Re: [PATCH 07/19] infiniband: set FOLL_PIN, FOLL_LONGTERM via pin_longterm_pages*()

On 10/31/19 4:25 PM, Ira Weiny wrote:

On Wed, Oct 30, 2019 at 03:49:18PM -0700, John Hubbard wrote:

...

Convert infiniband to use the new wrapper calls, and stop explicitly setting FOLL_LONGTERM at the call sites.

The new pin_longterm_*() calls replace get_user_pages*() calls, and set both FOLL_LONGTERM and a new FOLL_PIN flag. The FOLL_PIN flag requires that the caller must return the pages via put_user_page*() calls, but infiniband was already doing that as part of an earlier commit.

NOTE: I'm not 100% convinced that mixing the flags and new calls like this is good. I think we are going to need a lot more documentation on which flags are "user" accessible vs not...

I'm open to suggestion there. I'm too close to it now to see what's missing, though...maybe after you take a peek at Documentation/ let's see if it's still the case...

thanks,

John Hubbard NVIDIA

Reviewed-by: Ira Weiny ira.weiny@intel.com

...

Signed-off-by: John Hubbard jhubbard@nvidia.com

drivers/infiniband/core/umem.c | 5 ++--- drivers/infiniband/core/umem_odp.c | 10 +++++----- drivers/infiniband/hw/hfi1/user_pages.c | 4 ++-- drivers/infiniband/hw/mthca/mthca_memfree.c | 3 +-- drivers/infiniband/hw/qib/qib_user_pages.c | 8 ++++---- drivers/infiniband/hw/qib/qib_user_sdma.c | 2 +- drivers/infiniband/hw/usnic/usnic_uiom.c | 9 ++++----- drivers/infiniband/sw/siw/siw_mem.c | 5 ++--- 8 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 24244a2f68cc..c5a78d3e674b 100644 --- a/drivers/infiniband/core/umem.c +++ 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);
  

  if (ret < 0) { up_read(&mm->mmap_sem); goto umem_release;

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index 163ff7ba92b7..a38b67b83db5 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -534,7 +534,7 @@ static int ib_umem_odp_map_dma_single_page( } else if (umem_odp->page_list[page_index] == page) { umem_odp->dma_list[page_index] |= access_mask; } else {

• pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n",
  

• pr_err("error: got different pages in IB device and from pin_longterm_pages. IB device page: %p, gup page: %p\n",
    umem_odp->page_list[page_index], page);
  

  /* Better remove the mapping now, to prevent any further
  • damage. */

@@ -639,11 +639,11 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, /* * Note: this might result in redundent page getting. We can * avoid this by checking dma_list to be 0 before calling

•  * get_user_pages. However, this make the code much more
  

•  * complex (and doesn't gain us much performance in most use
  

•  * cases).
  

•  * pin_longterm_pages. However, this makes the code much
  

•  * more complex (and doesn't gain us much performance in most
  

•  * use cases).
  

  */

• npages = get_user_pages_remote(owning_process, owning_mm,
  

• npages = pin_longterm_pages_remote(owning_process, owning_mm,
  	user_virt, gup_num_pages,
  	flags, local_page_list, NULL, NULL);
  

  up_read(&owning_mm->mmap_sem);

diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c index 469acb961fbd..9b55b0a73e29 100644 --- a/drivers/infiniband/hw/hfi1/user_pages.c +++ b/drivers/infiniband/hw/hfi1/user_pages.c @@ -104,9 +104,9 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np bool writable, struct page **pages) { int ret;

• unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0);

• unsigned int gup_flags = (writable ? FOLL_WRITE : 0);

• ret = get_user_pages_fast(vaddr, npages, gup_flags, pages);

• ret = pin_longterm_pages_fast(vaddr, npages, gup_flags, pages); if (ret < 0) return ret;

diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c index edccfd6e178f..beec7e4b8a96 100644 --- a/drivers/infiniband/hw/mthca/mthca_memfree.c +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c @@ -472,8 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, goto out; }

• ret = get_user_pages_fast(uaddr & PAGE_MASK, 1,

• 		  FOLL_WRITE | FOLL_LONGTERM, pages);
  

• ret = pin_longterm_pages_fast(uaddr & PAGE_MASK, 1, FOLL_WRITE, pages); if (ret < 0) goto out;

diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index 6bf764e41891..684a14e14d9b 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -108,10 +108,10 @@ int qib_get_user_pages(unsigned long start_page, size_t num_pages, down_read(&current->mm->mmap_sem); for (got = 0; got < num_pages; got += ret) {

• ret = get_user_pages(start_page + got * PAGE_SIZE,
  

• 		     num_pages - got,
  

• 		     FOLL_LONGTERM | FOLL_WRITE | FOLL_FORCE,
  

• 		     p + got, NULL);
  

• ret = pin_longterm_pages(start_page + got * PAGE_SIZE,
  

• 			 num_pages - got,
  

• 			 FOLL_WRITE | FOLL_FORCE,
  

• 			 p + got, NULL);
  

  if (ret < 0) { up_read(&current->mm->mmap_sem); goto bail_release;

diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c index 05190edc2611..fd86a9d19370 100644 --- a/drivers/infiniband/hw/qib/qib_user_sdma.c +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c @@ -670,7 +670,7 @@ static int qib_user_sdma_pin_pages(const struct qib_devdata *dd, else j = npages;

• ret = get_user_pages_fast(addr, j, FOLL_LONGTERM, pages);
  

• ret = pin_longterm_pages_fast(addr, j, 0, pages);
  

  if (ret != j) { i = 0; j = ret;

diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 62e6ffa9ad78..6b90ca1c3771 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -141,11 +141,10 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, ret = 0; while (npages) {

• ret = get_user_pages(cur_base,
  

• 		     min_t(unsigned long, npages,
  

• 		     PAGE_SIZE / sizeof(struct page *)),
  

• 		     gup_flags | FOLL_LONGTERM,
  

• 		     page_list, NULL);
  

• ret = pin_longterm_pages(cur_base,
  

• 			 min_t(unsigned long, npages,
  

• 			     PAGE_SIZE / sizeof(struct page *)),
  

• 			 gup_flags, page_list, NULL);
  

if (ret < 0) goto out; diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index e99983f07663..20e663d7ada8 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -426,9 +426,8 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) while (nents) { struct page **plist = &umem->page_chunk[i].plist[got];

• 	rv = get_user_pages(first_page_va, nents,
  

• 			    foll_flags | FOLL_LONGTERM,
  

• 			    plist, NULL);
  

• 	rv = pin_longterm_pages(first_page_va, nents,
  

• 				foll_flags, plist, NULL);
  if (rv < 0)
  	goto out_sem_up;
  

2.23.0