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mm/gup_benchmark: support pin_user_pages() and related calls

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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 <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200211001536.1027652-10-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
John Hubbard 2020-04-01 21:05:41 -07:00 committed by Linus Torvalds
parent 1970dc6f52
commit 41c45d37b9
2 changed files with 80 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
mm/gup_benchmark.c
View File

@ -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;

15
tools/testing/selftests/vm/gup_benchmark.c
View File

@ -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;