The branch main has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=7585c5db25b700d19baebd7afd7a1b2e03c29cda
commit 7585c5db25b700d19baebd7afd7a1b2e03c29cda
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2021-11-01 13:27:52 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2021-11-01 13:51:43 +0000
uma: Fix handling of reserves in zone_import()
Kegs with no items reserved have uk_reserve = 0. So the check
keg->uk_reserve >= dom->ud_free_items will be true once all slabs are
depleted. Then, rather than go and allocate a fresh slab, we return to
the cache layer.
The intent was to do this only when the keg actually has a reserve, so
modify the check to verify this first. Another approach would be to
make uk_reserve signed and set it to -1 until uma_zone_reserve() is
called, but this requires a few casts elsewhere.
Fixes: 1b2dcc8c54a8 ("uma: Avoid depleting keg reserves when filling a
bucket")
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32516
---
sys/vm/uma_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index de9605a28bb6..7b83d81a423d 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -4038,7 +4038,8 @@ zone_import(void *arg, void **bucket, int max, int
domain, int flags)
dom = &keg->uk_domain[slab->us_domain];
do {
bucket[i++] = slab_alloc_item(keg, slab);
- if (dom->ud_free_items <= keg->uk_reserve) {
+ if (keg->uk_reserve > 0 &&
+ dom->ud_free_items <= keg->uk_reserve) {
/*
* Avoid depleting the reserve after a
* successful item allocation, even if
