Hi John,
On Fri, Jan 24, 2020 at 06:11:14PM -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_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 | 70 ++++++++++++++++++++-- tools/testing/selftests/vm/gup_benchmark.c | 15 ++++- 2 files changed, 79 insertions(+), 6 deletions(-)
diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 8dba38e79a9f..3d5fb765e4e6 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 +21,47 @@ struct gup_benchmark { __u64 expansion[10]; /* For future use */ }; +static void put_back_pages(int cmd, struct page **pages, unsigned long nr_pages)
We received a Clang build report on this patch because the use of PIN_FAST_BENCHMARK and PIN_BENCHMARK in the switch statement below will overflow int; this should be unsigned int to match the cmd parameter in the ioctls.
The report can be read here if you care for it:
https://groups.google.com/d/msg/clang-built-linux/gyGayC_dnis/D1celSStEgAJ
Cheers, Nathan
+{
- int i;
- switch (cmd) {
- case GUP_FAST_BENCHMARK:
- case GUP_LONGTERM_BENCHMARK:
- case GUP_BENCHMARK:
for (i = 0; i < nr_pages; i++)put_page(pages[i]);break;- case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK:
unpin_user_pages(pages, nr_pages);break;- }
+}
+static void verify_dma_pinned(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++) {page = pages[i];if (WARN(!page_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) { @@ -66,6 +109,14 @@ static int __gup_benchmark_ioctl(unsigned int cmd, nr = get_user_pages(addr, nr, gup->flags, pages + i, NULL); break;
case PIN_FAST_BENCHMARK:nr = pin_user_pages_fast(addr, nr, gup->flags,pages + i);break;case PIN_BENCHMARK:nr = pin_user_pages(addr, nr, gup->flags, pages + i,NULL);break;@@ -78,15 +129,22 @@ static int __gup_benchmark_ioctl(unsigned int cmd, } end_time = ktime_get();
- /* Shifting the meaning of nr_pages: now it is actual number pinned: */
- nr_pages = i;
- gup->get_delta_usec = ktime_us_delta(end_time, start_time); gup->size = addr - gup->addr;
- /*
* Take an un-benchmark-timed moment to verify DMA pinned* state: print a warning if any non-dma-pinned pages are found:*/- verify_dma_pinned(cmd, pages, nr_pages);
- start_time = ktime_get();
- for (i = 0; i < nr_pages; i++) {
if (!pages[i])break;put_page(pages[i]);- }
- put_back_pages(cmd, pages, nr_pages);
- end_time = ktime_get(); gup->put_delta_usec = ktime_us_delta(end_time, start_time);
@@ -105,6 +163,8 @@ static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, case GUP_FAST_BENCHMARK: case GUP_LONGTERM_BENCHMARK: case GUP_BENCHMARK:
- case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK: break; default: return -EINVAL;
diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c index 389327e9b30a..43b4dfe161a2 100644 --- a/tools/testing/selftests/vm/gup_benchmark.c +++ b/tools/testing/selftests/vm/gup_benchmark.c @@ -18,6 +18,10 @@ #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) +/* Similar to above, but use FOLL_PIN instead of FOLL_GET. */ +#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark) +#define PIN_BENCHMARK _IOWR('g', 5, struct gup_benchmark)
/* Just the flags we need, copied from mm.h: */ #define FOLL_WRITE 0x01 /* check pte is writable */ @@ -40,8 +44,14 @@ int main(int argc, char **argv) char *file = "/dev/zero"; char *p;
- while ((opt = getopt(argc, argv, "m:r:n:f:tTLUwSH")) != -1) {
- while ((opt = getopt(argc, argv, "m:r:n:f:abtTLUuwSH")) != -1) { switch (opt) {
case 'a':cmd = PIN_FAST_BENCHMARK;break;case 'b':cmd = PIN_BENCHMARK;break;@@ -63,6 +73,9 @@ int main(int argc, char **argv) case 'U': cmd = GUP_BENCHMARK; break;
case 'u':cmd = GUP_FAST_BENCHMARK;break;-- 2.25.0