]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/commitdiff
x86/tsc: Feed refined TSC calibration into sched_clock()
authorPeter Zijlstra <peterz@infradead.org>
Fri, 21 Apr 2017 09:32:46 +0000 (11:32 +0200)
committerIngo Molnar <mingo@kernel.org>
Mon, 15 May 2017 08:15:16 +0000 (10:15 +0200)
For the (older) CPUs that still need the refined TSC calibration, also
update the sched_clock() rate.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/tsc.c

index dda964c6387d7c99f1087891097554e2f9883c53..66015195bd18c65e147084840ba8ea7d898c9be9 100644 (file)
@@ -1161,6 +1161,7 @@ static void tsc_refine_calibration_work(struct work_struct *work)
        static int hpet;
        u64 tsc_stop, ref_stop, delta;
        unsigned long freq;
+       int cpu;
 
        /* Don't bother refining TSC on unstable systems */
        if (check_tsc_unstable())
@@ -1211,6 +1212,10 @@ static void tsc_refine_calibration_work(struct work_struct *work)
        /* Inform the TSC deadline clockevent devices about the recalibration */
        lapic_update_tsc_freq();
 
+       /* Update the sched_clock() rate to match the clocksource one */
+       for_each_possible_cpu(cpu)
+               __set_cyc2ns_scale(tsc_khz, cpu, tsc_stop);
+
 out:
        if (boot_cpu_has(X86_FEATURE_ART))
                art_related_clocksource = &clocksource_tsc;