** Summary changed: - [i5-3230] Crash/hang/graphical artifacts in pyopencl + [i5-3230] Tight pyopencl.clmath loops cause out-of-memory system hang
** Description changed: - pyopencl is partly or wholly unusable on an Intel i5-3230 integrated - GPU: + In beignet (not pocl), tight loops involving OpenCL array creation and + destruction, eg. repeated bCL=aCL+bCL (or other pyopencl.clmath + operations) or repeated pyopencl.enqueue_copy(cq0,bCL.data,aCL.data), + often hang the whole system, after a number of operations consistent + with memory exhaustion. - beignet 0.3 (trusty default): - pyopencl.elementwise.ElementwiseKernel draws dotted stripes across the screen, and gives wrong results - pyopencl.clmath segfaults Python + As waiting for queued operations to finish + (pyopencl.enqueue_barrier(cq0).wait()) before attempting more avoids the + bug, but dependencies between the operations (as in the bCL=aCL+bCL + example) do not, this is probably a result of the "allocate memory" step + being separate from, and faster than, the "do the operation" step, so + being able to run ahead until it uses up all the memory. - beignet 0.8 (utopic source, recompiled in trusty) and 0.9 (upstream git head): - pyopencl.elementwise.ElementwiseKernel works - pyopencl.clmath hangs the entire system (screen frozen, any playing sounds repeating in ~0.5sec loop, requires Alt+SysRq+b reboot; System Monitor shows no abnormal memory usage before the hang, but I don't know if it counts GPU memory) - - To reproduce: python pocl_test.py - - I'm guessing this is a beignet rather than pyopencl bug, as pyopencl - worked on my previous (nvidia) system and a normal application shouldn't - be able to hang the whole system. - - ProblemType: Bug - DistroRelease: Ubuntu 14.04 - Package: beignet (not installed) - ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4 - Uname: Linux 3.13.0-32-generic x86_64 - ApportVersion: 2.14.1-0ubuntu3.2 - Architecture: amd64 - CurrentDesktop: Unity - Date: Thu Aug 7 17:18:35 2014 - EcryptfsInUse: Yes - InstallationDate: Installed on 2014-08-01 (6 days ago) - InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64+mac (20140722.2) - SourcePackage: beignet - UpgradeStatus: No upgrade log present (probably fresh install) + (Note that while the above wait() can be used as a workaround for this + bug, it is usually faster to avoid frequent memory allocation + altogether, by reusing existing arrays; for pyopencl.clmath, this means + using pyopencl.tools.MemoryPool.) ** Attachment added: "arraybug_test.py" https://bugs.launchpad.net/ubuntu/+source/beignet/+bug/1354086/+attachment/4308304/+files/arraybug_test.py -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1354086 Title: [i5-3230] Tight pyopencl.clmath loops cause out-of-memory system hang To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/beignet/+bug/1354086/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
