From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D228E4405 for ; Wed, 18 Sep 2024 06:43:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726641828; cv=none; b=fwnfgCnk1nrsl5HzirK/8n9lHit9kGkWH+hQCLnfyvYkSC3gnfU+eQK/84HA315GG+oPVdMn3CBDM0VsaqPltjPL9LbtiwueG61751SGoqOqVjcJtTCZD0QprZxrudjn5Fky1SMcRX8SQ6AqpLPlF4p7809bJ30KcRnhzeicrDk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726641828; c=relaxed/simple; bh=YDkmVjADAn5ZsljbPwya7Vl8v9ZGj+0kyF+MMrdCVa4=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=Sphk6HGhuKmA3MEVvBxMZITIPz9rRoaehLtvjPt3cVf+Etj793cTmtH2urNPfU3L72z9QVjsxlXP1dQCYFE0e1TFVcxUGD6cbtl/SRybUmJGR07uhKqdh9wzSNDb0vy9/+9qrCkEy3/2ZHkqbY1wz6jXpECBt6aCmhQNttYus2s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=I8SD3xjJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I8SD3xjJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EC09C4CEC3; Wed, 18 Sep 2024 06:43:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726641828; bh=YDkmVjADAn5ZsljbPwya7Vl8v9ZGj+0kyF+MMrdCVa4=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=I8SD3xjJuEUMhOGbAohhBMrXpH2TQh5G+pHIWYeCK7q8IX7NKrzahsPDfjKDmwFK5 YmpUlaDOy20yX7GUh3b/yjxMdtH6xTHIYZUeMlCBhR2RXmV7VU8XhLrU8N1GMr/phY bOsiiKOw2JDEqAAjuBj5nvZnb/fdRuXSUZ9zJbvEBDxfqun3NAE9k80m0B2sfDiIh3 cOK8QaUQAb2urNJZ03J1ksTSp4ef3qmFezd1B+eGumutUOSGe1Us/KHUJX31GPlqXY DvSS+RVYIrMuhS/Oj5YmDxVjmRPkpVwu3xXt8DjLvckIigj6ozELVV/FMOpH7WdUiV Pk0jtTL5IwDTA== Message-ID: <17ceed17-b17f-42d9-8c82-79f1f4814c1a@kernel.org> Date: Wed, 18 Sep 2024 14:43:44 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/2] f2fs: introduce get_section_mtime To: liuderong@oppo.com, jaegeuk@kernel.org References: <1726123214-208356-1-git-send-email-liuderong@oppo.com> <1726123214-208356-3-git-send-email-liuderong@oppo.com> Content-Language: en-US From: Chao Yu In-Reply-To: <1726123214-208356-3-git-send-email-liuderong@oppo.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2024/9/12 14:40, liuderong@oppo.com wrote: > From: liuderong > > When segs_per_sec is larger than 1, section may contain free segments, > mtime should be the mean value of each valid segments, > so introduce get_section_mtime to exclude free segments in a section. > > Signed-off-by: liuderong > --- > fs/f2fs/f2fs.h | 2 ++ > fs/f2fs/gc.c | 15 ++------------- > fs/f2fs/segment.c | 41 ++++++++++++++++++++++++++++++++++++----- > 3 files changed, 40 insertions(+), 18 deletions(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 4dcdcdd..d6adf0f 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -3762,6 +3762,8 @@ enum rw_hint f2fs_io_type_to_rw_hint(struct f2fs_sb_info *sbi, > unsigned int f2fs_usable_segs_in_sec(struct f2fs_sb_info *sbi); > unsigned int f2fs_usable_blks_in_seg(struct f2fs_sb_info *sbi, > unsigned int segno); > +unsigned long long get_section_mtime(struct f2fs_sb_info *sbi, > + unsigned int segno); Hi Derong, It needs to add "f2fs_" prefix for get_section_mtime() to avoid global namespace pollution. > > #define DEF_FRAGMENT_SIZE 4 > #define MIN_FRAGMENT_SIZE 1 > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index 6299639..03c6117 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -332,20 +332,14 @@ static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) > static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) > { > struct sit_info *sit_i = SIT_I(sbi); > - unsigned int secno = GET_SEC_FROM_SEG(sbi, segno); > - unsigned int start = GET_SEG_FROM_SEC(sbi, secno); > unsigned long long mtime = 0; > unsigned int vblocks; > unsigned