GUP'ing pages should get the same pages, test it. In case of FOLL_EXCLUSIVE, the second pin should fail to get any pages.
Note: this change ought to be refactored to pull out the GUP'ing bits that's duplicated between the original and the second GUP.
Signed-off-by: Elliot Berman quic_eberman@quicinc.com --- mm/gup_test.c | 86 +++++++++++++++++++++++++++++++++++ mm/gup_test.h | 1 + tools/testing/selftests/mm/gup_test.c | 5 +- 3 files changed, 91 insertions(+), 1 deletion(-)
diff --git a/mm/gup_test.c b/mm/gup_test.c index 9c6b8c93e44a7..28cc422b60b78 100644 --- a/mm/gup_test.c +++ b/mm/gup_test.c @@ -86,6 +86,89 @@ static void verify_exclusive_pinned(unsigned int gup_flags, struct page **pages, } }
+static int verify_gup_twice(unsigned int cmd, struct gup_test *gup, + struct page **expected_pages, + unsigned long expected_nr_pages) +{ + unsigned long i, nr_pages, addr, next; + long nr; + struct page **pages __free(kfree) = NULL; + int ret = 0; + + nr_pages = gup->size / PAGE_SIZE; + pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + i = 0; + nr = gup->nr_pages_per_call; + for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) { + if (nr != gup->nr_pages_per_call) + break; + + next = addr + nr * PAGE_SIZE; + if (next > gup->addr + gup->size) { + next = gup->addr + gup->size; + nr = (next - addr) / PAGE_SIZE; + } + + switch (cmd) { + case GUP_FAST_BENCHMARK: + nr = get_user_pages_fast(addr, nr, gup->gup_flags, + pages + i); + break; + case GUP_BASIC_TEST: + nr = get_user_pages(addr, nr, gup->gup_flags, pages + i); + break; + case PIN_FAST_BENCHMARK: + nr = pin_user_pages_fast(addr, nr, gup->gup_flags, + pages + i); + break; + case PIN_BASIC_TEST: + nr = pin_user_pages(addr, nr, gup->gup_flags, pages + i); + break; + case PIN_LONGTERM_BENCHMARK: + nr = pin_user_pages(addr, nr, + gup->gup_flags | FOLL_LONGTERM, + pages + i); + break; + default: + pr_err("cmd %d not supported for %s\n", cmd, __func__); + return -EINVAL; + } + + if (nr <= 0) + break; + i += nr; + } + + nr_pages = i; + + if (gup->gup_flags & FOLL_EXCLUSIVE) { + if (WARN(nr_pages, + "Able to acquire exclusive pin twice for %ld of %ld pages", + nr_pages, expected_nr_pages)) { + dump_page(pages[0], + "gup_test: verify_gup_twice() test"); + ret = -EIO; + } + } else if (nr_pages != expected_nr_pages) { + pr_err("%s: Expected %ld pages, got %ld\n", __func__, + expected_nr_pages, nr_pages); + ret = -EIO; + } else { + for (i = 0; i < nr_pages; i++) { + if (WARN(pages[i] != expected_pages[i], + "pages[%lu] mismatch\n", i)) + break; + } + } + + put_back_pages(cmd, pages, nr_pages, gup->test_flags); + + return ret; +} + static void dump_pages_test(struct gup_test *gup, struct page **pages, unsigned long nr_pages) { @@ -210,6 +293,9 @@ static int __gup_test_ioctl(unsigned int cmd, if (cmd == DUMP_USER_PAGES_TEST) dump_pages_test(gup, pages, nr_pages);
+ if (gup->test_flags & GUP_TEST_FLAG_GUP_TWICE) + ret = verify_gup_twice(cmd, gup, pages, nr_pages); + start_time = ktime_get();
put_back_pages(cmd, pages, nr_pages, gup->test_flags); diff --git a/mm/gup_test.h b/mm/gup_test.h index 5b37b54e8bea6..fcd41919b0159 100644 --- a/mm/gup_test.h +++ b/mm/gup_test.h @@ -17,6 +17,7 @@ #define GUP_TEST_MAX_PAGES_TO_DUMP 8
#define GUP_TEST_FLAG_DUMP_PAGES_USE_PIN 0x1 +#define GUP_TEST_FLAG_GUP_TWICE 0x2
struct gup_test { __u64 get_delta_usec; diff --git a/tools/testing/selftests/mm/gup_test.c b/tools/testing/selftests/mm/gup_test.c index bdeaac67ff9aa..b4b10c8338f80 100644 --- a/tools/testing/selftests/mm/gup_test.c +++ b/tools/testing/selftests/mm/gup_test.c @@ -98,7 +98,7 @@ int main(int argc, char **argv) pthread_t *tid; char *p;
- while ((opt = getopt(argc, argv, "m:r:n:F:f:abcj:tTLUuwWSHpz")) != -1) { + while ((opt = getopt(argc, argv, "m:r:n:F:f:abcj:dtTLUuwWSHpz")) != -1) { switch (opt) { case 'a': cmd = PIN_FAST_BENCHMARK; @@ -172,6 +172,9 @@ int main(int argc, char **argv) /* fault pages in gup, do not fault in userland */ touch = 1; break; + case 'd': + gup.test_flags |= GUP_TEST_FLAG_GUP_TWICE; + break; default: ksft_exit_fail_msg("Wrong argument\n"); }