From: Andi Kleen <ak@suse.de>
Date: Wed, 30 Jan 2008 12:33:20 +0000 (+0100)
Subject: x86: don't disable RDTSC in userland for 32bit notsc
X-Git-Tag: v2.6.25-rc1~1143^2~231
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8424950b5e85543a494b5d940bb2f5f9f16f56a9;p=linux-2.6

x86: don't disable RDTSC in userland for 32bit notsc

Modern 32bit userland doesn't even boot when the TSC is disabled
because ld.so tends to contain RDTSCs.  So make notsc only effective for the
kernel, similar to 64bit.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 5f9c8e3a3e..c66991a04a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -654,7 +654,6 @@ void __cpuinit cpu_init(void)
 		printk(KERN_NOTICE "Disabling TSC...\n");
 		/**** FIX-HPA: DOES THIS REALLY BELONG HERE? ****/
 		clear_bit(X86_FEATURE_TSC, boot_cpu_data.x86_capability);
-		set_in_cr4(X86_CR4_TSD);
 	}
 
 	load_idt(&idt_descr);