LU-12988 ldiskfs: skip non-loaded groups at cr=0/1

cr=0 is supposed to be an optimization to save CPU cycles,
but if buddy data (in memory) is not initialized then all
this makes no sense as we have to do sync IO taking a lot
of cycles.  also, at cr=0 mballoc doesn't store any avaibale
chunk. cr=1 also skips groups using heruistic based on avg.
fragment size.
it's more useful to skip such groups and switch to cr=2 where
groups will be scanned for available chunks.

using sparse image and dm-slow virtual device of 120TB was
simulated. then the image was formatted as OST and filled
using debugfs to mark ~85% of available space as busy.
mount as OST w/o the patch couldn't complete in half an hour
(according to vmstat it would take ~10-11 hours). with the
patch applied mount took ~20 seconds.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I88c8c1b01b386af0fa438bfeb97acb6110bd00ec
Reviewed-on: https://review.whamcloud.com/36891
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: Artem Blagodarenko <c17828@cray.com>

diff --git a/ldiskfs/kernel_patches/patches/rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch b/ldiskfs/kernel_patches/patches/rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch
new file mode 100644 (file)
index 0000000..1bb8398
--- /dev/null
+++ b/ldiskfs/kernel_patches/patches/rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch
@@ -0,0 +1,19 @@
+--- linux-4.18/fs/ext4/mballoc.c       2019-11-28 14:55:26.500545920 +0300
++++ linux-4.18/fs/ext4/mballoc.c       2019-11-28 14:53:18.600086008 +0300
+@@ -2060,7 +2060,15 @@ static int ext4_mb_good_group(struct
+ 
+       /* We only do this if the grp has never been initialized */
+       if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
+-              int ret = ext4_mb_init_group(ac->ac_sb, group);
++              int ret;
++
++              /* cr=0/1 is a very optimistic search to find large
++               * good chunks almost for free. if buddy data is
++               * not ready, then this optimization makes no sense */
++
++              if (cr < 2)
++                      return 0;
++              ret = ext4_mb_init_group(ac->ac_sb, group);
+               if (ret)
+                       return ret;
+       }

diff --git a/ldiskfs/kernel_patches/patches/rhel8/ext4-mballoc-skip-uninit-groups-cr0.patch b/ldiskfs/kernel_patches/patches/rhel8/ext4-mballoc-skip-uninit-groups-cr0.patch
new file mode 100644 (file)
index 0000000..38925ac
--- /dev/null
+++ b/ldiskfs/kernel_patches/patches/rhel8/ext4-mballoc-skip-uninit-groups-cr0.patch
@@ -0,0 +1,19 @@
+--- linux-4.18/fs/ext4/mballoc.c       2019-11-28 14:55:26.500545920 +0300
++++ linux-4.18/fs/ext4/mballoc.c       2019-11-28 14:53:18.600086008 +0300
+@@ -2060,7 +2060,15 @@ static int ext4_mb_good_group(struct
+ 
+       /* We only do this if the grp has never been initialized */
+       if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
+-              int ret = ext4_mb_init_group(ac->ac_sb, group, GFP_NOFS);
++              int ret;
++
++              /* cr=0/1 is a very optimistic search to find large
++               * good chunks almost for free. if buddy data is
++               * not ready, then this optimization makes no sense */
++
++              if (cr < 2)
++                      return 0;
++              ret = ext4_mb_init_group(ac->ac_sb, group, GFP_NOFS);
+               if (ret)
+                       return ret;
+       }

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.2.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.2.series
index 1588268..3948c95 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.2.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.2.series
@@ -37,3 +37,4 @@ rhel7/ext4-export-orphan-add.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.3.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.3.series
index ca71367..c0d41d9 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.3.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.3.series
@@ -37,3 +37,4 @@ rhel7/ext4-export-orphan-add.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.4.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.4.series
index 89fdbc2..906c6f5 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.4.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.4.series
@@ -37,3 +37,4 @@ rhel7/ext4-export-orphan-add.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.5.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.5.series
index f6b3552..5be93d7 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.5.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.5.series
@@ -37,3 +37,4 @@ rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7.2/ext4-export-mb-stream-allocator-variables.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7.2/ext4-export-mb-stream-allocator-variables.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.6.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.6.series
index bcca593..4602afa 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.6.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.6.series
@@ -38,3 +38,4 @@ rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inode
 rhel7.2/ext4-export-mb-stream-allocator-variables.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7.2/ext4-simple-blockalloc.patch
 rhel7.2/ext4-export-mb-stream-allocator-variables.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7.2/ext4-simple-blockalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.7.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.7.series
index d564fc0..db81695 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.7.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.7.series
@@ -38,3 +38,4 @@ rhel7.2/ext4-export-mb-stream-allocator-variables.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7.7/ext4-fix-project-with-unpatched-kernel.patch
 rhel7.2/ext4-simple-blockalloc.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7.7/ext4-fix-project-with-unpatched-kernel.patch
 rhel7.2/ext4-simple-blockalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.series b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.series
index d5d372b..cf7f31d 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-3.10-rhel7.series
@@ -32,3 +32,4 @@ rhel7/ext4-export-orphan-add.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch
 rhel7/ext4-mmp-dont-mark-bh-dirty.patch
 rhel7/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel7/ext4-optimize-ext4_find_delalloc_range-in-nodelalloc.patch

+rhel7/ext4-mballoc-skip-uninit-groups-cr0.patch

diff --git a/ldiskfs/kernel_patches/series/ldiskfs-4.18-rhel8.series b/ldiskfs/kernel_patches/series/ldiskfs-4.18-rhel8.series
index b5b98a3..adcca20 100644 (file)
--- a/ldiskfs/kernel_patches/series/ldiskfs-4.18-rhel8.series
+++ b/ldiskfs/kernel_patches/series/ldiskfs-4.18-rhel8.series
@@ -22,3 +22,4 @@ rhel7/ext4-export-orphan-add.patch
 ubuntu18/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel8/ext4-export-mb-stream-allocator-variables.patch
 rhel8/ext4-simple-blockalloc.patch
 ubuntu18/ext4-include-terminating-u32-in-size-of-xattr-entries-when-expanding-inodes.patch
 rhel8/ext4-export-mb-stream-allocator-variables.patch
 rhel8/ext4-simple-blockalloc.patch

+rhel8/ext4-mballoc-skip-uninit-groups-cr0.patch