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 CCADDC00528 for ; Fri, 28 Jul 2023 11:13:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236183AbjG1LNL (ORCPT ); Fri, 28 Jul 2023 07:13:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234120AbjG1LNK (ORCPT ); Fri, 28 Jul 2023 07:13:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FD282723; Fri, 28 Jul 2023 04:13:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1B35E620FD; Fri, 28 Jul 2023 11:13:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E85DCC433C8; Fri, 28 Jul 2023 11:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690542788; bh=SXf0CvhgUkGm+fNUV5KHDN/D2FZxDlPPjw5urZT6Keo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mGv7o46bKMQNQnFbWlWW3EHhpoXV4D8cil6h9KcxnevCmI3Ao5DqUZ3WkB1xbx+s6 nrXbrhJPUlIv0ajoKUAB1wwvHp5kdNLesTg8KDWLeZhwV14QJgRqyx0vVFnQcabl+p oIvW56PEpsXwGaCujj1wPVF8JlShTANqmOVIWzCQ= Date: Fri, 28 Jul 2023 13:13:05 +0200 From: Greg KH To: Muhammad Usama Anjum Cc: =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= , Paul Gofman , Peter Xu , David Hildenbrand , Andrew Morton , Andrei Vagin , Danylo Mocherniuk , Cyrill Gorcunov , Mike Rapoport , Nadav Amit , Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Matthew Wilcox , Pasha Tatashin , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, kernel@collabora.com, =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= Subject: Re: WIP: Performance improvements Message-ID: <2023072809-mowing-amaze-efb5@gregkh> References: <20230727093637.1262110-1-usama.anjum@collabora.com> <20230727093637.1262110-3-usama.anjum@collabora.com> <6b6a4e1c-a9e9-9592-d5b4-3c9210c8b650@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6b6a4e1c-a9e9-9592-d5b4-3c9210c8b650@collabora.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Jul 28, 2023 at 04:02:02PM +0500, Muhammad Usama Anjum wrote: > We are optimizing for more performance. Please find the change-set below > for easy review before next revision and post your comments: > > - Replace memcpy() with direct copy as it proving to be very expensive > - Don't check if PAGE_IS_FILE if no mask needs it as it is very > expensive to check per pte > - Add question in comment for discussion purpose > - Add fast path for exclusive WP for ptes Please read the kernel documentation for how to properly submit patches (i.e. don't mush them all together into one and then properly describe what you are doing and why you are doing it). Also actually test the patch and prove (or disprove) if it does matter for performance. good luck! greg k-h