Re: [PATCH v1 2/2] virtio-mem: prepare fake page onlining code for granularity smaller than MAX_ORDER - 1

From: David Hildenbrand
Date: Thu Dec 09 2021 - 06:53:09 EST


Hi Eric,

thanks for the review!

>> if (PageDirty(page)) {
>> - virtio_mem_clear_fake_offline(pfn + i, max_nr_pages,
>> - false);
>> - generic_online_page(page, MAX_ORDER - 1);
>> + virtio_mem_clear_fake_offline(pfn + i, 1 << order, false);
>> + generic_online_page(page, order);
>> } else {
>> - virtio_mem_clear_fake_offline(pfn + i, max_nr_pages,
>> - true);
>> - free_contig_range(pfn + i, max_nr_pages);
>> - adjust_managed_page_count(page, max_nr_pages);
>> + virtio_mem_clear_fake_offline(pfn + i, 1 << order, true);
>> + free_contig_range(pfn + i, 1 << order);
>> + adjust_managed_page_count(page, 1 << order);
> In the loop, pfn + i, 1 << order are repeatedly calculated. 1 << order
> is a step size, pfn + i  is each step position.
> Better to figure the numer once each iter?

The compiler better be smart enough to calculate such constants once :)

>
> LGTL.
> LGTM.
> Reviewed-by: Eric Ren <renzhengeek@xxxxxxxxx>

Thanks!


--
Thanks,

David / dhildenb