On Thu, Jun 9, 2016 at 11:43 PM, Lianwei Wang <lianwei.w...@gmail.com> wrote:
> Currently it just print a warning message but did not
> reset cpu_hotplug_disabled when the enable/disable is
> unbalanced. The unbalanced enable/disable will lead
> the cpu hotplug work abnormally.
>
> Do nothing if an unablanced hotplug enable detected.
>
> Signed-off-by: Lianwei Wang <lianwei.w...@gmail.com>
> ---
> kernel/cpu.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/cpu.c b/kernel/cpu.c
> index 3e3f6e49eabb..5e26a3c64934 100644
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -245,6 +245,14 @@ void cpu_hotplug_done(void)
> cpuhp_lock_release();
> }
>
> +static void __cpu_hotplug_enable(void)
> +{
> + if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug
> enable\n"))
> + return;
> +
> + cpu_hotplug_disabled--;
> +}
> +
> /*
> * Wait for currently running CPU hotplug operations to complete (if any) and
> * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock'
> protects
> @@ -263,7 +271,7 @@ EXPORT_SYMBOL_GPL(cpu_hotplug_disable);
> void cpu_hotplug_enable(void)
> {
> cpu_maps_update_begin();
> - WARN_ON(--cpu_hotplug_disabled < 0);
> + __cpu_hotplug_enable();
> cpu_maps_update_done();
> }
> EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
> @@ -1091,7 +1099,7 @@ void enable_nonboot_cpus(void)
>
> /* Allow everyone to use the CPU hotplug again */
> cpu_maps_update_begin();
> - WARN_ON(--cpu_hotplug_disabled < 0);
> + __cpu_hotplug_enable();
> if (cpumask_empty(frozen_cpus))
> goto out;
>
> --
> 1.9.1
>
Hi Thomas Gleixner,
Does this change look good to you?
