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 5D139C433F5 for ; Tue, 8 Feb 2022 01:49:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245730AbiBHBt3 (ORCPT ); Mon, 7 Feb 2022 20:49:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344209AbiBHBfj (ORCPT ); Mon, 7 Feb 2022 20:35:39 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C42E4C061355 for ; Mon, 7 Feb 2022 17:35:38 -0800 (PST) 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 95800B8170D for ; Tue, 8 Feb 2022 01:35:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B730C004E1; Tue, 8 Feb 2022 01:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1644284136; bh=o+NEaHYg1oMwFFbJTVtbm24NxkjLxuhPYXj4L9pEGzo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ZJpocSefDus7E3fo3k8k2+rstHENI67GChkDgaAffdBlqoIpcz1c3oGu5gDUsKnVC xUQHcsoEXzv1Heh4q//VHqx9XQLrGcRKMcC7uB6+xveGlZdlrwaKR61GYLHPhBCklK IHmLL5S6mw25t4f/cgqQXt2xi4/DVcjUXBuKta/Z/kZz1cPgW09y5zKxRqrpsA6gxL hWiyMlm21Ht63uRb1VA3OyhLsg5lvQ8Cyr28tkezF4mCxXojH56VSUHsMaMHJB2SPw Yl2ak0Kv7pMq2FLrzjyu4GoiLTlH0yqGX2qwrTRRsSfWNegTjaKAjiZAEGQ+WwrTzm QLaijvOHNFDLQ== Message-ID: <59da7f3e-92bd-1165-00e3-3dc18ae19aea@kernel.org> Date: Tue, 8 Feb 2022 09:35:29 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: [PATCH] f2fs: avoid unneeded preflush during checkpoint() Content-Language: en-US To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <20220207113516.9489-1-chao@kernel.org> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/2/8 3:14, Jaegeuk Kim wrote: > On 02/07, Chao Yu wrote: >> During checkpoint, we have committed preflush command via f2fs_flush_device_cache() > > 787 int f2fs_flush_device_cache(struct f2fs_sb_info *sbi) > 788 { > 789 int ret = 0, i; > 790 > 791 if (!f2fs_is_multi_device(sbi)) > 792 return 0; > > Seems a wrong assumption. Oh, I missed that f2fs_flush_device_cache was introduced to flush devices except first device when multi-device feature is on. for (i = 1; i < sbi->s_ndevs; i++) { int count = DEFAULT_RETRY_IO_COUNT; So, this patch seems wrong... Instead, below case looks wrong since it needs to trigger flush during checkpoint() no matter nobarrier is on or off. if (test_opt(sbi, NOBARRIER)) return 0; Thanks, > >> to persist all metadata pages except last #2 CP pack page, so we don't need to >> commit another preflush command in commit_checkpoint(), remove it to avoid unneeded >> write cache overhead. >> >> Signed-off-by: Chao Yu >> --- >> fs/f2fs/data.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >> index 8c417864c66a..15ac18bbbc8e 100644 >> --- a/fs/f2fs/data.c >> +++ b/fs/f2fs/data.c >> @@ -598,7 +598,7 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi, >> io->fio.op = REQ_OP_WRITE; >> io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC; >> if (!test_opt(sbi, NOBARRIER)) >> - io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA; >> + io->fio.op_flags |= REQ_FUA; >> } >> __submit_merged_bio(io); >> up_write(&io->io_rwsem); >> -- >> 2.32.0