From 460d8c960ae542f4331957bb95ba5c56f74df51e Mon Sep 17 00:00:00 2001 From: Taylor R Campbell Date: Thu, 31 Mar 2022 01:24:14 +0000 Subject: [PATCH 17/49] alpha: Omit needless membar in pmap_reference. If the pmap is published enough for us to obtain a reference to it then there's no membar needed. If it's not then something else is wrong and we can't use pmap_reference here anyway. Membars are needed only on the destruction side to make sure all use, by any thread, happens-before all freeing in the last user thread. --- sys/arch/alpha/alpha/pmap.c | 1 - 1 file changed, 1 deletion(-) diff --git a/sys/arch/alpha/alpha/pmap.c b/sys/arch/alpha/alpha/pmap.c index 181a74a7add9..f56a83053607 100644 --- a/sys/arch/alpha/alpha/pmap.c +++ b/sys/arch/alpha/alpha/pmap.c @@ -1706,7 +1706,6 @@ pmap_reference(pmap_t pmap) newcount = atomic_inc_uint_nv(&pmap->pm_count); KASSERT(newcount != 0); - PMAP_MP(membar_enter()); } /*