From d4d6be499fa72ecc099ae84b58a37837442b33a1 Mon Sep 17 00:00:00 2001
From: Joseph Koshy <jkoshy@FreeBSD.org>
Date: Mon, 22 Aug 2005 02:59:51 +0000
Subject: [PATCH] Turn off sampling modes on the AMD64 till the time I can
 track down the reason for the double fault seen when sampling under load.

MFC after:	3 days
---
 sys/dev/hwpmc/hwpmc_amd.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/dev/hwpmc/hwpmc_amd.c b/sys/dev/hwpmc/hwpmc_amd.c
index 6285f7fd75ba..280e80a8195d 100644
--- a/sys/dev/hwpmc/hwpmc_amd.c
+++ b/sys/dev/hwpmc/hwpmc_amd.c
@@ -474,6 +474,11 @@ amd_allocate_pmc(int cpu, int ri, struct pmc *pm,
 		return 0;
 	}
 
+#if	__amd64__
+	if (pd->pd_caps & PMC_CAP_INTERRUPT)
+		return EOPNOTSUPP;	/* XXX avoid a processor double fault */
+#endif
+
 #if	DEBUG
 	KASSERT(pd->pd_class == amd_pmc_class,
 	    ("[amd,%d] Unknown PMC class (%d)", __LINE__, pd->pd_class));