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 <jgg@xxxxxxxxxxxx> > Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > --- > 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 <jack@xxxxxxxx> SUSE Labs, CR