Hi Mirela, On 27/04/18 18:12, 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> --- 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. --- xen/arch/arm/smpboot.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c index ad1f6b751b..b833e3a754 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 +505,34 @@ 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; +} +__initcall(cpu_smpboot_notifier_init);
I think this notifiers should go in preinit smp to cover the case where a secondary CPU dies beforehand the initcall.
Cheers, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
