linux/fs/ext4
Jan Kara 4a79a98c7b ext4: Improve scalability of ext4 orphan file handling
Even though the length of the critical section when adding / removing
orphaned inodes was significantly reduced by using orphan file, the
contention of lock protecting orphan file still appears high in profiles
for truncate / unlink intensive workloads with high number of threads.

This patch makes handling of orphan file completely lockless. Also to
reduce conflicts between CPUs different CPUs start searching for empty
slot in orphan file in different blocks.

Performance comparison of locked orphan file handling, lockless orphan
file handling, and completely disabled orphan inode handling
from 80 CPU Xeon Server with 526 GB of RAM, filesystem located on
SAS SSD disk, average of 5 runs:

stress-orphan (microbenchmark truncating files byte-by-byte from N
processes in parallel)

Threads Time            Time            Time
        Orphan locked   Orphan lockless No orphan
  1       0.945600       0.939400        0.891200
  2       1.331800       1.246600        1.174400
  4       1.995000       1.780600        1.713200
  8       6.424200       4.900000        4.106000
 16      14.937600       8.516400        8.138000
 32      33.038200      24.565600       24.002200
 64      60.823600      39.844600       38.440200
128     122.941400      70.950400       69.315000

So we can see that with lockless orphan file handling, addition /
deletion of orphaned inodes got almost completely out of picture even
for a microbenchmark stressing it.

For reaim creat_clo workload on ramdisk there are also noticeable gains
(average of 5 runs):

Clients         Vanilla (ops/s)        Patched (ops/s)
creat_clo-1     14705.88 (   0.00%)    14354.07 *  -2.39%*
creat_clo-3     27108.43 (   0.00%)    28301.89 (   4.40%)
creat_clo-5     37406.48 (   0.00%)    45180.73 *  20.78%*
creat_clo-7     41338.58 (   0.00%)    54687.50 *  32.29%*
creat_clo-9     45226.13 (   0.00%)    62937.07 *  39.16%*
creat_clo-11    44000.00 (   0.00%)    65088.76 *  47.93%*
creat_clo-13    36516.85 (   0.00%)    68661.97 *  88.03%*
creat_clo-15    30864.20 (   0.00%)    69551.78 * 125.35%*
creat_clo-17    27478.45 (   0.00%)    67729.08 * 146.48%*
creat_clo-19    25000.00 (   0.00%)    61621.62 * 146.49%*
creat_clo-21    18772.35 (   0.00%)    63829.79 * 240.02%*
creat_clo-23    16698.94 (   0.00%)    61938.96 * 270.92%*
creat_clo-25    14973.05 (   0.00%)    56947.61 * 280.33%*
creat_clo-27    16436.69 (   0.00%)    65008.03 * 295.51%*
creat_clo-29    13949.01 (   0.00%)    69047.62 * 395.00%*
creat_clo-31    14283.52 (   0.00%)    67982.45 * 375.95%*

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210816095713.16537-5-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30 23:36:51 -04:00
..
.kunitconfig ext4: add .kunitconfig fragment to enable ext4-specific tests 2021-02-11 23:16:30 -05:00
acl.c ext4: support idmapped mounts 2021-01-24 14:43:46 +01:00
acl.h fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
balloc.c ext4: flush background discard kwork when retry allocation 2021-08-30 23:35:53 -04:00
bitmap.c
block_validity.c ext4: standardize error message in ext4_protect_reserved_inode() 2020-12-17 13:30:55 -05:00
dir.c ext4: handle casefolding with encryption 2021-04-05 22:04:20 -04:00
ext4_extents.h ext4: fix sparse warnings 2021-08-30 23:36:50 -04:00
ext4_jbd2.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
ext4_jbd2.h ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
ext4.h ext4: Improve scalability of ext4 orphan file handling 2021-08-30 23:36:51 -04:00
extents_status.c ext4: correct the cache_nr in tracepoint ext4_es_shrink_exit 2021-06-22 21:34:17 -04:00
extents_status.h ext4: fix extent_status trace points 2020-01-25 02:03:03 -05:00
extents.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
fast_commit.c ext4: reduce arguments of ext4_fc_add_dentry_tlv 2021-08-30 23:36:50 -04:00
fast_commit.h ext4: fix fast commit alignment issues 2021-06-06 10:10:23 -04:00
file.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
fsmap.c treewide: Change list_sort to use const pointers 2021-04-08 16:04:22 -07:00
fsmap.h ext4: fsmap: fix the block/inode bitmap comment 2021-06-24 09:48:29 -04:00
fsync.c block: use an on-stack bio in blkdev_issue_flush 2021-01-27 09:51:48 -07:00
hash.c ext4: handle casefolding with encryption 2021-04-05 22:04:20 -04:00
ialloc.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
indirect.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
inline.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
inode-test.c fs: ext4: Modify inode-test.c to use KUnit parameterized testing feature 2020-12-02 16:07:25 -07:00
inode.c ext4: Speedup ext4 orphan inode handling 2021-08-30 23:36:51 -04:00
ioctl.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
Kconfig ext: EXT4_KUNIT_TESTS should depend on EXT4_FS instead of selecting it 2021-02-11 23:12:59 -05:00
Makefile ext4: Move orphan inode handling into a separate file 2021-08-30 23:36:51 -04:00
mballoc.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
mballoc.h ext4: fix various seppling typos 2021-04-09 23:14:59 -04:00
migrate.c ext4: fix various seppling typos 2021-04-09 23:14:59 -04:00
mmp.c ext4: fix potential uninitialized access to retval in kmmpd 2021-07-23 07:31:29 -04:00
move_extent.c ext4: use common helpers in all places reading metadata buffers 2020-10-18 10:37:14 -04:00
namei.c ext4: Move orphan inode handling into a separate file 2021-08-30 23:36:51 -04:00
orphan.c ext4: Improve scalability of ext4 orphan file handling 2021-08-30 23:36:51 -04:00
page-io.c block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
readpage.c block: Add bio_max_segs 2021-02-26 15:49:51 -07:00
resize.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
super.c ext4: Speedup ext4 orphan inode handling 2021-08-30 23:36:51 -04:00
symlink.c
sysfs.c ext4: notify sysfs on errors_count value change 2021-06-29 21:06:02 -04:00
truncate.h ext4: handle layout changes to pinned DAX mappings 2018-07-29 17:00:22 -04:00
verity.c New features for ext4 this cycle include support for encrypted 2021-04-30 15:35:30 -07:00
xattr_hurd.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_security.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_trusted.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_user.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr.c ext4: Support for checksumming from journal triggers 2021-08-30 23:36:50 -04:00
xattr.h ext4: remove duplicate definition of ext4_xattr_ibody_inline_set() 2021-06-24 10:09:39 -04:00