Re: [PATCH v2] mm/memory: drop PROCESS_PAGES_NON_PREEMPT_BATCH
From: David Hildenbrand (Arm)
Date: Mon Nov 09 2026 - 07:18:11 EST
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@xxxxxxxxxx>
>>> Signed-off-by: Shivank Garg <shivankg@xxxxxxx>
>>
>> Reviewed-by: Pedro Falcato <pfalcato@xxxxxxx>
>>
>> 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