Re: [PATCH] s390x/mm: avoid taking the table lock in gmap_pmd_op_walk()

From: David Hildenbrand
Date: Tue Aug 07 2018 - 04:36:16 EST


On 07.08.2018 09:26, Janosch Frank wrote:
> On 06.08.2018 17:54, David Hildenbrand wrote:
>> Right now we temporarily take the page table lock in gmap_pmd_op_walk()
>> even though we know we won't need it (if we can never have 1mb pages
>> mapped into the gmap).
>>
>> So let's special case this, so
>> gmap_protect_range()/gmap_sync_dirty_log_pmd() will not take the lock in
>> case huge pages are not allowed.
>
> So, let's make this a special case
>
>>
>> gmap_protect_range() is called quite frequently for managing shadow
>> page tables in vSIE environments.
>>
>> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
>
> If you make the patch title more specific:
> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>


"s390/mm: optimize locking without huge pages in gmap_pmd_op_walk()"

Thanks!

--

Thanks,

David / dhildenb