Re: [PATCH] drm/via: use get_user_pages_unlocked()

[Lorenzo Stoakes <lstoakes@gmail.com>]

On 6 January 2017 at 07:09, Lorenzo Stoakes <lstoakes@gmail.com> wrote:
>
> Adding Andrew, as this may be another less active corner of the corner, thanks!

Hi all,

Thought I'd also give this one a gentle nudge now the merge window has
re-opened, Andrew - are you ok to pick this up? I've checked the patch
and it still applies, for convenience the raw patch is available at
https://marc.info/?l=linux-mm&m=147802942832515&q=raw - let me know if
there's anything else I can do on this or if you'd prefer a re-send.

Best, Lorenzo

> On 3 January 2017 at 20:23, Lorenzo Stoakes <lstoakes@gmail.com> wrote:
>> Hi All,
>>
>> Just a gentle ping on this one :)
>>
>> Cheers, Lorenzo
>>
>> On 1 November 2016 at 19:43, Lorenzo Stoakes <lstoakes@gmail.com> wrote:
>>> Moving from get_user_pages() to get_user_pages_unlocked() simplifies the code
>>> and takes advantage of VM_FAULT_RETRY functionality when faulting in pages.
>>>
>>> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
>>> ---
>>>  drivers/gpu/drm/via/via_dmablit.c | 10 +++-------
>>>  1 file changed, 3 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c
>>> index 1a3ad76..98aae98 100644
>>> --- a/drivers/gpu/drm/via/via_dmablit.c
>>> +++ b/drivers/gpu/drm/via/via_dmablit.c
>>> @@ -238,13 +238,9 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg,  drm_via_dmablit_t *xfer)
>>>         vsg->pages = vzalloc(sizeof(struct page *) * vsg->num_pages);
>>>         if (NULL == vsg->pages)
>>>                 return -ENOMEM;
>>> -       down_read(&current->mm->mmap_sem);
>>> -       ret = get_user_pages((unsigned long)xfer->mem_addr,
>>> -                            vsg->num_pages,
>>> -                            (vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 0,
>>> -                            vsg->pages, NULL);
>>> -
>>> -       up_read(&current->mm->mmap_sem);
>>> +       ret = get_user_pages_unlocked((unsigned long)xfer->mem_addr,
>>> +                       vsg->num_pages, vsg->pages,
>>> +                       (vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 0);
>>>         if (ret != vsg->num_pages) {
>>>                 if (ret < 0)
>>>                         return ret;
>>> --
>>> 2.10.2
>>>

-- 
Lorenzo Stoakes
https://ljs.io