On Fri, Jan 31, 2020 at 07:40:28PM -0800, John Hubbard wrote:
Up until now, gup_benchmark supported testing of the following kernel functions:
- get_user_pages(): via the '-U' command line option
- get_user_pages_longterm(): via the '-L' command line option
- get_user_pages_fast(): as the default (no options required)
Add test coverage for the new corresponding pin_*() functions:
- pin_user_pages_fast(): via the '-a' command line option
- pin_user_pages(): via the '-b' command line option
Also, add an option for clarity: '-u' for what is now (still) the default choice: get_user_pages_fast().
Also, for the commands that set FOLL_PIN, verify that the pages really are dma-pinned, via the new is_dma_pinned() routine. Those commands are:
PIN_FAST_BENCHMARK : calls pin_user_pages_fast() PIN_BENCHMARK : calls pin_user_pages()In between the calls to pin_*() and unpin_user_pages(), check each page: if page_maybe_dma_pinned() returns false, then WARN and return.
Do this outside of the benchmark timestamps, so that it doesn't affect reported times.
Reviewed-by: Ira Weiny ira.weiny@intel.com Signed-off-by: John Hubbard jhubbard@nvidia.com
mm/gup_benchmark.c | 71 ++++++++++++++++++++-- tools/testing/selftests/vm/gup_benchmark.c | 15 ++++- 2 files changed, 80 insertions(+), 6 deletions(-)
diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 8dba38e79a9f..447628d0131f 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -8,6 +8,8 @@ #define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) +#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark) +#define PIN_BENCHMARK _IOWR('g', 5, struct gup_benchmark) struct gup_benchmark { __u64 get_delta_usec; @@ -19,6 +21,48 @@ struct gup_benchmark { __u64 expansion[10]; /* For future use */ }; +static void put_back_pages(unsigned int cmd, struct page **pages,
unsigned long nr_pages)+{
- int i;
- switch (cmd) {
- case GUP_FAST_BENCHMARK:
- case GUP_LONGTERM_BENCHMARK:
- case GUP_BENCHMARK:
for (i = 0; i < nr_pages; i++)
'i' is 'int' and 'nr_pages' is 'unsigned long'. There's space for trouble :P
put_page(pages[i]);break;- case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK:
unpin_user_pages(pages, nr_pages);break;- }
+}
+static void verify_dma_pinned(unsigned int cmd, struct page **pages,
unsigned long nr_pages)+{
- int i;
- struct page *page;
- switch (cmd) {
- case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK:
for (i = 0; i < nr_pages; i++) {
Ditto.
page = pages[i];if (WARN(!page_maybe_dma_pinned(page),"pages[%d] is NOT dma-pinned\n", i)) {dump_page(page, "gup_benchmark failure");break;}}break;- }
+}
static int __gup_benchmark_ioctl(unsigned int cmd, struct gup_benchmark *gup) {