From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 215C0C67863 for ; Sat, 20 Oct 2018 04:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C342D2098A for ; Sat, 20 Oct 2018 04:59:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C342D2098A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ZenIV.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727017AbeJTNIn (ORCPT ); Sat, 20 Oct 2018 09:08:43 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:46054 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbeJTNIn (ORCPT ); Sat, 20 Oct 2018 09:08:43 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gDjML-0006Mt-S3; Sat, 20 Oct 2018 04:59:33 +0000 Date: Sat, 20 Oct 2018 05:59:33 +0100 From: Al Viro To: David Howells Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 02/24] iov_iter: Renumber the ITER_* constants in uio.h Message-ID: <20181020045933.GI32577@ZenIV.linux.org.uk> References: <153999783767.866.7957078562330181644.stgit@warthog.procyon.org.uk> <153999785247.866.991476712548092023.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153999785247.866.991476712548092023.stgit@warthog.procyon.org.uk> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 20, 2018 at 02:10:52AM +0100, David Howells wrote: > Renumber the ITER_* constants in uio.h to be contiguous to make comparing > them more efficient in a switch-statement. Are you sure that they *are* more efficient that way? Some of those paths are fairly hot, so much that I would really like to see profiles before and after these changes (both this and the previous one).