Re: [PATCH] selftests: iommu: add config needed for iommufd_fail_nth

[Jason Gunthorpe <jgg@ziepe.ca>]

On Tue, Mar 26, 2024 at 06:09:34PM +0500, Muhammad Usama Anjum wrote:
> Even after applying this config patch and following snippet (which doesn't
> terminate the program if mmap doesn't allocate exactly as the hint), I'm
> finding failed tests.
> 
> @@ -1746,7 +1748,7 @@ FIXTURE_SETUP(iommufd_dirty_tracking)
>         assert((uintptr_t)self->buffer % HUGEPAGE_SIZE == 0);
>         vrc = mmap(self->buffer, variant->buffer_size, PROT_READ | PROT_WRITE,
>                    mmap_flags, -1, 0);
> -       assert(vrc == self->buffer);
> +       assert(vrc == self->buffer);// ???
> 
> On x86:
> # Totals: pass:176 fail:4 xfail:0 xpass:0 skip:0 error:0
> On ARM64:
> # Totals: pass:166 fail:14 xfail:0 xpass:0 skip:0 error:0
> 
> The log files are attached.

You probably don't have enough transparent huge pages available to the process

      echo 1024 > /proc/sys/vm/nr_hugepages

Jason