Re: [PATCH 1/1] infiniband/mm: convert put_page() to put_user_page*()

John Hubbard
2019-05-23T17:57:59Z

On 5/23/19 8:31 AM, Jerome Glisse wrote:
[...]
>
> Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
>

Thanks for the review!

> Between i have a wishlist see below
[...]
>> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
>> index e7ea819fcb11..673f0d240b3e 100644
>> --- a/drivers/infiniband/core/umem.c
>> +++ b/drivers/infiniband/core/umem.c
>> @@ -54,9 +54,10 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
>>
>> for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) {
>> page = sg_page_iter_page(&sg_iter);
>> - if (!PageDirty(page) && umem->writable && dirty)
>> - set_page_dirty_lock(page);
>> - put_page(page);
>> + if (umem->writable && dirty)
>> + put_user_pages_dirty_lock(&page, 1);
>> + else
>> + put_user_page(page);
>
> Can we get a put_user_page_dirty(struct page 8*pages, bool dirty, npages) ?
>
> It is a common pattern that we might have to conditionaly dirty the pages
> and i feel it would look cleaner if we could move the branch within the
> put_user_page*() function.
>

This sounds reasonable to me, do others have a preference on this? Last time
we discussed it, I recall there was interest in trying to handle the sg lists,
which was where a lot of focus was. I'm not sure if there was a preference one
way or the other, on adding more of these helpers.

thanks,
--
John Hubbard
NVIDIA