diff options
| author | Alexander Motin <[email protected]> | 2023-10-04 17:45:00 -0400 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2023-10-07 09:08:20 -0700 |
| commit | bc77a0c85ec9a26452992421f738dee0a786322b (patch) | |
| tree | c9a593b94b962468168d1d0139a1cb8c7405422f /module/zfs | |
| parent | 1611b8e56e555bf928b795e45ba1724ef85eb1ed (diff) | |
ARC: Remove b_cv from struct l1arc_buf_hdr
Earlier as part of #14123 I've removed one use of b_cv. This patch
reuses the same approach to remove the other one from much more
rare code path.
This saves 16 bytes of L1 ARC header on FreeBSD (reducing it from
200 to 184 bytes) and seems even more on Linux.
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Alexander Motin <[email protected]>
Sponsored by: iXsystems, Inc.
Closes #15340
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/arc.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 22dc0ed5e..919684a58 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -1151,7 +1151,6 @@ hdr_full_cons(void *vbuf, void *unused, int kmflag) memset(hdr, 0, HDR_FULL_SIZE); hdr->b_l1hdr.b_byteswap = DMU_BSWAP_NUMFUNCS; - cv_init(&hdr->b_l1hdr.b_cv, NULL, CV_DEFAULT, NULL); zfs_refcount_create(&hdr->b_l1hdr.b_refcnt); #ifdef ZFS_DEBUG mutex_init(&hdr->b_l1hdr.b_freeze_lock, NULL, MUTEX_DEFAULT, NULL); @@ -1211,7 +1210,6 @@ hdr_full_dest(void *vbuf, void *unused) arc_buf_hdr_t *hdr = vbuf; ASSERT(HDR_EMPTY(hdr)); - cv_destroy(&hdr->b_l1hdr.b_cv); zfs_refcount_destroy(&hdr->b_l1hdr.b_refcnt); #ifdef ZFS_DEBUG mutex_destroy(&hdr->b_l1hdr.b_freeze_lock); @@ -5586,13 +5584,6 @@ arc_read_done(zio_t *zio) buf_hash_remove(hdr); } - /* - * Broadcast before we drop the hash_lock to avoid the possibility - * that the hdr (and hence the cv) might be freed before we get to - * the cv_broadcast(). - */ - cv_broadcast(&hdr->b_l1hdr.b_cv); - arc_hdr_clear_flags(hdr, ARC_FLAG_IO_IN_PROGRESS); (void) remove_reference(hdr, hdr); @@ -5787,8 +5778,7 @@ top: } acb->acb_zio_head = head_zio; acb->acb_next = hdr->b_l1hdr.b_acb; - if (hdr->b_l1hdr.b_acb) - hdr->b_l1hdr.b_acb->acb_prev = acb; + hdr->b_l1hdr.b_acb->acb_prev = acb; hdr->b_l1hdr.b_acb = acb; } mutex_exit(hash_lock); @@ -5928,8 +5918,28 @@ top: * and so the performance impact shouldn't * matter. */ - cv_wait(&hdr->b_l1hdr.b_cv, hash_lock); + arc_callback_t *acb = kmem_zalloc( + sizeof (arc_callback_t), KM_SLEEP); + acb->acb_wait = B_TRUE; + mutex_init(&acb->acb_wait_lock, NULL, + MUTEX_DEFAULT, NULL); + cv_init(&acb->acb_wait_cv, NULL, CV_DEFAULT, + NULL); + acb->acb_zio_head = + hdr->b_l1hdr.b_acb->acb_zio_head; + acb->acb_next = hdr->b_l1hdr.b_acb; + hdr->b_l1hdr.b_acb->acb_prev = acb; + hdr->b_l1hdr.b_acb = acb; mutex_exit(hash_lock); + mutex_enter(&acb->acb_wait_lock); + while (acb->acb_wait) { + cv_wait(&acb->acb_wait_cv, + &acb->acb_wait_lock); + } + mutex_exit(&acb->acb_wait_lock); + mutex_destroy(&acb->acb_wait_lock); + cv_destroy(&acb->acb_wait_cv); + kmem_free(acb, sizeof (arc_callback_t)); goto top; } } |