char age = 0; > unsigned char u; > - unsigned int i; > unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi); > > - for (i = 0; i < usable_segs_per_sec; i++) > - mtime += get_seg_entry(sbi, start + i)->mtime; > + mtime = get_section_mtime(sbi, segno); > vblocks = get_valid_blocks(sbi, segno, true); > - > - mtime = div_u64(mtime, usable_segs_per_sec); > vblocks = div_u64(vblocks, usable_segs_per_sec); > > u = BLKS_TO_SEGS(sbi, vblocks * 100); > @@ -485,10 +479,7 @@ static void add_victim_entry(struct f2fs_sb_info *sbi, > struct victim_sel_policy *p, unsigned int segno) > { > struct sit_info *sit_i = SIT_I(sbi); > - unsigned int secno = GET_SEC_FROM_SEG(sbi, segno); > - unsigned int start = GET_SEG_FROM_SEC(sbi, secno); > unsigned long long mtime = 0; > - unsigned int i; > > if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) { > if (p->gc_mode == GC_AT && > @@ -496,9 +487,7 @@ static void add_victim_entry(struct f2fs_sb_info *sbi, > return; > } > > - for (i = 0; i < SEGS_PER_SEC(sbi); i++) > - mtime += get_seg_entry(sbi, start + i)->mtime; > - mtime = div_u64(mtime, SEGS_PER_SEC(sbi)); > + mtime = get_section_mtime(sbi, segno); > > /* Handle if the system time has changed by the user */ > if (mtime < sit_i->min_mtime) > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 6627394..e62e722 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -5389,6 +5389,41 @@ unsigned int f2fs_usable_segs_in_sec(struct f2fs_sb_info *sbi) > return SEGS_PER_SEC(sbi); > } > > +unsigned long long get_section_mtime(struct f2fs_sb_info *sbi, > + unsigned int segno) > +{ > + unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi); > + unsigned int secno = 0, start = 0; > + struct free_segmap_info *free_i = FREE_I(sbi); > + unsigned int valid_seg_count = 0; > + unsigned long long mtime = 0; > + unsigned int i = 0; > + > + if (segno == NULL_SEGNO) > + return 0; No needed. > + > + secno = GET_SEC_FROM_SEG(sbi, segno); > + start = GET_SEG_FROM_SEC(sbi, secno); > + > + if (!__is_large_section(sbi)) > + return get_seg_entry(sbi, start + i)->mtime; > + > + for (i = 0; i < usable_segs_per_sec; i++) { > + /* for large section, only check the mtime of valid segments */ > + spin_lock(&free_i->segmap_lock); > + if (test_bit(start + i, free_i->free_segmap)) { > + mtime += get_seg_entry(sbi, start + i)->mtime; > + valid_seg_count++; > + } > + spin_unlock(&free_i->segmap_lock); > + } After commit 6f3a01ae9b72 ("f2fs: record average update time of segment"), mtime of segment starts to indicate average update time of segment. So it needs to change like this? for (i = 0; i < usable_segs_per_sec; i++) { struct seg_entry *se = get_seg_entry(sbi, start + i); mtime += se->mtime * se->valid_blocks; total_valid_blocks += se->valid_blocks; } if (total_valid_blocks == 0) return 0; return div_u64(mtime, total_valid_blocks); Thanks, > + > + if (valid_seg_count == 0) > + return 0; > + > + return div_u64(mtime, valid_seg_count); > +} > + > /* > * Update min, max modified time for cost-benefit GC algorithm > */ > @@ -5402,13 +5437,9 @@ static void init_min_max_mtime(struct f2fs_sb_info *sbi) > sit_i->min_mtime = ULLONG_MAX; > > for (segno = 0; segno < MAIN_SEGS(sbi); segno += SEGS_PER_SEC(sbi)) { > - unsigned int i; > unsigned long long mtime = 0; > > - for (i = 0; i < SEGS_PER_SEC(sbi); i++) > - mtime += get_seg_entry(sbi, segno + i)->mtime; > - > - mtime = div_u64(mtime, SEGS_PER_SEC(sbi)); > + mtime = get_section_mtime(sbi, segno); > > if (sit_i->min_mtime > mtime) > sit_i->min_mtime = mtime;