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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 C9C2BC433E0 for ; Fri, 3 Jul 2020 02:15:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD622207E8 for ; Fri, 3 Jul 2020 02:15:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726082AbgGCCNX (ORCPT ); Thu, 2 Jul 2020 22:13:23 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:60292 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726030AbgGCCNX (ORCPT ); Thu, 2 Jul 2020 22:13:23 -0400 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id ABB822F59E07BC97FD66; Fri, 3 Jul 2020 10:13:20 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.201) with Microsoft SMTP Server (TLS) id 14.3.487.0; Fri, 3 Jul 2020 10:13:17 +0800 Subject: Re: [PATCH RFC 2/5] f2fs: record average update time of segment To: Jaegeuk Kim CC: , , References: <20200630100428.19105-1-yuchao0@huawei.com> <20200630100428.19105-2-yuchao0@huawei.com> <20200701161927.GD1724572@google.com> From: Chao Yu Message-ID: <70776961-0430-0a9f-cf26-09a2cc192b07@huawei.com> Date: Fri, 3 Jul 2020 10:13:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200701161927.GD1724572@google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/7/2 0:19, Jaegeuk Kim wrote: > 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 {}. Updated, BTW, have fixed below compile error: m68k-linux-ld: fs/f2fs/segment.o: in function `update_segment_mtime': fs/f2fs/segment.c:2162: undefined reference to `__udivdi3' Thanks, > >> + 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 > . >