[PATCH 0/4] Let userspace explicitly trigger memory reclaims

[Nicolas Frattaroli <nicolas.frattaroli@collabora.com>]

RAM is not, in fact, cheap. Especially on embedded systems with a low
amount of memory, but known and well-defined userspace, more explicit
resource management can lead to better utilisation patterns. As an
example, a resource manager process on a purpose-built device may wish
to launch, and then explicitly swap out, memory of processes that are
kept "warm", to improve perceived startup latency of individual
full-screen applications without making the kernel figure out the usage
pattern from observation alone in order to swap out the right pages.

To allow for this explicit control in the context of panthor's GPU
memory, add two new sysfs knobs. The first, mem_reclaim, runs an
explicit priv BO reclaim cycle on the TGID written to it.

The second, mem_claim, does the opposite: it swaps BOs back into active
memory.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
Nicolas Frattaroli (4):
      drm/panthor: Add freed_sz parameter to reclaim_priv_bos
      MAINTAINERS: Add sysfs ABI docs to list of panthor files
      drm/panthor: Add explicit memory reclaim sysfs knob
      drm/panthor: Add explicit memory claim sysfs knob

 Documentation/ABI/testing/sysfs-driver-panthor-mem | 34 ++++++++
 MAINTAINERS                                        |  1 +
 drivers/gpu/drm/panthor/panthor_drv.c              | 93 ++++++++++++++++++++++
 drivers/gpu/drm/panthor/panthor_gem.c              |  7 +-
 drivers/gpu/drm/panthor/panthor_gem.h              |  1 +
 drivers/gpu/drm/panthor/panthor_mmu.c              | 70 +++++++++++++++-
 drivers/gpu/drm/panthor/panthor_mmu.h              |  4 +
 7 files changed, 205 insertions(+), 5 deletions(-)
---
base-commit: 2c4b906cd135bbb44855287d0d0eff0ee0b47afe
change-id: 20260506-panthor-explicit-reclaim-3dffed028d8c

Best regards,
--  
Nicolas Frattaroli <nicolas.frattaroli@collabora.com>