From 00da8f80eea6ed968c6604d76c69f38325c8dd66 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 11 Feb 2015 17:28:14 -0600 Subject: [PATCH] smpboot: reuse timer calibration NO point recalibrating for known-constant tsc ... saves 200ms+ of boot time. --- 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 2e076a459a0c0..94bc1166476ed 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1549,6 +1549,9 @@ unsigned long calibrate_delay_is_known(void) if (!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; -- 2.50.1