ext4: Use struct flex_groups to calculate get_orlov_stats()
Instead of looping over all of the block groups in a flex group
summing their summary statistics, start tracking used_dirs in struct
flex_groups, and use struct flex_groups instead. This should save a
bit of CPU for mkdir-heavy workloads.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 5f39392..47b84e8 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -267,6 +267,13 @@
if (is_directory) {
count = ext4_used_dirs_count(sb, gdp) - 1;
ext4_used_dirs_set(sb, gdp, count);
+ if (sbi->s_log_groups_per_flex) {
+ ext4_group_t f;
+
+ f = ext4_flex_group(sbi, block_group);
+ atomic_dec(&sbi->s_flex_groups[f].free_inodes);
+ }
+
}
gdp->bg_checksum = ext4_group_desc_csum(sbi,
block_group, gdp);
@@ -424,25 +431,24 @@
int flex_size, struct orlov_stats *stats)
{
struct ext4_group_desc *desc;
- ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
- int i;
+ struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
- stats->free_inodes = 0;
- stats->free_blocks = 0;
- stats->used_dirs = 0;
+ if (flex_size > 1) {
+ stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
+ stats->free_blocks = atomic_read(&flex_group[g].free_blocks);
+ stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
+ return;
+ }
- g *= flex_size;
-
- for (i = 0; i < flex_size; i++) {
- if (g >= ngroups)
- break;
- desc = ext4_get_group_desc(sb, g++, NULL);
- if (!desc)
- continue;
-
- stats->free_inodes += ext4_free_inodes_count(sb, desc);
- stats->free_blocks += ext4_free_blks_count(sb, desc);
- stats->used_dirs += ext4_used_dirs_count(sb, desc);
+ desc = ext4_get_group_desc(sb, g, NULL);
+ if (desc) {
+ stats->free_inodes = ext4_free_inodes_count(sb, desc);
+ stats->free_blocks = ext4_free_blks_count(sb, desc);
+ stats->used_dirs = ext4_used_dirs_count(sb, desc);
+ } else {
+ stats->free_inodes = 0;
+ stats->free_blocks = 0;
+ stats->used_dirs = 0;
}
}
@@ -765,6 +771,11 @@
if (S_ISDIR(mode)) {
count = ext4_used_dirs_count(sb, gdp) + 1;
ext4_used_dirs_set(sb, gdp, count);
+ if (sbi->s_log_groups_per_flex) {
+ ext4_group_t f = ext4_flex_group(sbi, group);
+
+ atomic_inc(&sbi->s_flex_groups[f].free_inodes);
+ }
}
gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
err_ret: