[Xen-devel] [PATCH v3 1/4] xen/sched: populate cpupool0 only after all cpus are up

Juergen Gross posted 4 patches 6 years, 5 months ago
There is a newer version of this series
[Xen-devel] [PATCH v3 1/4] xen/sched: populate cpupool0 only after all cpus are up
Posted by Juergen Gross 6 years, 5 months ago
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>
---
V1: new patch
---
 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 f90e496eda..caea5bd8b3 100644
--- a/xen/common/cpupool.c
+++ b/xen/common/cpupool.c
@@ -762,18 +762,28 @@ 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:
-- 
2.16.4


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Re: [Xen-devel] [PATCH v3 1/4] xen/sched: populate cpupool0 only after all cpus are up
Posted by Dario Faggioli 6 years, 4 months ago
On Mon, 2019-09-09 at 11:33 +0200, Juergen Gross wrote:
> 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>

Regards
-- 
Dario Faggioli, Ph.D
http://about.me/dario.faggioli
Virtualization Software Engineer
SUSE Labs, SUSE https://www.suse.com/
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