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=-7.1 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,URIBL_BLOCKED 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 024C2C433E0 for ; Wed, 1 Jul 2020 16:19:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C162D2080D for ; Wed, 1 Jul 2020 16:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593620370; bh=2zNupGrsJWVvIy1EGdDug2tvMr8j7918+kyHDf++ejA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=JaEGeuCluQGCgWABfneBXINzfkcmBrFMONu62gn9EMcQ0GAxEra6pkkhutwkxEmdx AgQxh6HojZwuJGwAocGHznf+RsjlR1wJt5Z9kFSy4k4NVhxI3W4FlS0jDceWk7SQrc tfdHKOT0KbzQyRmULJPF+KSByaNocUbf5UdUiqiI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732243AbgGAQT3 (ORCPT ); Wed, 1 Jul 2020 12:19:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:46014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729019AbgGAQT2 (ORCPT ); Wed, 1 Jul 2020 12:19:28 -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 DDAC7207BB; Wed, 1 Jul 2020 16:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593620368; bh=2zNupGrsJWVvIy1EGdDug2tvMr8j7918+kyHDf++ejA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KHDPOc0FLDP3WLnhF3VbexIDJ4vOZBhmmYCWfOGkeAvEzeZAlnQFI9ozskQG1IBio c0UByb07z0wVjS5DmK3dTO14yPvWnf5hFOz7qdeQMQcOBfWfPFvNEXweF6F3J5pImm /jMBf9Kpd7HLKQKcvg4J3TLlnnZg7dOBAbWdCRVo= Date: Wed, 1 Jul 2020 09:19:27 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org Subject: Re: [PATCH RFC 2/5] f2fs: record average update time of segment Message-ID: <20200701161927.GD1724572@google.com> References: <20200630100428.19105-1-yuchao0@huawei.com> <20200630100428.19105-2-yuchao0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200630100428.19105-2-yuchao0@huawei.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/30, Chao Yu wrote: > Previously, once we update one block in segment, we will update mtime of > segment to last time, making aged segment becoming freshest, result in > that GC with cost benefit algorithm missing such segment, So this patch > changes to record mtime as average block updating time instead of last > updating time. > > It's not needed to reset mtime for prefree segment, as se->valid_blocks > is zero, then old se->mtime won't take any weight with below calculation: > > se->mtime = (se->mtime * se->valid_blocks + mtime) / > (se->valid_blocks + 1); > > Signed-off-by: Chao Yu > --- > fs/f2fs/segment.c | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 863ec6f1fb87..906c313835ad 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -2150,6 +2150,22 @@ static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type, > __mark_sit_entry_dirty(sbi, segno); > } > > +static void update_segment_mtime(struct f2fs_sb_info *sbi, block_t blkaddr) > +{ > + unsigned int segno = GET_SEGNO(sbi, blkaddr); > + struct seg_entry *se = get_seg_entry(sbi, segno); > + unsigned long long mtime = get_mtime(sbi, false); > + > + if (!se->mtime) { Don't need {}. > + se->mtime = mtime; > + } else { > + se->mtime = (se->mtime * se->valid_blocks + mtime) / > + (se->valid_blocks + 1); > + } > + if (mtime > SIT_I(sbi)->max_mtime) > + SIT_I(sbi)->max_mtime = mtime; > +} > + > static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) > { > struct seg_entry *se; > @@ -2169,10 +2185,9 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) > f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) || > (new_vblocks > sbi->blocks_per_seg))); > > + update_segment_mtime(sbi, blkaddr); > + > se->valid_blocks = new_vblocks; > - se->mtime = get_mtime(sbi, false); > - if (se->mtime > SIT_I(sbi)->max_mtime) > - SIT_I(sbi)->max_mtime = se->mtime; > > /* Update valid block bitmap */ > if (del > 0) { > -- > 2.26.2