From: David Woodhouse <dwmw@amazon.co.uk>
Date: Tue, 14 Dec 2021 17:39:15 +0000 (+0000)
Subject: callin debug
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=refs%2Fheads%2Fparallel-debug;p=users%2Fdwmw2%2Flinux.git

callin debug
---

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 4fde609107d84..5f49eba51c414 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -172,7 +172,7 @@ static void init_freq_invariance(bool secondary, bool cppc_ready);
 static void smp_callin(void)
 {
 	int cpuid;
-
+	cycles_t t[6];
 	/*
 	 * If waken up by an INIT in an 82489DX configuration
 	 * cpu_callout_mask guarantees we don't get here before
@@ -181,6 +181,7 @@ static void smp_callin(void)
 	 */
 	cpuid = smp_processor_id();
 
+	t[0] = get_cycles();
 	/*
 	 * the boot CPU has finished the init stage and is spinning
 	 * on callin_map until we finish. We are free to set up this
@@ -188,6 +189,7 @@ static void smp_callin(void)
 	 * boards)
 	 */
 	apic_ap_setup();
+	t[1] = get_cycles();
 
 	/*
 	 * Save our processor parameters and update topology.
@@ -196,8 +198,10 @@ static void smp_callin(void)
 	 * calibrate_delay() and notify_cpu_starting().
 	 */
 	smp_store_cpu_info(cpuid, false);
+	t[2] = get_cycles();
 
 	init_freq_invariance(true, false);
+	t[3] = get_cycles();
 
 	/*
 	 * Get our bogomips.
@@ -208,19 +212,21 @@ static void smp_callin(void)
 	calibrate_delay();
 	cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
 	pr_debug("Stack at about %p\n", &cpuid);
+	t[4] = get_cycles();
 
 	wmb();
-
 	/*
 	 * This runs the AP through all the cpuhp states to its target
 	 * state (CPUHP_ONLINE in the case of serial bringup).
 	 */
 	notify_cpu_starting(cpuid);
-
+	t[5] = get_cycles();
 	/*
 	 * Allow the master to continue.
 	 */
 	cpumask_set_cpu(cpuid, cpu_callin_mask);
+	printk("callin CPU %d started in %lld %lld %lld %lld %lld cycles\n", cpuid,
+	       t[1] - t[0], t[2] - t[1], t[3] - t[2], t[4] - t[3], t[5] - t[4]);
 }
 
 static int cpu0_logical_apicid;