diff options
| author | Paul Dagnelie <[email protected]> | 2017-05-25 11:32:40 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2018-06-06 09:35:59 -0700 |
| commit | 37fb3e431845b934df9771d7bcca5fbef79f4c1e (patch) | |
| tree | 352e34819910486a9a5ff9cb8870f4256c90afff /module/zfs/dbuf.c | |
| parent | f0ed6c744872ec6dc4838947ffc597f4d141864a (diff) | |
OpenZFS 8484 - Implement aggregate sum and use for arc counters
In pursuit of improving performance on multi-core systems, we should
implements fanned out counters and use them to improve the performance of
some of the arc statistics. These stats are updated extremely frequently,
and can consume a significant amount of CPU time.
Authored by: Paul Dagnelie <[email protected]>
Reviewed by: Pavel Zakharov <[email protected]>
Reviewed by: Matthew Ahrens <[email protected]>
Approved by: Dan McDonald <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Ported-by: Paul Dagnelie <[email protected]>
OpenZFS-issue: https://www.illumos.org/issues/8484
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7028a8b92b7
Issue #3752
Closes #7462
Diffstat (limited to 'module/zfs/dbuf.c')
| -rw-r--r-- | module/zfs/dbuf.c | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index a8c48167a..6e2f20e50 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -48,6 +48,7 @@ #include <sys/callb.h> #include <sys/abd.h> #include <sys/vdev.h> +#include <sys/cityhash.h> kstat_t *dbuf_ksp; @@ -270,23 +271,14 @@ static dbuf_hash_table_t dbuf_hash_table; static uint64_t dbuf_hash_count; +/* + * We use Cityhash for this. It's fast, and has good hash properties without + * requiring any large static buffers. + */ static uint64_t dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid) { - uintptr_t osv = (uintptr_t)os; - uint64_t crc = -1ULL; - - ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY); - crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (lvl)) & 0xFF]; - crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF]; - crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF]; - crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF]; - crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 0)) & 0xFF]; - crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 8)) & 0xFF]; - - crc ^= (osv>>14) ^ (obj>>16) ^ (blkid>>16); - - return (crc); + return (cityhash4((uintptr_t)os, obj, (uint64_t)lvl, blkid)); } #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \ |