patch-0007-sched-populate-cpupool0-only-after-all-cpus-are-up.patch

From b3541dd6cdb0ef9f31b8860e59bf0ee524a2c6e6 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@suse.com>
Date: Tue, 17 Sep 2019 16:09:50 +0200
Subject: [PATCH 7/9] sched: populate cpupool0 only after all cpus are up

Simplify cpupool initialization by populating cpupool0 with cpus only
after all cpus are up. This avoids having to call the cpu notifier
directly for cpu 0.

With that in place there is no need to create cpupool0 earlier, so
do that just before assigning the cpus. Initialize free cpus with all
online cpus at that time in order to be able to add the cpu notifier
late, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
(cherry picked from commit b0000b128adb07f4107c6e324d32ab025a73a6c8)
---
 xen/common/cpupool.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/xen/common/cpupool.c b/xen/common/cpupool.c
index cae19fda6e11..7ab13d25ab0e 100644
--- a/xen/common/cpupool.c
+++ b/xen/common/cpupool.c
@@ -768,18 +768,28 @@ static struct notifier_block cpu_nfb = {
     .notifier_call = cpu_callback
 };
 
-static int __init cpupool_presmp_init(void)
+static int __init cpupool_init(void)
 {
+    unsigned int cpu;
     int err;
-    void *cpu = (void *)(long)smp_processor_id();
+
     cpupool0 = cpupool_create(0, 0, &err);
     BUG_ON(cpupool0 == NULL);
     cpupool_put(cpupool0);
-    cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
     register_cpu_notifier(&cpu_nfb);
+
+    spin_lock(&cpupool_lock);
+
+    cpumask_copy(&cpupool_free_cpus, &cpu_online_map);
+
+    for_each_cpu ( cpu, &cpupool_free_cpus )
+        cpupool_assign_cpu_locked(cpupool0, cpu);
+
+    spin_unlock(&cpupool_lock);
+
     return 0;
 }
-presmp_initcall(cpupool_presmp_init);
+__initcall(cpupool_init);
 
 /*
  * Local variables:
-- 
2.26.2