Major update for ECRTS'25: fix TPC to GPU mapping and add a "supreme" mask

These updates are featured in the paper:

J. Bakita and J. H. Anderson, “Hardware Compute Partitioning on
NVIDIA GPUs for Composable Systems”, Proceedings of the 37th
Euromicro Conference on Real-Time Systems (ECRTS), to appear,
Jul 2025.

They:
1. Fix reported GPC to TPC mappings (requires nvdebug update).
2. Add support for a "supreme" mask, which overrides all others and
   can be set on a per-process basis via an environment variable,
   and optionally modified at runtime via the nvtaskset utility.
3. Add test for the supreme mask.

1 files changed, 3 insertions, 1 deletions

diff --git a/libsmctrl.h b/libsmctrl.h
index b85c0c7..45d2cd7 100644
--- a/libsmctrl.h
+++ b/libsmctrl.h
@@ -1,5 +1,5 @@
 /**
- * Copyright 2022-2024 Joshua Bakita
+ * Copyright 2022-2025 Joshua Bakita
  * Library to control TPC masks on CUDA launches. Co-opts preexisting debug
  * logic in the CUDA driver library, and thus requires a build with -lcuda.
  */
@@ -58,11 +58,13 @@ extern void libsmctrl_set_next_mask(uint64_t mask);
 // Get number of GPCs for devices number `dev`, and a GPC-indexed array
 // containing masks of which TPCs are associated with each GPC.
 // Note that the `nvdebug` module must be loaded to use this function.
+// Note that at least one GPU context must be active to use this function.
 // @param  num_enabled_gpcs (out) Location to store number of GPCs in
 // @param  tpcs_for_gpc     (out) Pointer to store pointer to output buffer at
 // @param  dev               (in) `nvdebug` device ID
 // @return 0 on success, `errno`-compatible error code on failure
 extern int libsmctrl_get_gpc_info(uint32_t* num_enabled_gpcs, uint64_t** tpcs_for_gpc, int dev);
+extern int libsmctrl_get_gpc_info_ext(uint32_t* num_enabled_gpcs, uint128_t** tpcs_for_gpc, int dev);
 // Get total number of TPCs on device number `dev`. Requires `nvdebug`.
 // @param  num_tpcs        (out) Location to store number of TPCs at
 // @param  dev              (in) `nvdebug` device ID