tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c
Extension
.c
Size
1763 bytes
Lines
78
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

if (munmap(addr, SIZE)) {
			perror("munmap");
			return 1;
		}
	}

	p = mmap(addr, SIZE, PROT_READ | PROT_WRITE,
		 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
	if (p == MAP_FAILED) {
		printf("Mapping failed @ %p\n", addr);
		perror("mmap");
		return 1;
	}

	/*
	 * Either a user or kernel access is sufficient to trigger the bug.
	 * A kernel access is easier to spot & debug, as it will trigger the
	 * softlockup or RCU stall detectors, and when the system is kicked
	 * into xmon we get a backtrace in the kernel.
	 *
	 * A good option is:
	 *  getcwd(p, SIZE);
	 *
	 * For the purposes of this testcase it's preferable to spin in
	 * userspace, so the harness can kill us if we get stuck. That way we
	 * see a test failure rather than a dead system.
	 */
	*p = 0xf;

	munmap(addr, SIZE);

	return 0;
}

static int test_main(void)
{
	int i;

	/* 10,000 because it's a "bunch", and completes reasonably quickly */
	for (i = 0; i < 10000; i++)
		if (test_body())
			return 1;

	return 0;
}

int main(void)
{
	return test_harness(test_main, "hugetlb_vs_thp");
}

Annotation

Implementation Notes