OpenZFS 9465 - ARC check for 'anon_size > arc_c/2' can stall the system

In the case of one pool being built on another pool, we want
to make sure we don't end up throttling the lower (backing)
pool when the upper pool is the majority contributor to dirty
data. To insure we make forward progress during throttling, we
also check the current pool's net dirty data and only throttle
if it exceeds zfs_arc_pool_dirty_percent of the anonymous dirty
data in the cache.

Authored by: Don Brady <[email protected]>
Reviewed by: Sebastien Roy <[email protected]>
Reviewed by: Matt Ahrens <[email protected]>
Reviewed by: Prashanth Sreenivasa <[email protected]>
Approved by: Robert Mustacchi <[email protected]>
Ported-by: Brian Behlendorf <[email protected]>

Porting Notes:
* The new global variables zfs_arc_dirty_limit_percent,
  zfs_arc_anon_limit_percent, and zfs_arc_pool_dirty_percent
  were intentially not added as tunable module parameters.

OpenZFS-issue: https://illumos.org/issues/9465
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d6a4c3ef
Closes #7749

1 files changed, 1 insertions, 1 deletions

diff --git a/include/sys/arc.h b/include/sys/arc.h
index 9d6bab505..a5bdefb56 100644
--- a/include/sys/arc.h
+++ b/include/sys/arc.h
@@ -289,7 +289,7 @@ void arc_freed(spa_t *spa, const blkptr_t *bp);
 
 void arc_flush(spa_t *spa, boolean_t retry);
 void arc_tempreserve_clear(uint64_t reserve);
-int arc_tempreserve_space(uint64_t reserve, uint64_t txg);
+int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg);
 
 uint64_t arc_target_bytes(void);
 void arc_init(void);