Add zfs_object_mutex_size module option

Add a zfs_object_mutex_size module option to facilitate resizing the
the per-dataset znode mutex array.  Increasing this value may help
make the deadlock described in #4106 less common, but this is not a
proper fix.  This patch is primarily to aid debugging and analysis.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #4106
This commit is contained in:
Brian Behlendorf
2015-12-18 12:19:14 -08:00
parent d21f279a94
commit 0720116d4d
4 changed files with 26 additions and 12 deletions
+1 -1
View File
@@ -112,7 +112,7 @@ typedef struct zfs_sb {
uint64_t z_groupquota_obj;
uint64_t z_replay_eof; /* New end of file - replay only */
sa_attr_type_t *z_attr_table; /* SA attr mapping->id */
#define ZFS_OBJ_MTX_SZ 256
uint64_t z_hold_mtx_size; /* znode hold locks size */
kmutex_t *z_hold_mtx; /* znode hold locks */
} zfs_sb_t;
+8 -2
View File
@@ -273,9 +273,15 @@ typedef struct znode {
/*
* Macros for dealing with dmu_buf_hold
*/
#define ZFS_OBJ_HASH(obj_num) ((obj_num) & (ZFS_OBJ_MTX_SZ - 1))
#define ZFS_OBJ_MTX_SZ 64
#define ZFS_OBJ_MTX_MAX (1024 * 1024)
extern unsigned int zfs_object_mutex_size;
#define ZFS_OBJ_HASH(zsb, obj_num) \
((obj_num) & ((zsb->z_hold_mtx_size) - 1))
#define ZFS_OBJ_MUTEX(zsb, obj_num) \
(&(zsb)->z_hold_mtx[ZFS_OBJ_HASH(obj_num)])
(&(zsb)->z_hold_mtx[ZFS_OBJ_HASH(zsb, obj_num)])
#define ZFS_OBJ_HOLD_ENTER(zsb, obj_num) \
mutex_enter(ZFS_OBJ_MUTEX((zsb), (obj_num)))
#define ZFS_OBJ_HOLD_TRYENTER(zsb, obj_num) \