Reduce size of zfs_sb_t: allocate z_hold_mtx separately

zfs_sb_t has grown to the point where using kmem_zalloc() for allocations
is triggering the 32k warning threshold.

We can't safely convert this entire allocation to use vmem_alloc() instead
of kmem_alloc() because the backing_dev_info structure is embedded here.
It depends on the bit_waitqueue() function which won't behave properly
when given a virtual address.

Instead, use vmem_alloc() to allocate the z_hold_mtx array separately.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Closes #3178
This commit is contained in:
Chris Dunlop 2015-03-16 12:21:21 +11:00 committed by Brian Behlendorf
parent bc88866657
commit d07b7c7f21
3 changed files with 10 additions and 1 deletions

View File

@ -92,7 +92,7 @@ typedef struct zfs_sb {
uint64_t z_replay_eof; /* New end of file - replay only */ uint64_t z_replay_eof; /* New end of file - replay only */
sa_attr_type_t *z_attr_table; /* SA attr mapping->id */ sa_attr_type_t *z_attr_table; /* SA attr mapping->id */
#define ZFS_OBJ_MTX_SZ 256 #define ZFS_OBJ_MTX_SZ 256
kmutex_t z_hold_mtx[ZFS_OBJ_MTX_SZ]; /* znode hold locks */ kmutex_t *z_hold_mtx; /* znode hold locks */
} zfs_sb_t; } zfs_sb_t;
#define ZFS_SUPER_MAGIC 0x2fc12fc1 #define ZFS_SUPER_MAGIC 0x2fc12fc1

View File

@ -776,6 +776,9 @@ zfs_sb_create(const char *osname, zfs_sb_t **zsbp)
rrw_init(&zsb->z_teardown_lock, B_FALSE); rrw_init(&zsb->z_teardown_lock, B_FALSE);
rw_init(&zsb->z_teardown_inactive_lock, NULL, RW_DEFAULT, NULL); rw_init(&zsb->z_teardown_inactive_lock, NULL, RW_DEFAULT, NULL);
rw_init(&zsb->z_fuid_lock, NULL, RW_DEFAULT, NULL); rw_init(&zsb->z_fuid_lock, NULL, RW_DEFAULT, NULL);
zsb->z_hold_mtx = vmem_zalloc(sizeof (kmutex_t) * ZFS_OBJ_MTX_SZ,
KM_SLEEP);
for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
mutex_init(&zsb->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL); mutex_init(&zsb->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL);
@ -789,6 +792,8 @@ zfs_sb_create(const char *osname, zfs_sb_t **zsbp)
out: out:
dmu_objset_disown(os, zsb); dmu_objset_disown(os, zsb);
*zsbp = NULL; *zsbp = NULL;
vmem_free(zsb->z_hold_mtx, sizeof (kmutex_t) * ZFS_OBJ_MTX_SZ);
kmem_free(zsb, sizeof (zfs_sb_t)); kmem_free(zsb, sizeof (zfs_sb_t));
return (error); return (error);
} }
@ -892,6 +897,7 @@ zfs_sb_free(zfs_sb_t *zsb)
rw_destroy(&zsb->z_fuid_lock); rw_destroy(&zsb->z_fuid_lock);
for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
mutex_destroy(&zsb->z_hold_mtx[i]); mutex_destroy(&zsb->z_hold_mtx[i]);
vmem_free(zsb->z_hold_mtx, sizeof (kmutex_t) * ZFS_OBJ_MTX_SZ);
mutex_destroy(&zsb->z_ctldir_lock); mutex_destroy(&zsb->z_ctldir_lock);
avl_destroy(&zsb->z_ctldir_snaps); avl_destroy(&zsb->z_ctldir_snaps);
kmem_free(zsb, sizeof (zfs_sb_t)); kmem_free(zsb, sizeof (zfs_sb_t));

View File

@ -1731,6 +1731,8 @@ zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
list_create(&zsb->z_all_znodes, sizeof (znode_t), list_create(&zsb->z_all_znodes, sizeof (znode_t),
offsetof(znode_t, z_link_node)); offsetof(znode_t, z_link_node));
zsb->z_hold_mtx = vmem_zalloc(sizeof (kmutex_t) * ZFS_OBJ_MTX_SZ,
KM_SLEEP);
for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
mutex_init(&zsb->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL); mutex_init(&zsb->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL);
@ -1755,6 +1757,7 @@ zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
mutex_destroy(&zsb->z_hold_mtx[i]); mutex_destroy(&zsb->z_hold_mtx[i]);
vmem_free(zsb->z_hold_mtx, sizeof (kmutex_t) * ZFS_OBJ_MTX_SZ);
kmem_free(sb, sizeof (struct super_block)); kmem_free(sb, sizeof (struct super_block));
kmem_free(zsb, sizeof (zfs_sb_t)); kmem_free(zsb, sizeof (zfs_sb_t));
} }