From 3fa8aa8e45e52358076eafe4a5f32584caad74b0 Mon Sep 17 00:00:00 2001 From: kib Date: Thu, 23 Jun 2016 08:27:38 +0000 Subject: [PATCH] Add a comment noting locking regime for vm_page_xunbusy(). Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (gjb) --- sys/vm/vm_page.h | 1 + 1 file changed, 1 insertion(+) diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h index 0f0b330e04f5..c915598e6573 100644 --- a/sys/vm/vm_page.h +++ b/sys/vm/vm_page.h @@ -552,6 +552,7 @@ void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line); (m)); \ } while (0) +/* Note: page m's lock must not be owned by the caller. */ #define vm_page_xunbusy(m) do { \ if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ VPB_SINGLE_EXCLUSIVER, VPB_UNBUSIED)) \