---

yaml --- r: 335997 b: refs/heads/master c: 2bbf0a1 h: refs/heads/master i: 335995: 50bb1b0 v: v3
git-mirror · Oct 31, 2012 · c2235cc · c2235cc
1 parent aeb1f6e
commit c2235cc
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 37aeec36220c39f1b2e7118287d951fd9cfdd6b7
+refs/heads/master: 2bbf0a1427c377350f001fbc6260995334739ad7
diff --git a/trunk/arch/x86/kernel/cpu/amd.c b/trunk/arch/x86/kernel/cpu/amd.c
@@ -631,6 +631,20 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 		}
 	}
 
+	/*
+	 * The way access filter has a performance penalty on some workloads.
+	 * Disable it on the affected CPUs.
+	 */
+	if ((c->x86 == 0x15) &&
+	    (c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
+		u64 val;
+
+		if (!rdmsrl_safe(0xc0011021, &val) && !(val & 0x1E)) {
+			val |= 0x1E;
+			wrmsrl_safe(0xc0011021, val);
+		}
+	}
+
 	cpu_detect_cache_sizes(c);
 
 	/* Multi core CPU? */