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 471231DC079 for ; Mon, 7 Oct 2024 16:52:15 +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=1728319936; cv=none; b=gBO0bGqBiIkgDqs5rNMCD0uoijkLfxL9etAkJJpAM9047z2lW8FDMsAZi6y/97I6DPy0whRfh9V9/zmhSrKTliBnTaQgb+NKjiYsyoUSRwxGr1ShR/6VRU6/OX/dVOpkFy0rlFgnHpQHhBEwABDXOF59W0tkuT6oYJeGV+CfHcI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728319936; c=relaxed/simple; bh=McFR8CfgpnxksNQs6KtKlTa460EvJpbtOvh/Sm4lYCE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rDQNiubaOdI1RQxeTTsMFti2I/GBBHWyvmQVzKfgVZnvxhcdGlFYFh2LpBTaiQWTnlK+E9wO6giXgjDFETUMlFJ9J/zymmDr7ku0qFS8co5B7VUQq9VcDa6pS6j5LjUz8JNca3DzQvDGzrrl6eSZuynnUzFlxNskHuCeFXvqktI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NifajxMl; 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="NifajxMl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96671C4CEC6; Mon, 7 Oct 2024 16:52:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728319935; bh=McFR8CfgpnxksNQs6KtKlTa460EvJpbtOvh/Sm4lYCE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NifajxMl/qi1VfPGNZIfvKjpMmnl/IP6NF0mW1lU1NZ6arMQBQa0/v5j8DrHXzqlN 1Sj1SQT5wxP1GchJLtpPjHJSjA0Ku4s5UQYfS+ATfbYSxXNKUB81ug2/VG1fo0b4ji eS/Ltc2/h42GFAInxqkLWG0Rjcuy6hdHE6Z0LjuiI7YoXZzLYFWIWEsvJcXVuXCFun ZN4TcZESCB4LV5HTfHKWFnoQaZZnpycy9bkn5WugOlN0FU0kcyu+OHmkvLJgwQH9yr Lkz/fOcK6NxmZ2e5bi0lcOZj8BdLSn9SzDOyocEdD+SoIAqOvorErYzdVcISuhhqNK Dyow4yn2yFu9A== Date: Mon, 7 Oct 2024 16:52:14 +0000 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] f2fs: use per-log target_bitmap to improve lookup performace of ssr allocation Message-ID: References: <20240411082354.1691820-1-chao@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240411082354.1691820-1-chao@kernel.org> Hi Chao, This introduces another bitmap increasing memory footprint. Do we know how much performance benefit with this? On 04/11, Chao Yu wrote: > After commit 899fee36fac0 ("f2fs: fix to avoid data corruption by > forbidding SSR overwrite"), valid block bitmap of current openned > segment is fixed, let's introduce a per-log bitmap instead of temp > bitmap to avoid unnecessary calculation overhead whenever allocating > free slot w/ SSR allocator. > > Signed-off-by: Chao Yu > --- > v2: > - rebase to last dev-test branch. > fs/f2fs/segment.c | 30 ++++++++++++++++++++++-------- > fs/f2fs/segment.h | 1 + > 2 files changed, 23 insertions(+), 8 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 6474b7338e81..af716925db19 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -2840,31 +2840,39 @@ static int new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec) > return 0; > } > > -static int __next_free_blkoff(struct f2fs_sb_info *sbi, > - int segno, block_t start) > +static void __get_segment_bitmap(struct f2fs_sb_info *sbi, > + unsigned long *target_map, > + int segno) > { > struct seg_entry *se = get_seg_entry(sbi, segno); > int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long); > - unsigned long *target_map = SIT_I(sbi)->tmp_map; > unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map; > unsigned long *cur_map = (unsigned long *)se->cur_valid_map; > int i; > > for (i = 0; i < entries; i++) > target_map[i] = ckpt_map[i] | cur_map[i]; > +} > + > +static int __next_free_blkoff(struct f2fs_sb_info *sbi, unsigned long *bitmap, > + int segno, block_t start) > +{ > + __get_segment_bitmap(sbi, bitmap, segno); > > - return __find_rev_next_zero_bit(target_map, BLKS_PER_SEG(sbi), start); > + return __find_rev_next_zero_bit(bitmap, BLKS_PER_SEG(sbi), start); > } > > static int f2fs_find_next_ssr_block(struct f2fs_sb_info *sbi, > - struct curseg_info *seg) > + struct curseg_info *seg) > { > - return __next_free_blkoff(sbi, seg->segno, seg->next_blkoff + 1); > + return __find_rev_next_zero_bit(seg->target_map, > + BLKS_PER_SEG(sbi), seg->next_blkoff + 1); > } > > bool f2fs_segment_has_free_slot(struct f2fs_sb_info *sbi, int segno) > { > - return __next_free_blkoff(sbi, segno, 0) < BLKS_PER_SEG(sbi); > + return __next_free_blkoff(sbi, SIT_I(sbi)->tmp_map, segno, 0) < > + BLKS_PER_SEG(sbi); > } > > /* > @@ -2890,7 +2898,8 @@ static int change_curseg(struct f2fs_sb_info *sbi, int type) > > reset_curseg(sbi, type, 1); > curseg->alloc_type = SSR; > - curseg->next_blkoff = __next_free_blkoff(sbi, curseg->segno, 0); > + curseg->next_blkoff = __next_free_blkoff(sbi, curseg->target_map, > + curseg->segno, 0); > > sum_page = f2fs_get_sum_page(sbi, new_segno); > if (IS_ERR(sum_page)) { > @@ -4635,6 +4644,10 @@ static int build_curseg(struct f2fs_sb_info *sbi) > sizeof(struct f2fs_journal), GFP_KERNEL); > if (!array[i].journal) > return -ENOMEM; > + array[i].target_map = f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, > + GFP_KERNEL); > + if (!array[i].target_map) > + return -ENOMEM; > if (i < NR_PERSISTENT_LOG) > array[i].seg_type = CURSEG_HOT_DATA + i; > else if (i == CURSEG_COLD_DATA_PINNED) > @@ -5453,6 +5466,7 @@ static void destroy_curseg(struct f2fs_sb_info *sbi) > for (i = 0; i < NR_CURSEG_TYPE; i++) { > kfree(array[i].sum_blk); > kfree(array[i].journal); > + kfree(array[i].target_map); > } > kfree(array); > } > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > index e1c0f418aa11..10f3e44f036f 100644 > --- a/fs/f2fs/segment.h > +++ b/fs/f2fs/segment.h > @@ -292,6 +292,7 @@ struct curseg_info { > struct f2fs_summary_block *sum_blk; /* cached summary block */ > struct rw_semaphore journal_rwsem; /* protect journal area */ > struct f2fs_journal *journal; /* cached journal info */ > + unsigned long *target_map; /* bitmap for SSR allocator */ > unsigned char alloc_type; /* current allocation type */ > unsigned short seg_type; /* segment type like CURSEG_XXX_TYPE */ > unsigned int segno; /* current segment number */ > -- > 2.40.1