From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (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 A850D3090C4; Wed, 22 Apr 2026 01:52:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776822772; cv=none; b=Q9WZq81AN3VhgbigSa2r9t5wxa96Eg2UtXT7NWELWGBbLH5t2deBQrrerKqss7fHc7c8azctUA9qetLco132UeUXf2rii+W5uI4wzrlsCaqqOtd8OaYfGYkhw1LG4uqNpWyBZHkoyyn0Sfs8YDUe16+wqYYeZQcXwu7dcHLj5f8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776822772; c=relaxed/simple; bh=d3/dSb8VCsfS1PnI0yLe8lTP/fXOz2nNcgCYfTB7PVE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i2Ug/kg4rwMHhGnFE0xXQs1oNZmKNnj9ME40rjFvEzg9w26J/7GM2yPQai9EAi1wvGzjb3YM8Wj3HzXUNsSTSjLQU7HkeSyrHYqMcY4Xwgx8YxTkVNzNuyy/O5cLsAQqyND8b5NIblTZon6iwXILX+R6Cz17ussAm2t5GdKnv0A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=VqiApriF; arc=none smtp.client-ip=220.197.31.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="VqiApriF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=dE Z9FIUPUF+T6ETjcmLX+Rkx/mVcnjQZFx9WuuF6ilM=; b=VqiApriFvRN4Z6E9no 7/+64z/mVsdsVapf9Ggzdz2vRtv3fAx+fhgHvdYgouQBq398YHi0asb6eX3Ah8Ar Rovw21Cz7AiuPIyUc7rNq4hsD/B4sr2IoQvesU32H1oh21lrEuM8a1O534MLTGXI WGmCfvLfFgz8K6M47zBO/4mig= Received: from liubaolin-VMware-Virtual-Platform.localdomain (unknown []) by gzga-smtp-mtada-g1-0 (Coremail) with SMTP id _____wA3Hx+uKehpOCzjAw--.387S4; Wed, 22 Apr 2026 09:52:01 +0800 (CST) From: Baolin Liu To: tytso@mit.edu, adilger.kernel@dilger.ca, ojaswin@linux.ibm.com, ritesh.list@gmail.com, yi.zhang@huawei.com Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, wangguanyu@vivo.com, liubaolin12138@163.com, Baolin Liu , Andreas Dilger Subject: [PATCH v3 v3 2/2] ext4: allow clearing mballoc stats through mb_stats Date: Wed, 22 Apr 2026 09:50:25 +0800 Message-ID: <20260422015026.7170-3-liubaolin12138@163.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260422015026.7170-1-liubaolin12138@163.com> References: <20260422015026.7170-1-liubaolin12138@163.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wA3Hx+uKehpOCzjAw--.387S4 X-Coremail-Antispam: 1Uf129KBjvJXoW3JrW8GFyxCr45CF1fGrW3Jrb_yoW7tFyUpF s8ZFyxGr18Wa47uws7Gr4xZw1Yy3W8Cw1UKryIv34rur9Iqr9YyF1rtryjyFyYgrWUAayk XF429ryUGr42ka7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0z_73kDUUUUU= X-CM-SenderInfo: xolxutxrol0iasrtmqqrwthudrp/xtbCwgEP2WnoKcE7yQAA3O From: Baolin Liu Make /proc/fs/ext4//mb_stats writable and clear the runtime mballoc statistics when 0 is written. Update the related documentation accordingly. Reviewed-by: Ojaswin Mujoo Reviewed-by: Andreas Dilger Reviewed-by: Ritesh Harjani (IBM) Reviewed-by: Zhang Yi Signed-off-by: Baolin Liu --- Documentation/admin-guide/ext4.rst | 5 ++++ Documentation/filesystems/proc.rst | 3 +++ fs/ext4/ext4.h | 1 + fs/ext4/mballoc.c | 29 ++++++++++++++++++++++ fs/ext4/sysfs.c | 40 ++++++++++++++++++++++++++++-- 5 files changed, 76 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index ac0c709ea9e7..fb3887cd5e44 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -436,6 +436,11 @@ Files in /proc/fs/ext4/ mb_groups details of multiblock allocator buddy cache of free blocks + mb_stats + reports runtime statistics from the multiblock allocator + (mballoc). Writing 0 to this file clears the current + statistics. + /sys entries ============ diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index b0c0d1b45b99..7ce02573a3d9 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -1634,6 +1634,9 @@ directory are shown in Table 1-12, below. ============== ========================================================== File Content mb_groups details of multiblock allocator buddy cache of free blocks + mb_stats reports runtime statistics