On 11/4/19 9:44 AM, Jerome Glisse wrote: > On Sun, Nov 03, 2019 at 01:18:04PM -0800, John Hubbard wrote: >> Convert drm/via to use the new pin_user_pages_fast() call, which sets >> FOLL_PIN. Setting FOLL_PIN is now required for code that requires >> tracking of pinned pages, and therefore for any code that calls >> put_user_page(). >> >> Reviewed-by: Ira Weiny <ira.we...@intel.com> >> Signed-off-by: John Hubbard <jhubb...@nvidia.com> > > Please be more explicit that via_dmablit.c is already using put_user_page() > as i am expecting that any conversion to pin_user_pages*() must be pair with > a put_user_page(). I find above commit message bit unclear from that POV. >
OK. This one, and the fs/io_uring (patch 9) and net/xdp (patch 10) were all cases that had put_user_page() pre-existing. I will add something like the following to each commit description, for v3: In partial anticipation of this work, the drm/via driver was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required is to change get_user_pages() to pin_user_pages(). thanks, John Hubbard NVIDIA > Reviewed-by: Jérôme Glisse <jgli...@redhat.com> > > >> --- >> drivers/gpu/drm/via/via_dmablit.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/via/via_dmablit.c >> b/drivers/gpu/drm/via/via_dmablit.c >> index 3db000aacd26..37c5e572993a 100644 >> --- a/drivers/gpu/drm/via/via_dmablit.c >> +++ b/drivers/gpu/drm/via/via_dmablit.c >> @@ -239,7 +239,7 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg, >> drm_via_dmablit_t *xfer) >> vsg->pages = vzalloc(array_size(sizeof(struct page *), vsg->num_pages)); >> if (NULL == vsg->pages) >> return -ENOMEM; >> - ret = get_user_pages_fast((unsigned long)xfer->mem_addr, >> + ret = pin_user_pages_fast((unsigned long)xfer->mem_addr, >> vsg->num_pages, >> vsg->direction == DMA_FROM_DEVICE ? FOLL_WRITE : 0, >> vsg->pages); >> -- >> 2.23.0 >> > >
