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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 0BA9EC433DF for ; Tue, 11 Aug 2020 07:54:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E584C206B2 for ; Tue, 11 Aug 2020 07:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728252AbgHKHyr (ORCPT ); Tue, 11 Aug 2020 03:54:47 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:59264 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728133AbgHKHyp (ORCPT ); Tue, 11 Aug 2020 03:54:45 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 7D23CB3EBB3893400E5D; Tue, 11 Aug 2020 15:54:40 +0800 (CST) Received: from [10.164.122.247] (10.164.122.247) by smtp.huawei.com (10.3.19.212) with Microsoft SMTP Server (TLS) id 14.3.487.0; Tue, 11 Aug 2020 15:54:35 +0800 Subject: Re: [f2fs-dev] [PATCH] f2fs: change virtual mapping way for compression pages To: Daeho Jeong CC: Gao Xiang , Daeho Jeong , , , References: <20200811033753.783276-1-daeho43@gmail.com> <20200811071552.GA8365@xiangao.remote.csb> From: Chao Yu Message-ID: <3059d7b0-cf50-4315-e5a9-8d9c00965a7c@huawei.com> Date: Tue, 11 Aug 2020 15:54:35 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200811071552.GA8365@xiangao.remote.csb> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.164.122.247] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/8/11 15:15, Gao Xiang wrote: > On Tue, Aug 11, 2020 at 12:37:53PM +0900, Daeho Jeong wrote: >> From: Daeho Jeong >> >> By profiling f2fs compression works, I've found vmap() callings are >> bottlenecks of f2fs decompression path. Changing these with >> vm_map_ram(), we can enhance f2fs decompression speed pretty much. >> >> [Verification] >> dd if=/dev/zero of=dummy bs=1m count=1000 >> echo 3 > /proc/sys/vm/drop_caches >> dd if=dummy of=/dev/zero bs=512k >> >> - w/o compression - >> 1048576000 bytes (0.9 G) copied, 1.999384 s, 500 M/s >> 1048576000 bytes (0.9 G) copied, 2.035988 s, 491 M/s >> 1048576000 bytes (0.9 G) copied, 2.039457 s, 490 M/s >> >> - before patch - >> 1048576000 bytes (0.9 G) copied, 9.146217 s, 109 M/s >> 1048576000 bytes (0.9 G) copied, 9.997542 s, 100 M/s >> 1048576000 bytes (0.9 G) copied, 10.109727 s, 99 M/s >> >> - after patch - >> 1048576000 bytes (0.9 G) copied, 2.253441 s, 444 M/s >> 1048576000 bytes (0.9 G) copied, 2.739764 s, 365 M/s >> 1048576000 bytes (0.9 G) copied, 2.185649 s, 458 M/s > > Indeed, vmap() approach has some impact on the whole > workflow. But I don't think the gap is such significant, > maybe it relates to unlocked cpufreq (and big little > core difference if it's on some arm64 board). Agreed, I guess there should be other reason causing the large performance gap, scheduling, frequency, or something else. > > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > . >