| Message ID | 20240423124046.974134-6-shikemeng@huaweicloud.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Minor improvements and cleanups to ext4 mballoc | expand |
On Tue 23-04-24 20:40:46, Kemeng Shi wrote: > Open coding repeated check in next_linear_group. > > Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/mballoc.c | 31 +++++++++++++++---------------- > 1 file changed, 15 insertions(+), 16 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 71b2f9a18875..4afe5bb94bf4 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -1076,23 +1076,11 @@ static inline int should_optimize_scan(struct ext4_allocation_context *ac) > } > > /* > - * Return next linear group for allocation. If linear traversal should not be > - * performed, this function just returns the same group > + * Return next linear group for allocation. > */ > static ext4_group_t > -next_linear_group(struct ext4_allocation_context *ac, ext4_group_t group, > - ext4_group_t ngroups) > +next_linear_group(ext4_group_t group, ext4_group_t ngroups) > { > - if (!should_optimize_scan(ac)) > - goto inc_and_return; > - > - if (ac->ac_groups_linear_remaining) { > - ac->ac_groups_linear_remaining--; > - goto inc_and_return; > - } > - > - return group; > -inc_and_return: > /* > * Artificially restricted ngroups for non-extent > * files makes group > ngroups possible on first loop. > @@ -1118,8 +1106,19 @@ static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac, > { > *new_cr = ac->ac_criteria; > > - if (!should_optimize_scan(ac) || ac->ac_groups_linear_remaining) { > - *group = next_linear_group(ac, *group, ngroups); > + if (!should_optimize_scan(ac)) { > + *group = next_linear_group(*group, ngroups); > + return; > + } > + > + /* > + * Optimized scanning can return non adjacent groups which can cause > + * seek overhead for rotational disks. So try few linear groups before > + * trying optimized scan. > + */ > + if (ac->ac_groups_linear_remaining) { > + *group = next_linear_group(*group, ngroups); > + ac->ac_groups_linear_remaining--; > return; > } > > -- > 2.30.0 >
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 71b2f9a18875..4afe5bb94bf4 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1076,23 +1076,11 @@ static inline int should_optimize_scan(struct ext4_allocation_context *ac) } /* - * Return next linear group for allocation. If linear traversal should not be - * performed, this function just returns the same group + * Return next linear group for allocation. */ static ext4_group_t -next_linear_group(struct ext4_allocation_context *ac, ext4_group_t group, - ext4_group_t ngroups) +next_linear_group(ext4_group_t group, ext4_group_t ngroups) { - if (!should_optimize_scan(ac)) - goto inc_and_return; - - if (ac->ac_groups_linear_remaining) { - ac->ac_groups_linear_remaining--; - goto inc_and_return; - } - - return group; -inc_and_return: /* * Artificially restricted ngroups for non-extent * files makes group > ngroups possible on first loop. @@ -1118,8 +1106,19 @@ static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac, { *new_cr = ac->ac_criteria; - if (!should_optimize_scan(ac) || ac->ac_groups_linear_remaining) { - *group = next_linear_group(ac, *group, ngroups); + if (!should_optimize_scan(ac)) { + *group = next_linear_group(*group, ngroups); + return; + } + + /* + * Optimized scanning can return non adjacent groups which can cause + * seek overhead for rotational disks. So try few linear groups before + * trying optimized scan. + */ + if (ac->ac_groups_linear_remaining) { + *group = next_linear_group(*group, ngroups); + ac->ac_groups_linear_remaining--; return; }
Open coding repeated check in next_linear_group. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> --- fs/ext4/mballoc.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-)