From 16f8e842cfad20a6cca1b6e4ad285b40c419e359 Mon Sep 17 00:00:00 2001 From: Alexander Motin Date: Fri, 1 Mar 2024 12:13:09 -0500 Subject: [PATCH] BRT: Skip getting length in brt_entry_lookup() Unlike DDT, where ZAP values may have different lengths due to compression, all BRT entries are identical 8-byte counters. It does not make sense to first fetch the length only to assert it. zap_lookup_uint64() is specifically designed to work with counters of different size and should return error if something odd found. Calling it straight allows to save some measurable CPU time. Signed-off-by: Alexander Motin Sponsored by: iXsystems, Inc. --- module/zfs/brt.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) diff --git a/module/zfs/brt.c b/module/zfs/brt.c index 225ddaca1e54..7921dcbdbd39 100644 --- a/module/zfs/brt.c +++ b/module/zfs/brt.c @@ -901,7 +901,6 @@ static int brt_entry_lookup(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre) { uint64_t mos_entries; - uint64_t one, physsize; int error; ASSERT(RW_LOCK_HELD(&brt->brt_lock)); @@ -919,21 +918,8 @@ brt_entry_lookup(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre) brt_unlock(brt); - error = zap_length_uint64(brt->brt_mos, mos_entries, &bre->bre_offset, - BRT_KEY_WORDS, &one, &physsize); - if (error == 0) { - ASSERT3U(one, ==, 1); - ASSERT3U(physsize, ==, sizeof (bre->bre_refcount)); - - error = zap_lookup_uint64(brt->brt_mos, mos_entries, - &bre->bre_offset, BRT_KEY_WORDS, 1, - sizeof (bre->bre_refcount), &bre->bre_refcount); - BRT_DEBUG("ZAP lookup: object=%llu vdev=%llu offset=%llu " - "count=%llu error=%d", (u_longlong_t)mos_entries, - (u_longlong_t)brtvd->bv_vdevid, - (u_longlong_t)bre->bre_offset, - error == 0 ? (u_longlong_t)bre->bre_refcount : 0, error); - } + error = zap_lookup_uint64(brt->brt_mos, mos_entries, &bre->bre_offset, + BRT_KEY_WORDS, 1, sizeof (bre->bre_refcount), &bre->bre_refcount); brt_wlock(brt);