Re: [PATCH v4 09/14] selftests: harness: Move teardown conditional into test metadata

On Thu, Jun 12, 2025 at 11:53:24AM -0700, Nicolin Chen wrote:

@@ -2022,7 +2023,19 @@ FIXTURE_SETUP(iommufd_dirty_tracking) self->fd = open("/dev/iommu", O_RDWR); ASSERT_NE(-1, self->fd);

•   rc = posix_memalign(&self->buffer, HUGEPAGE_SIZE, variant->buffer_size);
  

•   if (variant->hugepages) {
  

•           /*
  

•            * Allocation must be aligned to the HUGEPAGE_SIZE, because the
  

•            * following mmap() will automatically align the length to be a
  

•            * multiple of the underlying huge page size. Failing to do the
  

•            * same at this allocation will result in a memory overwrite by
  

•            * the mmap().
  

•            */
  

•           size = __ALIGN_KERNEL(variant->buffer_size, HUGEPAGE_SIZE);
  

•   } else {
  

•           size = variant->buffer_size;
  

•   }
  

•   rc = posix_memalign(&self->buffer, HUGEPAGE_SIZE, size);
    if (rc || !self->buffer) {
            SKIP(return, "Skipping buffer_size=%lu due to errno=%d",
                       variant->buffer_size, rc);
  
  

It can just upsize the allocation, i.e. the test case will only use the first 64M or 128MB out of the reserved 512MB huge page.

The MAP_HUGETLBFS is required that is the whole point of what it is doing..

Jason