On 11/10/19 7:21 PM, Ira Weiny wrote:
> On Fri, Nov 08, 2019 at 06:04:34PM -0800, John Hubbard wrote:
>> And get rid of the mmap_sem calls, as part of that. Note
>> that get_user_pages_fast() will, if necessary, fall back to
>> __gup_longterm_unlocked(), which takes the mmap_sem as needed.
>>
>> Cc: Jason Gunthorpe <jgg@xxxxxxxx>
>> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
>
Thanks for the review, Ira! This will show up shortly, in the v3
series of "mm/gup: track dma-pinned pages: FOLL_PIN, FOLL_LONGTERM".
thanks,
--
John Hubbard
NVIDIA
>> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
>> ---
>> drivers/infiniband/core/umem.c | 17 ++++++-----------
>> 1 file changed, 6 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
>> index 24244a2f68cc..3d664a2539eb 100644
>> --- a/drivers/infiniband/core/umem.c
>> +++ b/drivers/infiniband/core/umem.c
>> @@ -271,16 +271,13 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
>> sg = umem->sg_head.sgl;
>>
>> while (npages) {
>> - down_read(&mm->mmap_sem);
>> - ret = get_user_pages(cur_base,
>> - min_t(unsigned long, npages,
>> - PAGE_SIZE / sizeof (struct page *)),
>> - gup_flags | FOLL_LONGTERM,
>> - page_list, NULL);
>> - if (ret < 0) {
>> - up_read(&mm->mmap_sem);
>> + ret = get_user_pages_fast(cur_base,
>> + min_t(unsigned long, npages,
>> + PAGE_SIZE /
>> + sizeof(struct page *)),
>> + gup_flags | FOLL_LONGTERM, page_list);
>> + if (ret < 0)
>> goto umem_release;
>> - }
>>
>> cur_base += ret * PAGE_SIZE;
>> npages -= ret;
>> @@ -288,8 +285,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
>> sg = ib_umem_add_sg_table(sg, page_list, ret,
>> dma_get_max_seg_size(context->device->dma_device),
>> &umem->sg_nents);
>> -
>> - up_read(&mm->mmap_sem);
>> }
>>
>> sg_mark_end(sg);
>> --
>> 2.24.0
>>
>
