From c75da776c29e060b1f4cacc351ea9a91a07b01ed Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Wed, 5 Mar 2014 01:34:10 +0000 Subject: [PATCH] Disable amd64 TLB Context ID (pcid) by default for now There are a number of reports of userspace application crashes that are "solved" by setting vm.pmap.pcid_enabled=0, including Java and the x11/mate-terminal port (PR ports/184362). I originally planned to disable this only in stable/10 (in r262753), but it has been pointed out that additional crash reports on HEAD are not likely to provide new insight into the problem. The feature can easily be enabled for testing. --- sys/amd64/amd64/pmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 10490df6fbd..b62f968e1ad 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -367,7 +367,7 @@ static int pmap_flags = PMAP_PDE_SUPERPAGE; /* flags for x86 pmaps */ static struct unrhdr pcid_unr; static struct mtx pcid_mtx; -int pmap_pcid_enabled = 1; +int pmap_pcid_enabled = 0; SYSCTL_INT(_vm_pmap, OID_AUTO, pcid_enabled, CTLFLAG_RDTUN, &pmap_pcid_enabled, 0, "Is TLB Context ID enabled ?"); int invpcid_works = 0;