On Wed 27-03-24 05:38:22, Kemeng Shi wrote:
> Use correct criteria name instead stale integer number in comment
>
> Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Looks good. But since the symbolic names already have CR prefix, we
probably don't have to write e.g.:
/* Large fragment size list lookup succeeded at least once for cr =
* CR_POWER2_ALIGNED */
But we can write directly:
/* Large fragment size list lookup succeeded at least once for
* CR_POWER2_ALIGNED */
Honza
> ---
> fs/ext4/ext4.h | 15 ++++++++++++---
> fs/ext4/mballoc.c | 14 ++++++++------
> fs/ext4/mballoc.h | 4 ++--
> 3 files changed, 22 insertions(+), 11 deletions(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 023571f8dd1b..9b90013c59a3 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -213,11 +213,20 @@ enum criteria {
> #define EXT4_MB_USE_RESERVED 0x2000
> /* Do strict check for free blocks while retrying block allocation */
> #define EXT4_MB_STRICT_CHECK 0x4000
> -/* Large fragment size list lookup succeeded at least once for cr = 0 */
> +/*
> + * Large fragment size list lookup succeeded at least once for cr =
> + * CR_POWER2_ALIGNED
> + */
> #define EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED 0x8000
> -/* Avg fragment size rb tree lookup succeeded at least once for cr = 1 */
> +/*
> + * Avg fragment size rb tree lookup succeeded at least once for cr =
> + * CR_GOAL_LEN_FAST
> + */
> #define EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED 0x00010000
> -/* Avg fragment size rb tree lookup succeeded at least once for cr = 1.5 */
> +/*
> + * Avg fragment size rb tree lookup succeeded at least once for cr =
> + * CR_BEST_AVAIL_LEN
> + */
> #define EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED 0x00020000
>
> struct ext4_allocation_request {
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 62d468379722..0f8a34513bf6 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -1131,8 +1131,9 @@ static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac,
> ext4_mb_choose_next_group_best_avail(ac, new_cr, group);
> } else {
> /*
> - * TODO: For CR=2, we can arrange groups in an rb tree sorted by
> - * bb_free. But until that happens, we should never come here.
> + * TODO: For CR=CR_GOAL_LEN_SLOW, we can arrange groups in an
> + * rb tree sorted by bb_free. But until that happens, we should
> + * never come here.
> */
> WARN_ON(1);
> }
> @@ -3444,10 +3445,11 @@ static int ext4_mb_init_backend(struct super_block *sb)
> }
> if (sbi->s_mb_prefetch > ext4_get_groups_count(sb))
> sbi->s_mb_prefetch = ext4_get_groups_count(sb);
> - /* now many real IOs to prefetch within a single allocation at cr=0
> - * given cr=0 is an CPU-related optimization we shouldn't try to
> - * load too many groups, at some point we should start to use what
> - * we've got in memory.
> + /*
> + * now many real IOs to prefetch within a single allocation at
> + * cr=CR_POWER2_ALIGNED. Given cr=CR_POWER2_ALIGNED is an CPU-related
> + * optimization we shouldn't try to load too many groups, at some point
> + * we should start to use what we've got in memory.
> * with an average random access time 5ms, it'd take a second to get
> * 200 groups (* N with flex_bg), so let's make this limit 4
> */
> diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
> index 56938532b4ce..042437d8860f 100644
> --- a/fs/ext4/mballoc.h
> +++ b/fs/ext4/mballoc.h
> @@ -187,8 +187,8 @@ struct ext4_allocation_context {
> struct ext4_free_extent ac_f_ex;
>
> /*
> - * goal len can change in CR1.5, so save the original len. This is
> - * used while adjusting the PA window and for accounting.
> + * goal len can change in CR_BEST_AVAIL_LEN, so save the original len.
> + * This is used while adjusting the PA window and for accounting.
> */
> ext4_grpblk_t ac_orig_goal_len;
>
> --
> 2.30.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
