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authorChris Wedgwood <[email protected]>2014-10-23 16:00:41 -0700
committerBrian Behlendorf <[email protected]>2014-11-14 14:59:21 -0800
commitb31d8ea77cd91dce29acf3ec448180f3715cca13 (patch)
treec791566449c3affd1e274df2ced107a1655f2875 /include/sys/dbuf.h
parent0f69910833f4918283bad1ce9e23b701fc6edb6b (diff)
Reduce buf/dbuf mutex contention
Due to evidence of contention both the buf_hash_table and the dbuf_hash_table sizes have been increased from 256 to 8192. This increase in hash table size adds approximating 0.5M to our fixed memory footprint. This relatively small increase is not expected to cause problems even on low memory machines. This footprint will also become dynamic when the persistent L2ARC support is finalized. In the meanwhile, this small change significantly reduces contention for certain workloads. Signed-off-by: Chris Wedgwood <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Pavel Snajdr <[email protected]> Closes #1291
Diffstat (limited to 'include/sys/dbuf.h')
-rw-r--r--include/sys/dbuf.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/sys/dbuf.h b/include/sys/dbuf.h
index 76daea90e..af509ca38 100644
--- a/include/sys/dbuf.h
+++ b/include/sys/dbuf.h
@@ -233,7 +233,7 @@ typedef struct dmu_buf_impl {
} dmu_buf_impl_t;
/* Note: the dbuf hash table is exposed only for the mdb module */
-#define DBUF_MUTEXES 256
+#define DBUF_MUTEXES 8192
#define DBUF_HASH_MUTEX(h, idx) (&(h)->hash_mutexes[(idx) & (DBUF_MUTEXES-1)])
typedef struct dbuf_hash_table {
uint64_t hash_table_mask;