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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 177AAC10DCE for ; Wed, 11 Mar 2020 03:07:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD45621927 for ; Wed, 11 Mar 2020 03:07:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583896064; bh=WJTonuZBHjT2gmhJN5zqDlZVwWoWWxEFvlg0bLkgcg0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=BEqu7ylfoJVCHrOJ5dBhqUhqwvhQLuUdcDUWcgT2ER25I2j94W4+ARThey2hp3sNg S9t7UuW2Gar2p1UlGPaUc1H5tG9tq7TGZnxDuY9n0nB+otb1jSM4p1HfRtItBNuDau WBmVjjRtfSmlLEW4MrAmPVHEl7sHz2hyxy8n6Ik0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727953AbgCKDHn (ORCPT ); Tue, 10 Mar 2020 23:07:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:49992 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727307AbgCKDHn (ORCPT ); Tue, 10 Mar 2020 23:07:43 -0400 Received: from localhost (unknown [104.132.1.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 551A32146E; Wed, 11 Mar 2020 03:07:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583896062; bh=WJTonuZBHjT2gmhJN5zqDlZVwWoWWxEFvlg0bLkgcg0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BlJ4JbogrNYdixG1Oj5q7F5cAsJpnZceO2kKG3ORkTbq8cZKavuMhj2NhkmuqYyQq V9JFpe/ztou8PEXtRCplLa35qZdEIddXbPhDmhQAo2J5krlVS1tXv7Xoz/xlMAjDcV VQ45Hozkk46oYOKTfr2rmEA39J30tHA5TRCG9v9E= Date: Tue, 10 Mar 2020 20:07:41 -0700 From: Jaegeuk Kim To: Chao Yu Cc: Eric Biggers , linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 1/5] f2fs: change default compression algorithm Message-ID: <20200311030741.GA119277@google.com> References: <20200310125009.12966-1-yuchao0@huawei.com> <20200310161515.GA1067@sol.localdomain> <4d8384b9-88fe-2a15-13ff-238d9fd4027a@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4d8384b9-88fe-2a15-13ff-238d9fd4027a@huawei.com> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/11, Chao Yu wrote: > On 2020/3/11 0:15, Eric Biggers wrote: > > On Tue, Mar 10, 2020 at 08:50:05PM +0800, Chao Yu wrote: > >> Use LZ4 as default compression algorithm, as compared to LZO, it shows > >> almost the same compression ratio and much better decompression speed. > >> > >> Signed-off-by: Chao Yu > >> --- > >> fs/f2fs/super.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > >> index db3a63f7c769..ebffe7aa08ee 100644 > >> --- a/fs/f2fs/super.c > >> +++ b/fs/f2fs/super.c > >> @@ -1577,7 +1577,7 @@ static void default_options(struct f2fs_sb_info *sbi) > >> F2FS_OPTION(sbi).test_dummy_encryption = false; > >> F2FS_OPTION(sbi).s_resuid = make_kuid(&init_user_ns, F2FS_DEF_RESUID); > >> F2FS_OPTION(sbi).s_resgid = make_kgid(&init_user_ns, F2FS_DEF_RESGID); > >> - F2FS_OPTION(sbi).compress_algorithm = COMPRESS_LZO; > >> + F2FS_OPTION(sbi).compress_algorithm = COMPRESS_LZ4; > >> F2FS_OPTION(sbi).compress_log_size = MIN_COMPRESS_LOG_SIZE; > >> F2FS_OPTION(sbi).compress_ext_cnt = 0; > >> F2FS_OPTION(sbi).bggc_mode = BGGC_MODE_ON; > > > > This makes sense, but it's unclear to me why comparing the different compression > > algorithms is happening just now, after support for both LZO and LZ4 was already > > merged into mainline and now has to be supported forever. During review months > > ago, multiple people suggested that LZ4 is better than LZO, so there's not much > > reason to support LZO at all. > > Agreed, > > Jaegeuk, thoughts? Supporting LZO or whatever algorithms looks fine to me as long as kernel supports without huge maintenance effort. I think it'd be good to provide a way for users to compare several algorithms in whatever their ways. And, unfortunately, I don't think we can remove LZO at this point, even for -rc. Thanks, > > Let me remove lzo if you have no objection on this. > > Thanks, > > > > > - Eric > > . > >