Re: [PATCH 5/5] selftests: prctl: introduce tests for disabling THPs except for madvise

quoted

+	res = test_mmap_thp(COLLAPSE, pmdsize);
+	ASSERT_EQ(res, 1);

Seems res is not being used other than saving the return value for assertions.
Why don't you do the assertion at once, e.g., ASSERT_EQ(test_mmap_thp(...), 1)?
No strong opinion, but I think that could make code shorter and easier to read.

Yeah this is on purpose, I found it easier to evaluate what the output should be
if I wrote code like this. As compiler will likely just optimize it out (although
we dont really care about performance :) ), although others might find without res
better.
I think you had mentioned it in the earlier thread as well. I will remove it.>> +}

quoted

+
+TEST_F(prctl_thp_disable_except_madvise, nofork)
+{
+	int res = 0;
+
+	res = prctl(PR_SET_THP_DISABLE, 1, PR_THP_DISABLE_EXCEPT_ADVISED, NULL, NULL);
+	ASSERT_EQ(res, 0);

Again, I think 'res' can be removed.

quoted

+	prctl_thp_disable_except_madvise(_metadata, self->pmdsize);
+}
+
+TEST_F(prctl_thp_disable_except_madvise, fork)
+{
+	int res = 0, ret = 0;
+	pid_t pid;
+
+	res = prctl(PR_SET_THP_DISABLE, 1, PR_THP_DISABLE_EXCEPT_ADVISED, NULL, NULL);
+	ASSERT_EQ(res, 0);

Ditto.

quoted

+
+	/* Make sure prctl changes are carried across fork */
+	pid = fork();
+	ASSERT_GE(pid, 0);
+
+	if (!pid)
+		prctl_thp_disable_except_madvise(_metadata, self->pmdsize);
+
+	wait(&ret);
+	if (WIFEXITED(ret))
+		ret = WEXITSTATUS(ret);
+	else
+		ret = -EINVAL;
+	ASSERT_EQ(ret, 0);
+}
+
 FIXTURE(prctl_thp_disable_completely)
 {
 	struct thp_settings settings;
-- 
2.47.3

Thanks,
SJ