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MFV r316860: 7545 zdb should disable reference tracking

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illumos/illumos-gate@4dd77f9e38
4dd77f9e38

https://www.illumos.org/issues/7545
  When evicting from the ARC, we manipulate some refcount_t's, e.g. arcs_size.
  When using zdb to examine a large amount of data (e.g. zdb -bb on a large pool
  with small blocks), the ARC may have a large number of entries. If reference
  tracking is enabled, there will be ~1 reference for each block in the ARC. When
  evicting, we decrement the refcount and have to search all the references to
  find the one that we are removing, which is very slow.
  Since zdb is typically used to find problems with the on-disk format, and not
  with the code it is running, we should disable reference tracking in zdb.

Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Steve Gonczi <steve.gonczi@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>

MFC after:	2 weeks
This commit is contained in:
avg 2017-05-24 20:41:26 +00:00
parent 330705f598
commit 980be3f7ab
1 changed files with 7 additions and 0 deletions
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7
cddl/contrib/opensolaris/cmd/zdb/zdb.c
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@ -75,10 +75,12 @@
DMU_OT_ZAP_OTHER : DMU_OT_NUMTYPES))
#ifndef lint
extern int reference_tracking_enable;
extern boolean_t zfs_recover;
extern uint64_t zfs_arc_max, zfs_arc_meta_limit;
extern int zfs_vdev_async_read_max_active;
#else
int reference_tracking_enable;
boolean_t zfs_recover;
uint64_t zfs_arc_max, zfs_arc_meta_limit;
int zfs_vdev_async_read_max_active;
@ -3696,6 +3698,11 @@ main(int argc, char **argv)
*/
zfs_vdev_async_read_max_active = 10;
/*
* Disable reference tracking for better performance.
*/
reference_tracking_enable = B_FALSE;
kernel_init(FREAD);
g_zfs = libzfs_init();
if (g_zfs == NULL)