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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 F107FC43610 for ; Mon, 12 Nov 2018 22:30:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC130223DD for ; Mon, 12 Nov 2018 22:30:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BC130223DD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.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 S1730657AbeKMIZR (ORCPT ); Tue, 13 Nov 2018 03:25:17 -0500 Received: from smtprelay0164.hostedemail.com ([216.40.44.164]:43755 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728030AbeKMIZR (ORCPT ); Tue, 13 Nov 2018 03:25:17 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay01.hostedemail.com (Postfix) with ESMTP id 0579D100E86D4; Mon, 12 Nov 2018 22:30:06 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: beast30_74ed5e0c58a5f X-Filterd-Recvd-Size: 2375 Received: from XPS-9350 (unknown [172.58.27.5]) (Authenticated sender: joe@perches.com) by omf18.hostedemail.com (Postfix) with ESMTPA; Mon, 12 Nov 2018 22:30:03 +0000 (UTC) Message-ID: Subject: Re: [PATCH] xfs: Remove noinline from #define STATIC From: Joe Perches To: Dave Chinner , Eric Sandeen Cc: "Darrick J. Wong" , Christoph Hellwig , linux-xfs@vger.kernel.org, LKML Date: Mon, 12 Nov 2018 14:30:01 -0800 In-Reply-To: <20181112214515.GN19305@dastard> References: <7302f4a13c1cbf62b07f636878ce25fcca84b6c4.camel@perches.com> <6420cf91-89c8-a876-7a0d-25ab8ba428b8@sandeen.net> <20181112214515.GN19305@dastard> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.30.1-1build1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-11-13 at 08:45 +1100, Dave Chinner wrote: > 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.... Is that really a compelling argument given thw ~50:50 split of static/STATIC uses in xfs? $ git grep -w STATIC fs/xfs/ | wc -l 1064 $ git grep -w static fs/xfs/ | wc -l 942