From de829448357b4c9121d466af4b1c3cafd2a8dd3e Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 3 Jan 2011 19:59:24 +0100
Subject: [PATCH] --- yaml --- r: 223736 b: refs/heads/master c:
 a0a2b71bb750ffe9b3faa317cb6317f4ad109383 h: refs/heads/master v: v3

---
 [refs]                                 |  2 +-
 trunk/arch/x86/oprofile/op_model_amd.c | 24 ++++++++++++++++--------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index 242da332c9d5..1ae4980859ea 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d425de5436a620de506f9e4119bf8daa1cb93718
+refs/heads/master: a0a2b71bb750ffe9b3faa317cb6317f4ad109383
diff --git a/trunk/arch/x86/oprofile/op_model_amd.c b/trunk/arch/x86/oprofile/op_model_amd.c
index a011bcc0f943..7d90d47655ba 100644
--- a/trunk/arch/x86/oprofile/op_model_amd.c
+++ b/trunk/arch/x86/oprofile/op_model_amd.c
@@ -630,21 +630,29 @@ static int __init_ibs_nmi(void)
 	return 0;
 }
 
-/* initialize the APIC for the IBS interrupts if available */
+/*
+ * check and reserve APIC extended interrupt LVT offset for IBS if
+ * available
+ *
+ * init_ibs() preforms implicitly cpu-local operations, so pin this
+ * thread to its current CPU
+ */
+
 static void init_ibs(void)
 {
-	ibs_caps = get_ibs_caps();
+	preempt_disable();
 
+	ibs_caps = get_ibs_caps();
 	if (!ibs_caps)
-		return;
+		goto out;
 
-	if (__init_ibs_nmi()) {
+	if (__init_ibs_nmi() < 0)
 		ibs_caps = 0;
-		return;
-	}
+	else
+		printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n", ibs_caps);
 
-	printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n",
-	       (unsigned)ibs_caps);
+out:
+	preempt_enable();
 }
 
 static int (*create_arch_files)(struct super_block *sb, struct dentry *root);