doesn't seem to be inline, so I can't quote it. Several problems: on 64 bit platforms you introduced 4 bytes of padding into buffer_head. atomic_t only takes up 4 byte, while size_t is 8 byte aligned. This is a waste of memory, imo, seeing as the vast majority of systems out there will not be doing 4GB+ ios any time soon. Also, the cast to unsigned long long for size_t is pretty atrocious. Cast to unsigned long if anything, as size_t is unsigned long on all platforms linux runs on. -ben -- "Ladies and gentlemen, I'm sorry to interrupt, but the police are here and they've asked us to stop the party." Don't Email: .