From: Kemeng Shi <shikemeng@huaweicloud.com> mainline inclusion from mainline-v6.10-rc1 commit da5704eef7037a5bc84a56519729d93d10a0e0a0 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ICN2MB Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Open coding repeated check in next_linear_group. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20240424061904.987525-6-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Baokun Li <libaokun1@huawei.com> --- 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 65cdb2c0dfc7..66191ba5d53c 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1114,23 +1114,11 @@ 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. @@ -1156,8 +1144,19 @@ 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; } -- 2.39.2