[Xen-changelog] [xen staging] xen/arm: Free memory allocated for sibling/core maps on CPU hot-unplug

[patchbot@xxxxxxx]

commit 517e58d610443c9e68ae5687b450d515b4f8c6e3
Author:     Mirela Simonovic <mirela.simonovic@xxxxxxxxxx>
AuthorDate: Fri Jun 1 15:17:49 2018 +0200
Commit:     Julien Grall <julien.grall@xxxxxxx>
CommitDate: Tue Jun 5 19:08:05 2018 +0100

    xen/arm: Free memory allocated for sibling/core maps on CPU hot-unplug
    
    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.simonovic@xxxxxxxxxx>
    Acked-by: Julien Grall <julien.grall@xxxxxxx>
---
 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
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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