From 283fcb879f66da9659f1983bcf173476bae9292b Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 11 Feb 2015 17:28:14 -0600 Subject: [PATCH 114/126] smpboot: reuse timer calibration NO point recalibrating for known-constant tsc... saves 200ms+ of boot time. Author: Arjan van de Ven Signed-off-by: Miguel Bernal Marin --- arch/x86/kernel/tsc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index ad2b925a808e..6aed4e79f290 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1352,6 +1352,9 @@ unsigned long calibrate_delay_is_known(void) if (tsc_disabled || !constant_tsc || !mask) return 0; + if (cpu != 0) + return cpu_data(0).loops_per_jiffy; + sibling = cpumask_any_but(mask, cpu); if (sibling < nr_cpu_ids) return cpu_data(sibling).loops_per_jiffy; -- 2.15.0