Re: [PATCH v5 07/24] IB/umem: use get_user_pages_fast() to pin DMA pages
From: Jan Kara <jack@suse.cz>
Date: 2019-11-18 12:02:22
Also in:
bpf, dri-devel, kvm, linux-block, linux-doc, linux-fsdevel, linux-kselftest, linux-media, linux-mm, linux-rdma, lkml, netdev
On Thu 14-11-19 21:53:23, 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. Reviewed-by: Jason Gunthorpe <redacted> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza
quoted hunk ↗ jump to hunk
--- 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
-- Jan Kara [off-list ref] SUSE Labs, CR