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 DC633243378 for ; Thu, 7 Aug 2025 08:38:28 +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=1754555908; cv=none; b=HPQqbJRC+xjVb+mOlOJpT7Moj/mWQ2QR2O7QvtY9BOjvnFg8RhW4+ZdU7Md7Vf5YazlmDZI02if3pvDn6WcUyA6vu19cbPyPcbkLXYpZuW4zYb2FRHykNfzSqVGEI53oWoEZdkG9/S+yqDBTIxcbQfnoyk3Xw4e6Lr7mT/OhEFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754555908; c=relaxed/simple; bh=Z8juUoPKnzPVrOKAT2bg4L+pwxA3Dh5VzHaqon9AtdY=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=BSGXcSAndJpHRPg3hPLsGG9KM9qU+nqrb72vqDSW8Ez/UQuwCNDXEXDHGWjNFgP2/nyJIKlLzQUuLjvsb6PDzMqurEWDTMOT5CtXZE1gKH7rv+Su4+YsELL4z2H3ZfPtcMHcKXxBRgWYVMENtddnnAvssPKVbd3lCdfSsHWH83o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a4i1S7z0; 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="a4i1S7z0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FF30C4CEEB; Thu, 7 Aug 2025 08:38:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754555908; bh=Z8juUoPKnzPVrOKAT2bg4L+pwxA3Dh5VzHaqon9AtdY=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=a4i1S7z08sK8aku7qzbi7wmNbi4FqPzUt5FTlSf2dqaMKdRhjru56Dhd7iSbmWZNe R4dasbTCY5TIpttRvcLMEzdkJ4w/2u8MFPl0mYrLlqQg+GbfpwTZCfm4g9ngw3GSDB p7U6WeFgj0kFPiqD+T+KxzXfGC3CQvLsgMyKeHP4TBK4inkJMpUzRj2/F9uqPe77pH GYLEo0MwBnepe3ByTekS6X4zdRM1k17TZGf9oF2w6TdK0u+v+7mI7QfVdCR1YtjvYu NvKm2n/B94fuwZTG7NyCTTaGOt2omobcRtz4ThsVbwrlfqFR1hPma0aRTWSZBB90U6 sc3teWMF04WPA== Message-ID: Date: Thu, 7 Aug 2025 16:38:25 +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] f2fs: Add bggc_block_io to adjust the priority of BG_GC when issuing IO To: Liao Yuanhong , Jaegeuk Kim References: <20250805132208.486601-1-liaoyuanhong@vivo.com> <20250806070905.71012-1-liaoyuanhong@vivo.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20250806070905.71012-1-liaoyuanhong@vivo.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/6/25 15:09, Liao Yuanhong wrote: > Currently, we have encountered some issues while testing ZUFS. In > situations near the storage limit (e.g., 50GB remaining), and after > simulating fragmentation by repeatedly writing and deleting data, we found > that application installation and startup tests conducted after idling for > a few minutes take significantly longer several times that of traditional > UFS. Tracing the operations revealed that the majority of I/Os were issued > by background GC, which blocks normal I/O operations. > > Under normal circumstances, ZUFS indeed requires more background GC and > employs a more aggressive GC strategy. However, I aim to find a way to > minimize the impact on regular I/O operations under these near-limit > conditions. To address this, I have introduced a bggc_block_io feature, > which controls the prioritization of background GC in the presence of I/Os. > This switch can be adjusted at the framework level to implement different > strategies. If set to ALL_IO_PRIOR, all background GC operations will be > skipped during active I/O issuance. The default option remains consistent > with the current strategy, ensuring no change in behavior. > > Signed-off-by: Liao Yuanhong > --- > Changes in v2: > Non ZUFS can also be adjusted through this option. > --- > Documentation/ABI/testing/sysfs-fs-f2fs | 13 +++++++++++++ > fs/f2fs/f2fs.h | 18 +++++++++++------- > fs/f2fs/super.c | 2 ++ > fs/f2fs/sysfs.c | 9 +++++++++ > 4 files changed, 35 insertions(+), 7 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs > index bc0e7fefc39d..12fda11d4da5 100644 > --- a/Documentation/ABI/testing/sysfs-fs-f2fs > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs > @@ -883,3 +883,16 @@ Date: June 2025 > Contact: "Daeho Jeong" > Description: Control GC algorithm for boost GC. 0: cost benefit, 