diff options
| author | Max Grossman <[email protected]> | 2014-09-07 17:06:08 +0200 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2014-09-23 14:26:34 -0700 |
| commit | 36283ca23346061cb653dc7b6bd583d1cf772808 (patch) | |
| tree | fa84ff76b97a14142e4b965f26415d6f16bf2e8f | |
| parent | acbad6ff6768b0ccfb3c319e981ec211dcecc277 (diff) | |
Illumos 5138 - add tunable for maximum number of blocks freed in one txg
Reviewed by: Adam Leventhal <[email protected]>
Reviewed by: Mattew Ahrens <[email protected]>
Reviewed by: Josef 'Jeff' Sipek <[email protected]>
Reviewed by: Richard Elling <[email protected]>
Reviewed by: George Wilson <[email protected]>
Approved by: Dan McDonald <[email protected]>
References:
https://www.illumos.org/issues/5138
https://github.com/illumos/illumos-gate/commit/af3465d
Porting notes:
Because support for exposing a uint64_t parameter wasn't added
until v3.17-rc1 the zfs_free_max_blocks variable has been declared
as a unsigned long. This is already far larger than required and
it allows us to avoid additional autoconf compatibility code.
The default value has been set to 100,000 on Linux instead of
ULONG_MAX which is used on Illumos. This was done to limit the
number of outstanding IOs in the system when snapshots are destroyed.
This helps ensure individual TXG sync times are kept reasonable and
memory isn't wasted managing a huge backlog of outstanding IOs.
Ported by: Turbo Fredriksson <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2675
Closes #2581
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 11 | ||||
| -rw-r--r-- | module/zfs/dsl_scan.c | 8 |
2 files changed, 19 insertions, 0 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 9c5d70de8..28c6e11d2 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -623,6 +623,17 @@ Default value: \fB67,108,864\fR. .sp .ne 2 .na +\fBzfs_free_max_blocks\fR (ulong) +.ad +.RS 12n +Maximum number of blocks freed in a single txg. +.sp +Default value: \fB100,000\fR. +.RE + +.sp +.ne 2 +.na \fBzfs_vdev_async_read_max_active\fR (int) .ad .RS 12n diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c index 5546dad5f..eeec76f78 100644 --- a/module/zfs/dsl_scan.c +++ b/module/zfs/dsl_scan.c @@ -69,6 +69,8 @@ int zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */ int zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */ enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; int dsl_scan_delay_completion = B_FALSE; /* set to delay scan completion */ +/* max number of blocks to free in a single TXG */ +ulong zfs_free_max_blocks = 100000; #define DSL_SCAN_IS_SCRUB_RESILVER(scn) \ ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \ @@ -1370,6 +1372,9 @@ dsl_scan_free_should_pause(dsl_scan_t *scn) if (zfs_recover) return (B_FALSE); + if (scn->scn_visited_this_txg >= zfs_free_max_blocks) + return (B_TRUE); + elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && @@ -1868,4 +1873,7 @@ MODULE_PARM_DESC(zfs_no_scrub_io, "Set to disable scrub I/O"); module_param(zfs_no_scrub_prefetch, int, 0644); MODULE_PARM_DESC(zfs_no_scrub_prefetch, "Set to disable scrub prefetching"); + +module_param(zfs_free_max_blocks, ulong, 0644); +MODULE_PARM_DESC(zfs_free_max_blocks, "Max number of blocks freed in one txg"); #endif |