ldiskfs/kernel_patches/patches/rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

   1 --- linux-4.18/fs/ext4/mballoc.c        2019-11-28 14:55:26.500545920 +0300
   2 +++ linux-4.18/fs/ext4/mballoc.c        2019-11-28 14:53:18.600086008 +0300
   3 @@ -2060,7 +2060,15 @@ static int ext4_mb_good_group(struct
   4
   5         /* We only do this if the grp has never been initialized */
   6         if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
   7 -               int ret = ext4_mb_init_group(ac->ac_sb, group);
   8 +               int ret;
   9 +
  10 +               /* cr=0/1 is a very optimistic search to find large
  11 +                * good chunks almost for free. if buddy data is
  12 +                * not ready, then this optimization makes no sense */
  13 +
  14 +               if (cr < 2)
  15 +                       return 0;
  16 +               ret = ext4_mb_init_group(ac->ac_sb, group);
  17                 if (ret)
  18                         return ret;
  19         }