From a312877651e18175726e33e4530307880d249aa5 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 11 Feb 2015 17:28:14 -0600 Subject: [PATCH 08/22] 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/smpboot.c | 2 +- arch/x86/kernel/tsc.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 36171bcd..7f4e9cdf 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -731,7 +731,7 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) pr_debug("Waiting for send to finish...\n"); send_status = safe_apic_wait_icr_idle(); - udelay(init_udelay); + udelay(100); pr_debug("Deasserting INIT\n"); diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 6e57edf3..94ab049f 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1390,6 +1390,9 @@ unsigned long calibrate_delay_is_known(void) if (!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; -- 2.11.0