Re: [PATCH 1/3] mm/zsmalloc: avoid unregister a NOT-registered zsmalloc zpool driver

From: Minchan Kim
Date: Thu Nov 13 2014 - 18:29:03 EST


Hello Sergey,

On Fri, Nov 14, 2014 at 07:31:27AM +0900, Sergey Senozhatsky wrote:
> On (11/14/14 00:30), Sergey Senozhatsky wrote:
> > Factor out zsmalloc cpu notifier unregistration code and call
> > it from both zs_exit() and zs_init() error path.
>
> I should had have a good sleep before posting this.
> shame on me!
>
> v3
>
> Signed-ogg-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>

Looks good to me. a nitpick.
Could you factor out cpu register part as well as cpu unregister, too?
Then, please resend it with formal description and includes reported-by.

Thanks.

>
> ---
>
> mm/zsmalloc.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index b3b57ef..cd4efa1 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -881,14 +881,10 @@ static struct notifier_block zs_cpu_nb = {
> .notifier_call = zs_cpu_notifier
> };
>
> -static void zs_exit(void)
> +static void zs_unregister_cpu_notifier(void)
> {
> int cpu;
>
> -#ifdef CONFIG_ZPOOL
> - zpool_unregister_driver(&zs_zpool_driver);
> -#endif
> -
> cpu_notifier_register_begin();
>
> for_each_online_cpu(cpu)
> @@ -898,6 +894,14 @@ static void zs_exit(void)
> cpu_notifier_register_done();
> }
>
> +static void zs_exit(void)
> +{
> +#ifdef CONFIG_ZPOOL
> + zpool_unregister_driver(&zs_zpool_driver);
> +#endif
> + zs_unregister_cpu_notifier();
> +}
> +
> static int zs_init(void)
> {
> int cpu, ret;
> @@ -921,7 +925,7 @@ static int zs_init(void)
>
> return 0;
> fail:
> - zs_exit();
> + zs_unregister_cpu_notifier();
> return notifier_to_errno(ret);
> }
>
>
> --
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--
Kind regards,
Minchan Kim
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