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 8F482C001DB for ; Mon, 14 Aug 2023 12:29:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230310AbjHNM3D (ORCPT ); Mon, 14 Aug 2023 08:29:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230358AbjHNM2r (ORCPT ); Mon, 14 Aug 2023 08:28:47 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0159CCC for ; Mon, 14 Aug 2023 05:28:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1692016126; x=1723552126; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=cpc4XVuM51SJ2B/O4lQNuNKlc1XAvLGUzgMfcbN3Plk=; b=bGyjhBaPcqSf0s0jL/HRCgE+GpTaVwU8WSXDWV/JanpSBv3oVD3Bo+87 sw19wJDrR2inHqnZyycSmmcYq9+cE6TB+QnniVgf8S74JbzSO+VvVzdvF 2VfXcdFWxGty3PBy6Qi6X4rmfUojBgB3lTVyit/PlHpN7IcbY0XBBXCKa 5gotASGwX1E9yXtNG9Fd40Rm+i9t7o9ATlODkEfRjBlO6pjm1dTjp2au7 q46E5AJJgKMf4PAUkWOIYnkwya/GY4rV9iDBuppXNJNc8zdT2Ot8IBC8Q +6O/dE1UUm1vAYNV0qUJDBHO7xQPK6PVsPMlR7MMMXzdX1eGunH46wfiQ Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10802"; a="352353560" X-IronPort-AV: E=Sophos;i="6.01,172,1684825200"; d="scan'208";a="352353560" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2023 05:28:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10802"; a="823434944" X-IronPort-AV: E=Sophos;i="6.01,172,1684825200"; d="scan'208";a="823434944" Received: from smile.fi.intel.com ([10.237.72.54]) by FMSMGA003.fm.intel.com with ESMTP; 14 Aug 2023 05:28:43 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.96) (envelope-from ) id 1qVWgb-004XHM-19; Mon, 14 Aug 2023 15:28:41 +0300 Date: Mon, 14 Aug 2023 15:28:41 +0300 From: 'Andy Shevchenko' To: David Laight Cc: 'Petr Mladek' , Marco Elver , "linux-kernel@vger.kernel.org" , "kasan-dev@googlegroups.com" , "linux-mm@kvack.org" , Steven Rostedt , Rasmus Villemoes , Sergey Senozhatsky , Alexander Potapenko , Dmitry Vyukov , Andrew Morton Subject: Re: [PATCH v2 2/3] lib/vsprintf: Split out sprintf() and friends Message-ID: References: <20230805175027.50029-1-andriy.shevchenko@linux.intel.com> <20230805175027.50029-3-andriy.shevchenko@linux.intel.com> <900a99a7c90241698c8a2622ca20fa96@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 14, 2023 at 08:12:55AM +0000, David Laight wrote: > From: Andy Shevchenko > > Sent: 10 August 2023 14:14 > > On Wed, Aug 09, 2023 at 08:48:54AM +0000, David Laight wrote: ... > > > > If you split headers into so many small pieces then all > > > > source files will start with 3 screens of includes. I do not see > > > > how this helps with maintainability. > > > > > > You also slow down compilations. > > > > Ingo's patches showed the opposite. Do you have actual try and numbers? > > The compiler has to open the extra file on every compile. > If you include it from lots of different places it has to open > it for each one (to find the include guard). > Any attempted compiler optimisations have the same much the > same problem as #pragma once. > > With a long -I list even finding the file can take a while. > > Probably most obvious when using NFS mounted filesystems. > Especially the 'traditional' NFS protocol that required a > message 'round trip' for each element of the directory path. Right, as I said come up with numbers. Ingo did that, so can you. His numbers shows _increase_ of build speed. -- With Best Regards, Andy Shevchenko