lkml.org 
[lkml]   [2009]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
DateFri, 13 Nov 2009 15:51:02 -0800
FromAndrew Morton <>
SubjectRe: [PATCH] Allow memory hotplug and hibernation in the same kernel
On Fri, 13 Nov 2009 11:59:44 +0100
Andi Kleen <andi@firstfloor.org> wrote:

> Allow memory hotplug and hibernation in the same kernel
>
> Memory hotplug and hibernation was excluded in Kconfig. This is obviously
> a problem for distribution kernels who want to support both in the same
> image.
>
> After some discussions with Rafael and others the only problem is
> with parallel memory hotadd or removal while a hibernation operation
> is in process. It was also working for s390 before.
>
> This patch removes the Kconfig level exclusion, and simply
> makes the memory add / remove functions grab the pm_mutex
> to exclude against hibernation.
>
> ...
>
> +extern struct mutex pm_mutex;

Am a bit worried by the new mutex.

> #ifndef CONFIG_HIBERNATION
> static inline void register_nosave_region(unsigned long b, unsigned long e)
> {
> @@ -308,8 +310,23 @@ static inline void register_nosave_regio
> static inline void register_nosave_region_late(unsigned long b, unsigned long e)
> {
> }
> -#endif
>
> -extern struct mutex pm_mutex;
> +static inline void lock_hibernation(void) {}
> +static inline void unlock_hibernation(void) {}
> +
> +#else
> +
> +/* Let some subsystems like memory hotadd exclude hibernation */
> +
> +static inline void lock_hibernation(void)
> +{
> + mutex_lock(&pm_mutex);
> +}
> +
> +static inline void unlock_hibernation(void)
> +{
> + mutex_unlock(&pm_mutex);
> +}
> +#endif

Has this been carefully reviewed and lockdep-tested to ensure that we
didn't introduce any ab/ba nasties?




\
 
 \ /
  Last update: 2009-11-14 00:53    [from the cache]
©2003-2010