---

yaml --- r: 245652 b: refs/heads/master c: d8d9766 h: refs/heads/master v: v3
git-mirror · Apr 18, 2011 · 4623845 · 4623845
1 parent b3c1bee
commit 4623845
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dc326fca2b640fc41aed7c015d0f456935a66255
+refs/heads/master: d8d9766c8c29f71c37bc4b74cc9fcf6a192c9bfd
diff --git a/trunk/arch/x86/kernel/alternative.c b/trunk/arch/x86/kernel/alternative.c
@@ -199,7 +199,19 @@ void __init arch_init_ideal_nops(void)
 {
 	switch (boot_cpu_data.x86_vendor) {
 	case X86_VENDOR_INTEL:
-		if (boot_cpu_has(X86_FEATURE_NOPL)) {
+		/*
+		 * Due to a decoder implementation quirk, some
+		 * specific Intel CPUs actually perform better with
+		 * the "k8_nops" than with the SDM-recommended NOPs.
+		 */
+		if (boot_cpu_data.x86 == 6 &&
+		    boot_cpu_data.x86_model >= 0x0f &&
+		    boot_cpu_data.x86_model != 0x1c &&
+		    boot_cpu_data.x86_model != 0x26 &&
+		    boot_cpu_data.x86_model != 0x27 &&
+		    boot_cpu_data.x86_model < 0x30) {
+			ideal_nops = k8_nops;
+		} else if (boot_cpu_has(X86_FEATURE_NOPL)) {
 			   ideal_nops = p6_nops;
 		} else {
 #ifdef CONFIG_X86_64