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Module intel

gpuviewer_core

Module intel 

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Intel Linux backend — hand-rolled std::fs readers over sysfs/fdinfo, no library linkage (no Level Zero, no IGCL: per docs/research/02 their Linux coverage is gappy and root-gated; plain fdinfo+sysfs is the strong path).

The defining caveat: i915 and xe are two different worlds (research 02). Same vendor, two in-tree drivers, different fdinfo keys AND different sysfs freq layouts — every read below is dispatched on a per-device [Dialect] detected from the uevent:

  • i915 (Gen9 → Meteor Lake, DG2 default): fdinfo drm-engine-* cumulative busy-ns (kernel 5.19+), per-process memory regions named local0/system0 (6.8+), card-level gt_*_freq_mhz files, dGPU-only lmem_total_bytes, hwmon package temp on temp1_input (6.12+).
  • xe (Lunar Lake, Battlemage+): fdinfo drm-cycles-* / drm-total-cycles-* GT-clock counters (6.11+), memory regions named vram0/system/gtt (6.8+), device/tile0/gt0/freq0/* freq files, NO VRAM-total sysfs at all, hwmon package temp on temp2_input — there is NO temp1, and temp3 is the VRAM sensor (6.15+).

Per the domain rules in CLAUDE.md:

  • Every path derives from a root-dir parameter (with_root), so the whole backend runs against committed fixture trees; init() is just with_root("/").
  • A missing file or unparsable value is None, never a failure — an iGPU has NO hwmon at all, so temp/power/fan absence is the NORMAL case, not a broken device. hwmon itself is effectively dGPU-only and recent-kernel-gated (i915 fan/temp 6.12+; xe temps 6.15+, fans 6.16+).
  • Device-level utilization is deliberately None: the i915/xe perf PMU needs root/CAP_PERFMON (intel_gpu_top’s infamous “Failed to initialize PMU”; the xe PMU only exists since 6.15), and summing fdinfo across clients we may not be able to see would understate — an invented number is worse than an honest absence.
  • The xe per-process utilization math is NOT the i915 math: Δbusy-cycles over Δtotal-cycles, never over wall time — see [cycles_util_pct].
  • Other users’ fdinfo needs root/CAP_SYS_PTRACE, so unprivileged runs carry an honest “your processes only” process_hint (same model as the AMD backend).

Structs§

IntelBackend