1: greedy > Default: 1 > + > +What: /sys/fs/f2fs//bggc_block_io > +Date: August 2025 > +Contact: "Liao Yuanhong" > +Description: Used to adjust the BG_GC priority when issuing IO, with a default value > + of 1. Default value is 2 if CONFIG_BLK_DEV_ZONED is off? Thanks, > + > + ================== ============================================= > + value description > + bggc_block_io = 0 Prioritize background GC > + bggc_block_io = 1 Stop background GC only when issuing read I/O > + bggc_block_io = 2 Stop background GC when issuing I/O > + ================== ============================================= > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 46be7560548c..fe41b733fbc2 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -155,6 +155,12 @@ enum blkzone_allocation_policy { > BLKZONE_ALLOC_PRIOR_CONV, /* Prioritize writing to conventional zones */ > }; > > +enum bggc_block_io_policy { > + BGGC_PRIOR, > + READ_IO_PRIOR, > + ALL_IO_PRIOR, > +}; > + > /* > * An implementation of an rwsem that is explicitly unfair to readers. This > * prevents priority inversion when a low-priority reader acquires the read lock > @@ -1804,6 +1810,7 @@ struct f2fs_sb_info { > spinlock_t dev_lock; /* protect dirty_device */ > bool aligned_blksize; /* all devices has the same logical blksize */ > unsigned int first_seq_zone_segno; /* first segno in sequential zone */ > + unsigned int bggc_block_io; /* For adjust the BG_GC priority when issuing IO */ > > /* For write statistics */ > u64 sectors_written_start; > @@ -2998,13 +3005,10 @@ static inline bool is_idle(struct f2fs_sb_info *sbi, int type) > if (sbi->gc_mode == GC_URGENT_HIGH) > return true; > > - if (zoned_gc) { > - if (is_inflight_read_io(sbi)) > - return false; > - } else { > - if (is_inflight_io(sbi, type)) > - return false; > - } > + if (sbi->bggc_block_io == READ_IO_PRIOR && is_inflight_read_io(sbi)) > + return false; > + if (sbi->bggc_block_io == ALL_IO_PRIOR && is_inflight_io(sbi, type)) > + return false; > > if (sbi->gc_mode == GC_URGENT_MID) > return true; > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index e16c4e2830c2..a21cecc5424e 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -4629,9 +4629,11 @@ static int f2fs_scan_devices(struct f2fs_sb_info *sbi) > > logical_blksize = bdev_logical_block_size(sbi->sb->s_bdev); > sbi->aligned_blksize = true; > + sbi->bggc_block_io = ALL_IO_PRIOR; > #ifdef CONFIG_BLK_DEV_ZONED > sbi->max_open_zones = UINT_MAX; > sbi->blkzone_alloc_policy = BLKZONE_ALLOC_PRIOR_SEQ; > + sbi->bggc_block_io = READ_IO_PRIOR; > #endif > > for (i = 0; i < max_devices; i++) { > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c > index f736052dea50..efea15209788 100644 > --- a/fs/f2fs/sysfs.c > +++ b/fs/f2fs/sysfs.c > @@ -674,6 +674,13 @@ static ssize_t __sbi_store(struct f2fs_attr *a, > sbi->blkzone_alloc_policy = t; > return count; > } > + > + if (!strcmp(a->attr.name, "bggc_block_io")) { > + if (t < BGGC_PRIOR || t > ALL_IO_PRIOR) > + return -EINVAL; > + sbi->bggc_block_io = t; > + return count; > + } > #endif > > #ifdef CONFIG_F2FS_FS_COMPRESSION > @@ -1172,6 +1179,7 @@ F2FS_SBI_GENERAL_RW_ATTR(max_read_extent_count); > #ifdef CONFIG_BLK_DEV_ZONED > F2FS_SBI_GENERAL_RO_ATTR(unusable_blocks_per_sec); > F2FS_SBI_GENERAL_RW_ATTR(blkzone_alloc_policy); > +F2FS_SBI_GENERAL_RW_ATTR(bggc_block_io); > #endif > F2FS_SBI_GENERAL_RW_ATTR(carve_out); > F2FS_SBI_GENERAL_RW_ATTR(reserved_pin_section); > @@ -1342,6 +1350,7 @@ static struct attribute *f2fs_attrs[] = { > #ifdef CONFIG_BLK_DEV_ZONED > ATTR_LIST(unusable_blocks_per_sec), > ATTR_LIST(blkzone_alloc_policy), > + ATTR_LIST(bggc_block_io), > #endif > #ifdef CONFIG_F2FS_FS_COMPRESSION > ATTR_LIST(compr_written_block),