From 41c45d37b9ee6d2d06e1d4b72e338f7e562d23dd Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Wed, 1 Apr 2020 21:05:41 -0700 Subject: [PATCH] mm/gup_benchmark: support pin_user_pages() and related calls MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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. Signed-off-by: John Hubbard Signed-off-by: Andrew Morton Reviewed-by: Ira Weiny Acked-by: Kirill A. Shutemov Cc: Jan Kara Cc: Jérôme Glisse Cc: "Matthew Wilcox (Oracle)" Cc: Al Viro Cc: Christoph Hellwig Cc: Dan Williams Cc: Dave Chinner Cc: Jason Gunthorpe Cc: Jonathan Corbet Cc: Michal Hocko Cc: Mike Kravetz Cc: Shuah Khan Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20200211001536.1027652-10-jhubbard@nvidia.com Signed-off-by: Linus Torvalds --- 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 8dba38e..be690fa 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) +{ + unsigned long 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(unsigned int cmd, struct page **pages, + unsigned long nr_pages) +{ + unsigned long 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_maybe_dma_pinned(page), + "pages[%lu] 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 +110,14 @@ 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; default: kvfree(pages); ret = -EINVAL; @@ -78,15 +130,22 @@ 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 +164,8 @@ 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 389327e..43b4dfe 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; case 'm': size = atoi(optarg) * MB; break; @@ -63,6 +73,9 @@ int main(int argc, char **argv) case 'U': cmd = GUP_BENCHMARK; break; + case 'u': + cmd = GUP_FAST_BENCHMARK; + break; case 'w': write = 1; break; -- 2.7.4