Hi, I have an app that uses the IVB bitstream hardware (via libva/intel-driver), and I have noticed some reported missed bsd IRQs in dmesg. After some testing I believe this only occurs when I run intel_gpu_top, so I'm assuming this is an issue with intel_gpu_top rather than the resolved bug 38862. I can reproduce the issue quickly by running intel_gpu_top at the same time as 8 instances of gem_dummy_reloc_loop on a loop (one instance is enough, but takes longer!). I only see missed bsd/blt ring IRQs, not render. I haven't seen any missed IRQs in the same test without intel_gpu_top. Of course a workaround is to only use intel_gpu_top while developing, and not on production devices since it's really a test tool, but it would be good to understand and it's definitely useful to know GPU load for real - as an aside, it's great that Intel releases such tools/source/documentation. Does anyone know whether this is expected behavior and/or how to fix it please? I am using a core i7 3612QE/HD4000 with a 3.5.0 kernel, libdrm 2.4.39 (Ubuntu 12.10 x64) and intel_gpu_top/gem_dummy_reloc_loop built from the very recent commit 3149531 of intel-gpu-tools. Thanks, Joe.
