Feed a fresh i915 mmap into a read(perf_fd) to teach lockdep about the
potential lock chains should we take a pagefault into our vm_fault
handlers from within perf.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
---
tests/perf_pmu.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/tests/perf_pmu.c b/tests/perf_pmu.c
index 259670f4b..1d6681d80 100644
--- a/tests/perf_pmu.c
+++ b/tests/perf_pmu.c
@@ -1827,6 +1827,35 @@ accuracy(int gem_fd, const struct intel_execution_engine2 *e,
assert_within(100.0 * busy_r, 100.0 * expected, 2);
}
+static void *create_mmap(int gem_fd, const struct mmap_offset *t, int sz)
+{
+ uint32_t handle;
+ void *ptr;
+
+ handle = gem_create(gem_fd, sz);
+ ptr = __gem_mmap_offset(gem_fd, handle, 0, sz, PROT_WRITE, t->type);
+ gem_close(gem_fd, handle);
+
+ return ptr;
+}
+
+static void
+faulting_read(int gem_fd, const struct mmap_offset *t)
+{
+ void *ptr;
+ int fd;
+
+ ptr = create_mmap(gem_fd, t, 4096);
+ igt_require(ptr != NULL);
+
+ fd = open_pmu(gem_fd, I915_PMU_ENGINE_BUSY(0, 0));
+ igt_require(fd != -1);
+ igt_assert_eq(read(fd, ptr, 4096), 2 * sizeof(uint64_t));
+ close(fd);
+
+ munmap(ptr, 4096);
+}
+
#define test_each_engine(T, i915, e) \
igt_subtest_with_dynamic(T) __for_each_physical_engine(i915, e) \
igt_dynamic_f("%s", e->name)
@@ -1860,6 +1889,16 @@ igt_main
igt_subtest("invalid-init")
invalid_init(fd);
+ igt_subtest_with_dynamic("faulting-read") {
+ for_each_mmap_offset_type(fd, t) {
+ if (!gem_has_mmap_offset_type(fd, t))
+ continue;
