Re: [PATCH v4] mm: cma: support sysfs

Dmitry Osipenko
2021-03-19T13:52:15Z

19.03.2021 16:47, Greg Kroah-Hartman пишет:
> On Fri, Mar 19, 2021 at 04:45:21PM +0300, Dmitry Osipenko wrote:
>> 19.03.2021 16:42, Greg Kroah-Hartman пишет:
>>> On Fri, Mar 19, 2021 at 04:39:41PM +0300, Dmitry Osipenko wrote:
>>>> 19.03.2021 15:44, Dmitry Osipenko пишет:
>>>> ...
>>>>>> #include <linux/debugfs.h>
>>>>>> +#include <linux/kobject.h>
>>>>>> +
>>>>>> +struct cma_stat {
>>>>>> + spinlock_t lock;
>>>>>> + /* the number of CMA page successful allocations */
>>>>>> + unsigned long nr_pages_succeeded;
>>>>>> + /* the number of CMA page allocation failures */
>>>>>> + unsigned long nr_pages_failed;
>>>>>> + struct kobject kobj;
>>>>>> +};
>>>>>>
>>>>>> struct cma {
>>>>>> unsigned long base_pfn;
>>>>>> @@ -16,6 +26,9 @@ struct cma {
>>>>>> struct debugfs_u32_array dfs_bitmap;
>>>>>> #endif
>>>>>> char name[CMA_MAX_NAME];
>>>>>> +#ifdef CONFIG_CMA_SYSFS
>>>>>> + struct cma_stat *stat;
>>>>>> +#endif
>>>>
>>>> What is the point of allocating stat dynamically?
>>>
>>> Because static kobjects make me cry.
>>>
>>
>> I meant that it's already a part of struct cma, it looks like the stat
>> could be embedded into struct cma and then kobj could be initialized
>> separately.
>
> But that structure is statically allocated, so it can not be. This has
> been discussed in the past threads for when this was reviewed if you are
> curious :)

Indeed, I missed that cma_areas[] is static, thank you.