Re: [PATCH 0/4] tests/xe: Add xe_page_reclaim test suite

["Summers, Stuart" <stuart.summers@intel.com>]

On Mon, 2026-04-06 at 18:42 +0000, Brian Nguyen wrote:
> Page Reclamation is a Xe3p feature that optimizes TLB invalidations
> by targeting only the specific physical pages being unmapped, rather
> than
> issuing a full PPC flush. With Page Reclamation, the driver maintains
> a
> Page Reclaim List (PRL), on the backing pages of a VMA range, which
> is
> passed into the hardware, limiting the flush to only the affected
> pages.
> 
> PRL supports up to 512 entries and beyond that results in a fallback
> to
> full TLB invalidation, and invalidating the PRL. The page reclamation
> test
> cases validate different combinations of the possible VMA ranges.
> 
> The primary source of validation of these cases is derived from the
> gt_stats in debugfs to confirm the proper PRL generation.

Just a high level question here, assuming the page reclamation is
happening at every invalidation and we should be getting coverage
generally across many of our tests (e.g. xe_* --r *invalidation*),
would it make sense to reduce the test scope here by just adding hooks
to the existing tests to check counters - and this kind of
infrastructure could potentially even go beyond just page
reclamation...

Or maybe another kind of related question, if we are adding some
explicit invalidation sizes/alignments here, are we not covering that
in some of the other tests like xe_vm?

Thanks,
Stuart

> 
> Brian Nguyen (4):
>   tests/xe: Add page reclaim test
>   tests/xe: Add random page reclaim subtest
>   tests/xe: Add transient display PRL skip
>   tests/xe: Add large VMA range tests for better coverage
> 
>  tests/intel/xe_page_reclaim.c | 826
> ++++++++++++++++++++++++++++++++++
>  tests/meson.build             |   1 +
>  2 files changed, 827 insertions(+)
>  create mode 100644 tests/intel/xe_page_reclaim.c
>