Re: [PATCH v3 3/5] bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()

[Andy Shevchenko]

On Tue, Jun 19, 2018 at 1:01 AM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
> On Mon, Jun 18, 2018 at 2:14 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> On Mon, 18 Jun 2018 16:10:01 +0300 Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>>
>> > A lot of code become ugly because of open coding allocations for bitmaps.
>> >
>> > Introduce three helpers to allow users be more clear of intention
>> > and keep their code neat.
>> >
>> > ...
>> >
>> > +unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
>> > +{
>> > +     return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), flags);
>> > +}
>> > +EXPORT_SYMBOL(bitmap_alloc);
>> > +
>> > +unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
>> > +{
>> > +     return bitmap_alloc(nbits, flags | __GFP_ZERO);
>> > +}
>> > +EXPORT_SYMBOL(bitmap_zalloc);
>> > +
>> > +void bitmap_free(const unsigned long *bitmap)
>> > +{
>> > +     kfree(bitmap);
>> > +}
>> > +EXPORT_SYMBOL(bitmap_free);
>> > +
>>
>> I suggest these functions are small and simple enough to justify
>> inlining them.
>>
>
> We can't as we end up including bitmap.h (by the way of cpumask.h)
> form slab.h, so we gen circular dependency. Maybe if we removed memcg
> stuff from slab.h so we do not need to include workqueue.h...

I will look at it. It might be doable.
Though I dunno what MM people would say about this. Anyone's name
comes to your mind to ask?

-- 
With Best Regards,
Andy Shevchenko