-stable review patch. If anyone has any objections, please let us know.
---------------------
From: Thomas Gleixner <[email protected]>
upstream commit: 74dc51a3de06aa516e3b9fdc4017b2aeb38bf44b
When the TSC calibration fails then TSC is still used in
sched_clock(). Disable it completely in that case.
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Chris Wright <[email protected]>
---
arch/x86/kernel/tsc_32.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -401,6 +401,11 @@ void __init tsc_init(void)
if (!cpu_khz) {
mark_tsc_unstable("could not calculate TSC khz");
+ /*
+ * We need to disable the TSC completely in this case
+ * to prevent sched_clock() from using it.
+ */
+ tsc_disabled = 1;
return;
}
--