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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 35C9CC43610 for ; Mon, 12 Nov 2018 21:45:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2DB92245E for ; Mon, 12 Nov 2018 21:45:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E2DB92245E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com 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 S1730579AbeKMHkW (ORCPT ); Tue, 13 Nov 2018 02:40:22 -0500 Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:11109 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725817AbeKMHkV (ORCPT ); Tue, 13 Nov 2018 02:40:21 -0500 Received: from ppp59-167-129-252.static.internode.on.net (HELO dastard) ([59.167.129.252]) by ipmail07.adl2.internode.on.net with ESMTP; 13 Nov 2018 08:15:17 +1030 Received: from dave by dastard with local (Exim 4.80) (envelope-from ) id 1gMK1D-0007Tx-S8; Tue, 13 Nov 2018 08:45:15 +1100 Date: Tue, 13 Nov 2018 08:45:15 +1100 From: Dave Chinner To: Eric Sandeen Cc: Joe Perches , "Darrick J. Wong" , Christoph Hellwig , linux-xfs@vger.kernel.org, LKML Subject: Re: [PATCH] xfs: Remove noinline from #define STATIC Message-ID: <20181112214515.GN19305@dastard> References: <7302f4a13c1cbf62b07f636878ce25fcca84b6c4.camel@perches.com> <6420cf91-89c8-a876-7a0d-25ab8ba428b8@sandeen.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6420cf91-89c8-a876-7a0d-25ab8ba428b8@sandeen.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 12, 2018 at 02:12:08PM -0600, Eric Sandeen wrote: > On 11/10/18 7:21 PM, Joe Perches wrote: > > Reduce total object size quite a bit (~32KB) and presumably > > improve performance at the same time. > > > > Total object size old vs new (x86-64 defconfig with xfs) > > > > text data bss dec hex filename > > - 959351 165573 632 1125556 112cb4 (TOTALS) (old) > > + 924683 165669 632 1090984 10a5a8 (TOTALS) (new) > > And what does it do to maximum stack excursions? Better yet: what does it do to corruption stack traces and debugging tools like profiling traces? i.e. this noinline directive isn't about stack usage, this is about being able to debug production code. Basically the compiler inliner is so agressive on static functions that it makes it impossible to decipher the stack traces. It flattens them way too much to be able to tell how we got to a specific location in the code. In reality, being able to find problems quickly and efficiently is far more important to us than being able to run everything at ludicrous speed.... Cheers, Dave. -- Dave Chinner david@fromorbit.com