Added kernel patch 2 to improve fallocate performance
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/fs/ext4/mballoc.c?id=40ae3487628235e5f1eb27542cca0cdb6e5dbe16
Change-Id: I079e9af8974f4ab5e4f35d1e5ddfa955e05310f7
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 1d07c12..58f89b3 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1928,15 +1928,19 @@
case 0:
BUG_ON(ac->ac_2order == 0);
- if (grp->bb_largest_free_order < ac->ac_2order)
- return 0;
-
/* Avoid using the first bg of a flexgroup for data files */
if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
(flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
((group % flex_size) == 0))
return 0;
+ if ((ac->ac_2order > ac->ac_sb->s_blocksize_bits+1) ||
+ (free / fragments) >= ac->ac_g_ex.fe_len)
+ return 1;
+
+ if (grp->bb_largest_free_order < ac->ac_2order)
+ return 0;
+
return 1;
case 1:
if ((free / fragments) >= ac->ac_g_ex.fe_len)
@@ -2051,7 +2055,7 @@
}
ac->ac_groups_scanned++;
- if (cr == 0)
+ if (cr == 0 && ac->ac_2order < sb->s_blocksize_bits+2)
ext4_mb_simple_scan_group(ac, &e4b);
else if (cr == 1 && sbi->s_stripe &&
!(ac->ac_g_ex.fe_len % sbi->s_stripe))
@@ -4046,8 +4050,8 @@
len = ar->len;
/* just a dirty hack to filter too big requests */
- if (len >= EXT4_CLUSTERS_PER_GROUP(sb) - 10)
- len = EXT4_CLUSTERS_PER_GROUP(sb) - 10;
+ if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
+ len = EXT4_CLUSTERS_PER_GROUP(sb);
/* start searching from the goal */
goal = ar->goal;
