| Message ID | 20191109020434.389855-2-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IB/umem: use get_user_pages_fast() to pin DMA pages | expand |
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@ziepe.ca> > Cc: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> > Signed-off-by: John Hubbard <jhubbard@nvidia.com> > --- > 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 >
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@ziepe.ca> >> Cc: Ira Weiny <ira.weiny@intel.com> > > Reviewed-by: Ira Weiny <ira.weiny@intel.com> > 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,
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@ziepe.ca> > Cc: Ira Weiny <ira.weiny@intel.com> > Signed-off-by: John Hubbard <jhubbard@nvidia.com> > --- > drivers/infiniband/core/umem.c | 17 ++++++----------- > 1 file changed, 6 insertions(+), 11 deletions(-) Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> This can go through Andrew's tree if he takes this larger series, otherwise I'll grab it Thanks, Jason
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);
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@ziepe.ca> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- drivers/infiniband/core/umem.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-)