| Message ID | 20200201034029.4063170-12-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/gup: track FOLL_PIN pages | expand |
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) > {
On 2/3/20 5:58 AM, Kirill A. Shutemov wrote: ... >> @@ -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 > Yes, I've changed it to "unsigned int", thanks. >> + 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. > Fixed here also. >> + page = pages[i]; >> + if (WARN(!page_maybe_dma_pinned(page), >> + "pages[%d] is NOT dma-pinned\n", i)) { ...and changed to "pages[%u]", to match. thanks,
On Mon, Feb 03, 2020 at 01:17:40PM -0800, John Hubbard wrote: > On 2/3/20 5:58 AM, Kirill A. Shutemov wrote: > ... > >> @@ -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 > > > > Yes, I've changed it to "unsigned int", thanks. I'm confused. If nr_pages is more than UINT_MAX, this is endless loop. Hm?
On 2/3/20 1:55 PM, Kirill A. Shutemov wrote: > On Mon, Feb 03, 2020 at 01:17:40PM -0800, John Hubbard wrote: >> On 2/3/20 5:58 AM, Kirill A. Shutemov wrote: >> ... >>>> @@ -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 >>> >> >> Yes, I've changed it to "unsigned int", thanks. > > I'm confused. If nr_pages is more than UINT_MAX, this is endless loop. > Hm? > Oh, I've been afflicted with 64-bit tunnel vision. OK, make that "unsigned long" and "%ul". yikes. :) thanks,
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++) + 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++) { + 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) { @@ -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 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; 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;
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(-)