Per-card measurement was unreachable for every card but ordinal 0: the driver
set HIP_VISIBLE_DEVICES=N and still passed N as the device argument, so the
probe called hipSetDevice(N) on a runtime where the mask left only ordinal 0.
The bats stub reported the env var rather than the argument it received, so
the suite asserted the mask was set and never noticed the collision.
- one selector: the ordinal is passed as argv, the mask is never set
- a probe that fails is now exit 5 and names probe + device; the sweep still
measures the remaining cards instead of swallowing the failure
- the guard fails closed when `fuser` is missing (gpu_busy_percent reads 0 for
a resident-but-idle service), with PCIE_PROBE_FUSER as the test seam
- stub probes now model the HIP mask rule; the pre-existing per-device test
goes red against the old driver, which is the regression proof
Refs #60
The RDNA4 offload campaign left three HIP probes and a driver sitting loose in
$HOME, where the next agent cannot find them and a stray `rm -rf` ends them. They
answer a recurring question on the R9700 box — is decode limited by the link or by
the engine's read path — so they move into scripts/probes/ with a driver, tests,
and a page.
Two things changed in the code, not just the address:
- The driver measures only after a guard that runs BEFORE anything is built:
gpu_busy_percent over PCIE_PROBE_MAX_BUSY, or any process holding /dev/kfd, is a
refusal (exit 3) rather than a measurement. A benchmark taken beside a live
endpoint is both disruptive and worthless, and silently unloading a production
service is not a tool's decision — --force is the human saying otherwise. The
refusal-before-build ordering is pinned by a test, because the sysfs and kfd
paths are overridable and a refusal is otherwise untestable off the card box.
- hip_smoke.hip and pcie_probe.hip called hipGetDeviceProperties, which SEGFAULTS
on this ROCm build even though hipGetDeviceCount works; only pcie_bw.hip avoided
it, and that is the one that produced the campaign's numbers. Device identity now
comes from the sysfs topology block the driver prints, so all three probes are
runnable on the build we ship. Verified here: refusal on a real busy APU (exit 3),
missing toolchain (exit 4), missing sources (exit 2). Compile-and-run still needs
the box with hipcc.
Refs #53
Frank