Commit-ID: 5e3c1afd4587e70c201bf7224b51f747c9a3dfa8 Gitweb: http://git.kernel.org/tip/5e3c1afd4587e70c201bf7224b51f747c9a3dfa8 Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Wed, 22 Jan 2014 22:08:14 +0100 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 23 Jan 2014 14:48:36 +0100 sched/x86/tsc: Initialize multiplier to 0 Since we keep the clock value linearly continuous on frequency change, make sure the initial multiplier is 0, such that our initial value is 0. Without this we compute the initial value at whatever the TSC has managed to reach since power-on. Reported-and-Tested-by: Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx> Fixes: 20d1c86a57762 ("sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs") Cc: lenb@xxxxxxxxxx Cc: rjw@xxxxxxxxxxxxx Cc: Eliezer Tamir <eliezer.tamir@xxxxxxxxxxxxxxx> Cc: rui.zhang@xxxxxxxxx Cc: jacob.jun.pan@xxxxxxxxxxxxxxx Cc: Mike Galbraith <bitbucket@xxxxxxxxx> Cc: hpa@xxxxxxxxx Cc: paulmck@xxxxxxxxxxxxxxxxxx Cc: John Stultz <john.stultz@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> Cc: Sasha Levin <sasha.levin@xxxxxxxxxx> Cc: dyoung@xxxxxxxxxx Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20140123094804.GP30183@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/tsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index a3acbac..19e5adb 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -180,7 +180,7 @@ static void cyc2ns_write_end(int cpu, struct cyc2ns_data *data) static void cyc2ns_data_init(struct cyc2ns_data *data) { - data->cyc2ns_mul = 1U << CYC2NS_SCALE_FACTOR; + data->cyc2ns_mul = 0; data->cyc2ns_shift = CYC2NS_SCALE_FACTOR; data->cyc2ns_offset = 0; data->__count = 0; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html