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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0CAA4ECAAA3 for ; Fri, 26 Aug 2022 04:16:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244476AbiHZEQa (ORCPT ); Fri, 26 Aug 2022 00:16:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244491AbiHZEQa (ORCPT ); Fri, 26 Aug 2022 00:16:30 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59BA0BB01B; Thu, 25 Aug 2022 21:16:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0FC77B82F5C; Fri, 26 Aug 2022 04:16:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92375C433C1; Fri, 26 Aug 2022 04:16:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661487386; bh=dWUP5SzBKFkPPFrG5kSA+6oPlRpqgdw42NE7/hoQ1Qg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MiTEg+idY8oPIckibp+T6MYEKDON0WivdR/932DAeaZTSHjcPqZZ6m8grGU6QywGI IaX+jY3R4IUpB7/4unSU8I/6n/nx88snyehJEKZcB5xsSt1m8MhYr2lU4ewqdYLMXv A7GuWyh2bpOeWyAA+TIsFiKl5FG2i+sS2wEkgpAFPZ0BYkXWUkXjnNp7wV32pvEpAT 6adymDIBYkqb4ycxpjaJXy42FBqdTeZTUTep08rEQoWQBfqZOYAaz2uIHvAUgIgLrX OR92z3HcoYRgavC0A6gjfQULOQ3ZgLOfstWQpG5+y64WVuj7cr/uiuSqqe0GC3nLtz bglc4YvtgzDjg== Date: Fri, 26 Aug 2022 07:16:12 +0300 From: Mike Rapoport To: Bagas Sanjaya Cc: Jonathan Corbet , Yixuan Cao , akpm@linux-foundation.org, yejiajian2018@email.szu.edu.cn, skhan@linuxfoundation.org, akiyks@gmail.com, zhangyinan2019@email.szu.edu.cn, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Documentation/mm/page_owner.rst: update experimental data Message-ID: References: <20220825172934.4344-1-caoyixuan2019@email.szu.edu.cn> <87ilmgyz34.fsf@meer.lwn.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, Aug 26, 2022 at 09:30:46AM +0700, Bagas Sanjaya wrote: > On Thu, Aug 25, 2022 at 12:09:35PM -0600, Jonathan Corbet wrote: > > > - Without page owner:: > > > > > > text data bss dec hex filename > > > - 48392 2333 644 51369 c8a9 mm/page_alloc.o > > > + 58581 3166 652 62399 f3bf mm/page_alloc.o > > > > > > - With page owner:: > > > > > > text data bss dec hex filename > > > - 48800 2445 644 51889 cab1 mm/page_alloc.o > > > - 6662 108 29 6799 1a8f mm/page_owner.o > > > - 1025 8 8 1041 411 mm/page_ext.o > > > + 59085 3294 652 63031 f637 mm/page_alloc.o > > > + 7464 125 28 7617 1dc1 mm/page_owner.o > > > + 1396 32 8 1436 59c mm/page_ext.o > > > > > > -Although, roughly, 8 KB code is added in total, page_alloc.o increase by > > > -520 bytes and less than half of it is in hotpath. Building the kernel with > > > +Although, roughly, 9 KB code is added in total, page_alloc.o increase by > > > +632 bytes and less than half of it is in hotpath. Building the kernel with > > > page owner and turning it on if needed would be great option to debug > > > kernel memory problem. > > > > This seems like a fine patch...but I do have to wonder if it really > > makes sense to maintain this information, which will surely be subject > > to frequent change. Perhaps the whole thing is better replaced with a > > line saying that enabling page owner adds ~9KB? > > > > The size figure above is from size(1) from binutils, for which the > command is run (maybe) against vmlinux. > > So I would like to say "Enabling page owner increases vmlinux size by > several kilobytes." Looks like original text tried to emphasize that there is no significant change to page allocator code, and I think it's worth keeping it. E.g. leaving something like "Although, enabling page owner increases kernel size by several kilobytes, most of this code is outside page allocator and its hot path." instead of size(1) output and the sentences before and after it. > Thanks. > > -- > An old man doll... just what I always wanted! - Clara -- Sincerely yours, Mike.