Commit 79dbf135 authored by Pavel Tatashin's avatar Pavel Tatashin Committed by Linus Torvalds
Browse files

selftests/vm: gup_test: fix test flag 

In gup_test both gup_flags and test_flags use the same flags field.
This is broken.

Farther, in the actual gup_test.c all the passed gup_flags are erased
and unconditionally replaced with FOLL_WRITE.

Which means that test_flags are ignored, and code like this always
performs pin dump test:

155  			if (gup->flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
156  				nr = pin_user_pages(addr, nr, gup->flags,
157  						    pages + i, NULL);
158  			else
159  				nr = get_user_pages(addr, nr, gup->flags,
160  						    pages + i, NULL);
161  			break;

Add a new test_flags field, to allow raw gup_flags to work.  Add a new
subcommand for DUMP_USER_PAGES_TEST to specify that pin test should be
performed.

Remove unconditional overwriting of gup_flags via FOLL_WRITE.  But,
preserve the previous behaviour where FOLL_WRITE was the default flag,
and add a new option "-W" to unset FOLL_WRITE.

Rename flags with gup_flags.

With the fix, dump works like this:

  root@virtme:/# gup_test  -c
  ---- page #0, starting from user virt addr: 0x7f8acb9e4000
  page:00000000d3d2ee27 refcount:2 mapcount:1 mapping:0000000000000000
  index:0x0 pfn:0x100bcf
  anon flags: 0x300000000080016(referenced|uptodate|lru|swapbacked)
  raw: 0300000000080016 ffffd0e204021608 ffffd0e208df2e88 ffff8ea04243ec61
  raw: 0000000000000000 0000000000000000 0000000200000000 0000000000000000
  page dumped because: gup_test: dump_pages() test
  DUMP_USER_PAGES_TEST: done

  root@virtme:/# gup_test  -c -p
  ---- page #0, starting from user virt addr: 0x7fd19701b000
  page:00000000baed3c7d refcount:1025 mapcount:1 mapping:0000000000000000
  index:0x0 pfn:0x108008
  anon flags: 0x300000000080014(uptodate|lru|swapbacked)
  raw: 0300000000080014 ffffd0e204200188 ffffd0e205e09088 ffff8ea04243ee71
  raw: 0000000000000000 0000000000000000 0000040100000000 0000000000000000
  page dumped because: gup_test: dump_pages() test
  DUMP_USER_PAGES_TEST: done

Refcount shows the difference between pin vs no-pin case.
Also change type of nr from int to long, as it counts number of pages.

Link: https://lkml.kernel.org/r/20210215161349.246722-14-pasha.tatashin@soleen.com


Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f68749ec

mm/gup_test.c

+10 −13
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ static int __gup_test_ioctl(unsigned int cmd, 
{

	ktime_t start_time, end_time;

	unsigned long i, nr_pages, addr, next;

	int nr;

	long nr;

	struct page **pages;

	int ret = 0;

	bool needs_mmap_lock =
@@ -126,37 +126,34 @@ static int __gup_test_ioctl(unsigned int cmd, 
			nr = (next - addr) / PAGE_SIZE;

		}



		/* Filter out most gup flags: only allow a tiny subset here: */

		gup->flags &= FOLL_WRITE;



		switch (cmd) {

		case GUP_FAST_BENCHMARK:

			nr = get_user_pages_fast(addr, nr, gup->flags,

			nr = get_user_pages_fast(addr, nr, gup->gup_flags,

						 pages + i);

			break;

		case GUP_BASIC_TEST:

			nr = get_user_pages(addr, nr, gup->flags, pages + i,

			nr = get_user_pages(addr, nr, gup->gup_flags, pages + i,

					    NULL);

			break;

		case PIN_FAST_BENCHMARK:

			nr = pin_user_pages_fast(addr, nr, gup->flags,

			nr = pin_user_pages_fast(addr, nr, gup->gup_flags,

						 pages + i);

			break;

		case PIN_BASIC_TEST:

			nr = pin_user_pages(addr, nr, gup->flags, pages + i,

			nr = pin_user_pages(addr, nr, gup->gup_flags, pages + i,

					    NULL);

			break;

		case PIN_LONGTERM_BENCHMARK:

			nr = pin_user_pages(addr, nr,

					    gup->flags | FOLL_LONGTERM,

					    gup->gup_flags | FOLL_LONGTERM,

					    pages + i, NULL);

			break;

		case DUMP_USER_PAGES_TEST:

			if (gup->flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)

				nr = pin_user_pages(addr, nr, gup->flags,

			if (gup->test_flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)

				nr = pin_user_pages(addr, nr, gup->gup_flags,

						    pages + i, NULL);

			else

				nr = get_user_pages(addr, nr, gup->flags,

				nr = get_user_pages(addr, nr, gup->gup_flags,

						    pages + i, NULL);

			break;

		default:
@@ -187,7 +184,7 @@ static int __gup_test_ioctl(unsigned int cmd, 


	start_time = ktime_get();



	put_back_pages(cmd, pages, nr_pages, gup->flags);

	put_back_pages(cmd, pages, nr_pages, gup->test_flags);



	end_time = ktime_get();

	gup->put_delta_usec = ktime_us_delta(end_time, start_time);

mm/gup_test.h

+2 −1
Original line number Diff line number Diff line
@@ -21,7 +21,8 @@ struct gup_test { 
	__u64 addr;

	__u64 size;

	__u32 nr_pages_per_call;

	__u32 flags;

	__u32 gup_flags;

	__u32 test_flags;

	/*

	 * Each non-zero entry is the number of the page (1-based: first page is

	 * page 1, so that zero entries mean "do nothing") from the .addr base.

tools/testing/selftests/vm/gup_test.c

+11 −4
Original line number Diff line number Diff line
@@ -37,13 +37,13 @@ int main(int argc, char **argv) 
{

	struct gup_test gup = { 0 };

	unsigned long size = 128 * MB;

	int i, fd, filed, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0;

	int i, fd, filed, opt, nr_pages = 1, thp = -1, repeats = 1, write = 1;

	unsigned long cmd = GUP_FAST_BENCHMARK;

	int flags = MAP_PRIVATE;

	char *file = "/dev/zero";

	char *p;



	while ((opt = getopt(argc, argv, "m:r:n:F:f:abctTLUuwSH")) != -1) {

	while ((opt = getopt(argc, argv, "m:r:n:F:f:abctTLUuwWSHp")) != -1) {

		switch (opt) {

		case 'a':

			cmd = PIN_FAST_BENCHMARK;
@@ -65,9 +65,13 @@ int main(int argc, char **argv) 
			 */

			gup.which_pages[0] = 1;

			break;

		case 'p':

			/* works only with DUMP_USER_PAGES_TEST */

			gup.test_flags |= GUP_TEST_FLAG_DUMP_PAGES_USE_PIN;

			break;

		case 'F':

			/* strtol, so you can pass flags in hex form */

			gup.flags = strtol(optarg, 0, 0);

			gup.gup_flags = strtol(optarg, 0, 0);

			break;

		case 'm':

			size = atoi(optarg) * MB;
@@ -93,6 +97,9 @@ int main(int argc, char **argv) 
		case 'w':

			write = 1;

			break;

		case 'W':

			write = 0;

			break;

		case 'f':

			file = optarg;

			break;
@@ -140,7 +147,7 @@ int main(int argc, char **argv) 


	gup.nr_pages_per_call = nr_pages;

	if (write)

		gup.flags |= FOLL_WRITE;

		gup.gup_flags |= FOLL_WRITE;



	fd = open("/sys/kernel/debug/gup_test", O_RDWR);

	if (fd == -1) {