Hi Mirela,
On 15/05/18 12:44, Mirela Simonovic wrote:
The memory allocated in setup_cpu_sibling_map() when a CPU is hotplugged
has to be freed when the CPU is hot-unplugged. This is done in
remove_cpu_sibling_map() and called when the CPU dies. The call to
remove_cpu_sibling_map() is made from a notifier callback when
CPU_DEAD event is received.
Signed-off-by: Mirela Simonovic <mirela.simono...@aggios.com>
Acked-by: Julien Grall <julien.gr...@arm.com>
Cheers,
---
CC: Stefano Stabellini <sstabell...@kernel.org>
CC: Julien Grall <julien.gr...@arm.com>
---
Changes in v3:
-Use notifier to trigger remove_cpu_sibling_map() when the CPU dies.
Changes in v4:
-Initialize cpu_smpboot notifier at presmp_init rather than init phase
to cover the case where a secondary CPU dies beforehand the initcall
-Added newline before the return in cpu_smpboot_notifier_init()
-Fix indentation in cpu_smpboot_callback() definition
---
xen/arch/arm/smpboot.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index ad1f6b751b..cf3a4ce659 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -89,6 +89,12 @@ static void setup_cpu_sibling_map(int cpu)
cpumask_set_cpu(cpu, per_cpu(cpu_core_mask, cpu));
}
+static void remove_cpu_sibling_map(int cpu)
+{
+ free_cpumask_var(per_cpu(cpu_sibling_mask, cpu));
+ free_cpumask_var(per_cpu(cpu_core_mask, cpu));
+}
+
void __init
smp_clear_cpu_maps (void)
{
@@ -499,6 +505,36 @@ void __cpu_die(unsigned int cpu)
smp_mb();
}
+static int cpu_smpboot_callback(struct notifier_block *nfb,
+ unsigned long action,
+ void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+
+ switch ( action )
+ {
+ case CPU_DEAD:
+ remove_cpu_sibling_map(cpu);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block cpu_smpboot_nfb = {
+ .notifier_call = cpu_smpboot_callback,
+};
+
+static int __init cpu_smpboot_notifier_init(void)
+{
+ register_cpu_notifier(&cpu_smpboot_nfb);
+
+ return 0;
+}
+presmp_initcall(cpu_smpboot_notifier_init);
+
/*
* Local variables:
* mode: C
--
Julien Grall
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel