diff options
| author | Jan Kara <jack@suse.cz> | 2021-08-16 12:57:08 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2021-08-31 06:36:51 +0300 |
| commit | 4a79a98c7b19dd3d4cfe9200fbc384ba9119e039 (patch) | |
| tree | 85a3fa57a42cbd80394058461312c9c007525f96 /fs/ext4/ext4.h | |
| parent | 3a6541e97c035dba90cdf37169d73b2d8057e55d (diff) | |
| download | linux-4a79a98c7b19dd3d4cfe9200fbc384ba9119e039.tar.xz | |
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>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index ae79797b9d60..98758e8ea7fc 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1489,7 +1489,7 @@ static inline int ext4_inodes_per_orphan_block(struct super_block *sb) } struct ext4_orphan_block { - int ob_free_entries; /* Number of free orphan entries in block */ + atomic_t ob_free_entries; /* Number of free orphan entries in block */ struct buffer_head *ob_bh; /* Buffer for orphan block */ }; @@ -1497,7 +1497,6 @@ struct ext4_orphan_block { * Info about orphan file. */ struct ext4_orphan_info { - spinlock_t of_lock; int of_blocks; /* Number of orphan blocks in a file */ __u32 of_csum_seed; /* Checksum seed for orphan file */ struct ext4_orphan_block *of_binfo; /* Array with info about orphan |