from the multiblock allocator + (mballoc). Writing 0 to this file clears the current + statistics. ============== ========================================================== 1.9 /proc/consoles diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 293f698b7042..3223e73612ae 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2994,6 +2994,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino, extern const struct seq_operations ext4_mb_seq_groups_ops; extern const struct seq_operations ext4_mb_seq_structs_summary_ops; extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset); +extern void ext4_mb_stats_clear(struct ext4_sb_info *sbi); extern int ext4_mb_init(struct super_block *); extern void ext4_mb_release(struct super_block *); extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *, diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 1e13ef62cb9d..79ddfa935813 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4723,6 +4723,35 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) trace_ext4_mballoc_prealloc(ac); } +void ext4_mb_stats_clear(struct ext4_sb_info *sbi) +{ + int i; + + atomic_set(&sbi->s_bal_reqs, 0); + atomic_set(&sbi->s_bal_success, 0); + atomic_set(&sbi->s_bal_allocated, 0); + atomic_set(&sbi->s_bal_groups_scanned, 0); + + for (i = 0; i < EXT4_MB_NUM_CRS; i++) { + atomic64_set(&sbi->s_bal_cX_hits[i], 0); + atomic64_set(&sbi->s_bal_cX_groups_considered[i], 0); + atomic_set(&sbi->s_bal_cX_ex_scanned[i], 0); + atomic64_set(&sbi->s_bal_cX_failed[i], 0); + } + + atomic_set(&sbi->s_bal_ex_scanned, 0); + atomic_set(&sbi->s_bal_goals, 0); + atomic_set(&sbi->s_bal_stream_goals, 0); + atomic_set(&sbi->s_bal_len_goals, 0); + atomic_set(&sbi->s_bal_2orders, 0); + atomic_set(&sbi->s_bal_breaks, 0); + atomic_set(&sbi->s_mb_lost_chunks, 0); + atomic_set(&sbi->s_mb_buddies_generated, 0); + atomic64_set(&sbi->s_mb_generation_time, 0); + atomic_set(&sbi->s_mb_preallocated, 0); + atomic_set(&sbi->s_mb_discarded, 0); +} + /* * Called on failure; free up any blocks from the inode PA for this * context. We don't need this for MB_GROUP_PA because we only change diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index b87d7bdab06a..e90885d470ab 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -52,6 +52,42 @@ typedef enum { static const char proc_dirname[] = "fs/ext4"; static struct proc_dir_entry *ext4_proc_root; +static int ext4_mb_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, ext4_seq_mb_stats_show, pde_data(inode)); +} + +static ssize_t ext4_mb_stats_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct super_block *sb = pde_data(file_inode(file)); + char kbuf[2]; + + if (count == 0 || count > sizeof(kbuf)) + return -EINVAL; + + if (copy_from_user(kbuf, buf, count)) + return -EFAULT; + + if (count == 2) { + if (kbuf[0] != '0' || kbuf[1] != '\n') + return -EINVAL; + } else if (kbuf[0] != '0') { + return -EINVAL; + } + + ext4_mb_stats_clear(EXT4_SB(sb)); + return count; +} + +static const struct proc_ops ext4_mb_stats_proc_ops = { + .proc_open = ext4_mb_stats_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = single_release, + .proc_write = ext4_mb_stats_write, +}; + struct ext4_attr { struct attribute attr; short attr_id; @@ -630,8 +666,8 @@ int ext4_register_sysfs(struct super_block *sb) ext4_fc_info_show, sb); proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc, &ext4_mb_seq_groups_ops, sb); - proc_create_single_data("mb_stats", 0444, sbi->s_proc, - ext4_seq_mb_stats_show, sb); + proc_create_data("mb_stats", 0644, sbi->s_proc, + &ext4_mb_stats_proc_ops, sb); proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc, &ext4_mb_seq_structs_summary_ops, sb); } -- 2.51.0