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From: Peter Zijlstra <peterz@infradead.org>
To: tglx@linutronix.de, mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, ville.syrjala@linux.intel.com,
	daniel.lezcano@linaro.org, rafael.j.wysocki@intel.com,
	marta.lofstedt@intel.com, martin.peres@linux.intel.com,
	pasha.tatashin@oracle.com, peterz@infradead.org,
	daniel.vetter@ffwll.ch
Subject: [PATCH 2/9] x86,tsc: Feed refined TSC calibration into sched_clock
Date: Fri, 21 Apr 2017 16:57:58 +0200	[thread overview]
Message-ID: <20170421150733.958440647@infradead.org> (raw)
In-Reply-To: <20170421145756.305735607@infradead.org>

[-- Attachment #1: peterz-sched-clock-rubarb-2.patch --]
[-- Type: text/plain, Size: 915 bytes --]

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>
---
 arch/x86/kernel/tsc.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1267,6 +1267,7 @@ static void tsc_refine_calibration_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())
@@ -1317,6 +1318,10 @@ static void tsc_refine_calibration_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);
+
 out:
 	if (boot_cpu_has(X86_FEATURE_ART))
 		art_related_clocksource = &clocksource_tsc;

  parent reply	other threads:[~2017-04-21 17:10 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-21 14:57 [PATCH 0/9] sched_clock fixes Peter Zijlstra
2017-04-21 14:57 ` [PATCH 1/9] x86/tsc: Provide tsc=unstable boot parameter Peter Zijlstra
2017-04-21 14:57 ` Peter Zijlstra [this message]
2017-04-21 14:57 ` [PATCH 3/9] sched/clock: Initialize all per-cpu state before switching (back) to unstable Peter Zijlstra
2017-04-21 14:58 ` [PATCH 4/9] x86/tsc,sched/clock,clocksource: Use clocksource watchdog to provide stable sync points Peter Zijlstra
2017-04-21 14:58 ` [PATCH 5/9] sched/clock: Remove unused argument to sched_clock_idle_wakeup_event() Peter Zijlstra
2017-04-21 14:58 ` [PATCH 6/9] sched/clock: Remove watchdog touching Peter Zijlstra
2017-04-21 15:28   ` Peter Zijlstra
2017-04-21 14:58 ` [PATCH 8/9] sched/clock: Use late_initcall() instead of sched_init_smp() Peter Zijlstra
2017-04-21 14:58 ` [PATCH 9/9] sched/clock: Print a warning recommending tsc=unstable Peter Zijlstra
2017-04-25  9:31 ` [PATCH 0/9] sched_clock fixes Lofstedt, Marta
2017-04-25 13:44   ` Peter Zijlstra
2017-04-26  6:41     ` Lofstedt, Marta

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