Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756306Ab3IEEUH (ORCPT ); Thu, 5 Sep 2013 00:20:07 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:58741 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753365Ab3IEEUD (ORCPT ); Thu, 5 Sep 2013 00:20:03 -0400 Date: Thu, 5 Sep 2013 05:20:00 +0100 From: Al Viro To: Linus Torvalds Cc: Waiman Long , Scott J Norton , linux-fsdevel , "Chandramouleeswaran, Aswin" , Linux Kernel Mailing List Subject: Re: [PATCH] dcache: Translating dentry into pathname without taking rename_lock Message-ID: <20130905041959.GN13318@ZenIV.linux.org.uk> References: <1378321523-40893-1-git-send-email-Waiman.Long@hp.com> <20130904191104.GK13318@ZenIV.linux.org.uk> <5227E321.4090008@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 864 Lines: 19 On Wed, Sep 04, 2013 at 07:48:14PM -0700, Linus Torvalds wrote: > - use the name length as a maximum > > - do a byte-at-a-time copy, stopping at a zero (it's going to be > faster than memchr anyway) > > Then, later on, we can do one that does a word-at-a-time using the > CONFIG_DCACHE_WORD_ACCESS magic: we know dentry names are always > word-aligned, and we have an efficient "has_zero()" function for > finding zero bytes in a word. Umm... Dentry names are word-aligned, but the place where we copy them doesn't have to be. OTOH, DCACHE_WORD_ACCESS is for architectures where unaligned stores are fine, so... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/