From e68465ecbf7371efdab5a7d91838e33f4e5e177b Mon Sep 17 00:00:00 2001 From: Mark Johnston Date: Fri, 17 Sep 2021 12:13:47 -0400 Subject: [PATCH] uma: Show the count of free slabs in each per-domain keg's sysctl tree This is useful for measuring the number of pages that could be freed from a NOFREE zone under memory pressure. Sponsored by: The FreeBSD Foundation (cherry picked from commit d6e77cda9be1509ea170142cca3ff0d3b9f12e35) --- sys/vm/uma_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c index 410d5bb6772..5dfcd0c860e 100644 --- a/sys/vm/uma_core.c +++ b/sys/vm/uma_core.c @@ -2526,7 +2526,10 @@ zone_alloc_sysctl(uma_zone_t zone, void *unused) "Total pages currently allocated from VM"); SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO, "free_items", CTLFLAG_RD, &dom->ud_free_items, 0, - "items free in the slab layer"); + "Items free in the slab layer"); + SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO, + "free_slabs", CTLFLAG_RD, &dom->ud_free_slabs, 0, + "Unused slabs"); } } else SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,