On Mon, Nov 04, 2019 at 12:48:13PM -0800, John Hubbard wrote:
> On 11/4/19 12:33 PM, Jason Gunthorpe wrote:
> ...
> >> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> >> index 24244a2f68cc..c5a78d3e674b 100644
> >> +++ b/drivers/infiniband/core/umem.c
> >> @@ -272,11 +272,10 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
> >>
> >> while (npages) {
> >> down_read(&mm->mmap_sem);
> >> - ret = get_user_pages(cur_base,
> >> + ret = pin_longterm_pages(cur_base,
> >> min_t(unsigned long, npages,
> >> PAGE_SIZE / sizeof (struct page *)),
> >> - gup_flags | FOLL_LONGTERM,
> >> - page_list, NULL);
> >> + gup_flags, page_list, NULL);
> >
> > FWIW, this one should be converted to fast as well, I think we finally
> > got rid of all the blockers for that?
> >
>
> I'm not aware of any blockers on the gup.c end, anyway. The only broken thing we
> have there is "gup remote + FOLL_LONGTERM". But we can do "gup fast + LONGTERM".
I mean the use of the mmap_sem here is finally in a way where we can
just delete the mmap_sem and use _fast
ie, AFAIK there is no need for the mmap_sem to be held during
ib_umem_add_sg_table()
This should probably be a standalone patch however
Jason
