Re: [PATCH v2] mm/memory: drop PROCESS_PAGES_NON_PREEMPT_BATCH

["David Hildenbrand (Arm)" <david@kernel.org>]

On 11/9/26 11:28, Garg, Shivank wrote:
> On Mon, 2026-11-09 at 10:12 +0000, Pedro Falcato wrote:
>>>
>>> No functional change intended.
>>>
>>> Suggested-by: David Hildenbrand <david@kernel.org>
>>> Signed-off-by: Shivank Garg <shivankg@amd.com>
>>
>> Reviewed-by: Pedro Falcato <pfalcato@suse.de>
>>
>> with a question below.
>>
>>> ---
>>> This came up in review of the copy_mc_highpages() series [1]. Pedro
>>> pointed out that most architecture run with full or lazy preempt, so mm
>>> does not need to check the preemption model at runtime or batch the copy
>>>
> 
> 
>>> -
>>> -     might_sleep();
>>> +     if (IS_ENABLED(CONFIG_PREEMPTION)) {
>>> +             clear_user_highpages(page, addr, nr_pages);
>>> +             return;
>>> +     }
>>>
>>> -     for (i = 0; i < nr_pages; i += count) {
>>> +     for (i = 0; i < nr_pages; i++) {
>>>               cond_resched();
>>> -
>>> -             count = min(unit, nr_pages - i);
>>> -             clear_user_highpages(page + i, addr + i * PAGE_SIZE, count);
>>> +             clear_user_highpages(page + i, addr + i * PAGE_SIZE, 1);
>>
>> I think we can use clear_user_highpage() here. I don't know if that's
>> necessarily desirable, but it would make this a little simpler.
>>
> 
> Sure, this makes sense. Will do this in next version.

Makes sense. So I'll wait for the v3 :)

-- 
Cheers,

David