diff options
| author | Alexander Motin <[email protected]> | 2023-06-05 14:51:44 -0400 |
|---|---|---|
| committer | GitHub <[email protected]> | 2023-06-05 11:51:44 -0700 |
| commit | 5ba4025a8d94699d2638938a0cdf790113ff0531 (patch) | |
| tree | 12839b3feb9a8b4f5502798317b5a9e91da6d649 /module/zfs | |
| parent | dae3c549f59a4650edd07b86707166765c240310 (diff) | |
Introduce zfs_refcount_(add|remove)_few().
There are two places where we need to add/remove several references
with semantics of zfs_refcount_(add|remove). But when debug/tracing
is disabled, it is a crime to run multiple atomic_inc() in a loop,
especially under congested pool-wide allocator lock.
Introduced new functions implement the same semantics as the loop,
but without overhead in production builds.
Reviewed-by: Rich Ercolani <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Alexander Motin <[email protected]>
Sponsored by: iXsystems, Inc.
Closes #14934
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/dmu_zfetch.c | 3 | ||||
| -rw-r--r-- | module/zfs/metaslab.c | 6 | ||||
| -rw-r--r-- | module/zfs/refcount.c | 18 |
3 files changed, 21 insertions, 6 deletions
diff --git a/module/zfs/dmu_zfetch.c b/module/zfs/dmu_zfetch.c index ffc012e6c..b70459380 100644 --- a/module/zfs/dmu_zfetch.c +++ b/module/zfs/dmu_zfetch.c @@ -520,8 +520,7 @@ dmu_zfetch_run(zstream_t *zs, boolean_t missed, boolean_t have_lock) issued = pf_end - pf_start + ipf_end - ipf_start; if (issued > 1) { /* More references on top of taken in dmu_zfetch_prepare(). */ - for (int i = 0; i < issued - 1; i++) - zfs_refcount_add(&zs->zs_refs, NULL); + zfs_refcount_add_few(&zs->zs_refs, issued - 1, NULL); } else if (issued == 0) { /* Some other thread has done our work, so drop the ref. */ if (zfs_refcount_remove(&zs->zs_refs, NULL) == 0) diff --git a/module/zfs/metaslab.c b/module/zfs/metaslab.c index 94b131fcd..176247d63 100644 --- a/module/zfs/metaslab.c +++ b/module/zfs/metaslab.c @@ -5650,8 +5650,7 @@ metaslab_class_throttle_reserve(metaslab_class_t *mc, int slots, int allocator, * We reserve the slots individually so that we can unreserve * them individually when an I/O completes. */ - for (int d = 0; d < slots; d++) - zfs_refcount_add(&mca->mca_alloc_slots, zio); + zfs_refcount_add_few(&mca->mca_alloc_slots, slots, zio); zio->io_flags |= ZIO_FLAG_IO_ALLOCATING; return (B_TRUE); } @@ -5665,8 +5664,7 @@ metaslab_class_throttle_unreserve(metaslab_class_t *mc, int slots, metaslab_class_allocator_t *mca = &mc->mc_allocator[allocator]; ASSERT(mc->mc_alloc_throttle_enabled); - for (int d = 0; d < slots; d++) - zfs_refcount_remove(&mca->mca_alloc_slots, zio); + zfs_refcount_remove_few(&mca->mca_alloc_slots, slots, zio); } static int diff --git a/module/zfs/refcount.c b/module/zfs/refcount.c index 62ec03e10..c9a504f67 100644 --- a/module/zfs/refcount.c +++ b/module/zfs/refcount.c @@ -151,6 +151,15 @@ zfs_refcount_add(zfs_refcount_t *rc, const void *holder) return (zfs_refcount_add_many(rc, 1, holder)); } +void +zfs_refcount_add_few(zfs_refcount_t *rc, uint64_t number, const void *holder) +{ + if (!rc->rc_tracked) + (void) zfs_refcount_add_many(rc, number, holder); + else for (; number > 0; number--) + (void) zfs_refcount_add(rc, holder); +} + int64_t zfs_refcount_remove_many(zfs_refcount_t *rc, uint64_t number, const void *holder) @@ -205,6 +214,15 @@ zfs_refcount_remove(zfs_refcount_t *rc, const void *holder) } void +zfs_refcount_remove_few(zfs_refcount_t *rc, uint64_t number, const void *holder) +{ + if (!rc->rc_tracked) + (void) zfs_refcount_remove_many(rc, number, holder); + else for (; number > 0; number--) + (void) zfs_refcount_remove(rc, holder); +} + +void zfs_refcount_transfer(zfs_refcount_t *dst, zfs_refcount_t *src) { int64_t count, removed_count; |