From: Zizhi Wo Date: Mon, 24 Feb 2025 01:20:05 +0000 (+0800) Subject: ext4: update the comment about mb_optimize_scan X-Git-Tag: io_uring-6.15-20250403~67^2~12 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=243efbdf8ea665cd698cb02d03fbab6dbc55bf8e;p=linux-block.git ext4: update the comment about mb_optimize_scan Commit 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning") introduces the sysfs control interface "mb_max_linear_groups" to address the problem that rotational devices performance degrades when the "mb_optimize_scan" feature is enabled, which may result in distant block group allocation. However, the name of the interface was incorrect in the comment to the ext4/mballoc.c file, and this patch fixes it, without further changes. Signed-off-by: Zizhi Wo Reviewed-by: Baokun Li Reviewed-by: Ojaswin Mujoo Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250224012005.689549-1-wozizhi@huawei.com Signed-off-by: Theodore Ts'o --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index a67c52063a42..0d523e9fb3d5 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -187,7 +187,7 @@ * /sys/fs/ext4//mb_min_to_scan * /sys/fs/ext4//mb_max_to_scan * /sys/fs/ext4//mb_order2_req - * /sys/fs/ext4//mb_linear_limit + * /sys/fs/ext4//mb_max_linear_groups * * The regular allocator uses buddy scan only if the request len is power of * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The @@ -209,7 +209,7 @@ * get traversed linearly. That may result in subsequent allocations being not * close to each other. And so, the underlying device may get filled up in a * non-linear fashion. While that may not matter on non-rotational devices, for - * rotational devices that may result in higher seek times. "mb_linear_limit" + * rotational devices that may result in higher seek times. "mb_max_linear_groups" * tells mballoc how many groups mballoc should search linearly before * performing consulting above data structures for more efficient lookups. For * non rotational devices, this value defaults to 0 and for rotational devices