Fix segfault with -O0-compiled kernels #13
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`kernels_[blitType]` yields a null function pointer in `KernelBlitManager::initHeap` due to `KernelBlitManager::createProgram` not initializing all the kernels because of broken layout invariants. `KernBlitManager::NumBlitKernels` has two possible return values: `BlitTotal, and BlitLinearTotal` which are sentinels. These sentinels are used in `KernelBlitManager::createProgram` to initialize the `kernels_` array. It correctly initializes `[0, NumBlitKernels())`, but `InitHeap` is > `NumBlitKernels`, so the `InitHeap` kernel is not loaded. Thus, when images are disabled, and a kernel has an `hidden_heap_v1` entry, the `InitHeap` blitkernel is not loaded, and `kernelBlitManager::initHeap` subsequently gets a null pointer. The kernel always has such `hidden_heap_v1` descriptor entry at -O0, but I believe it's possible (unconfirmed) for this situation to occur in other circumstances. The fix is simply to ensure the `InitHeap` enumeration has a numeric value *less than* `BlitLinearTotal`. n.b. This bug does not exist on the 5.7 release, but it looks like that's by chance.
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cc'ing: @gandryey @chrispaquot @saleelk |
npmiller
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May 30, 2024
This was tracked down to a bug in ROCm that seems to be fixed with newer versions, and the CI is now on ROCm 6+ so these should be fine. ROCm ticket: ROCm/clr#13 The reduce over group test works on W6800 and MI210, but it seems for gfx1031 it reports not supporting shared USM, note that HIP for gfx1031 isn't officially supported by AMD.
steffenlarsen
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Jun 7, 2024
This was tracked down to a bug in ROCm that seems to be fixed with newer versions, and the CI is now on ROCm 6+ so these should be fine. ROCm ticket: ROCm/clr#13 The reduce over group test works on W6800 and MI210, but it seems for gfx1031 it reports not supporting shared USM, note that HIP for gfx1031 isn't officially supported by AMD. --------- Co-authored-by: Steffen Larsen <[email protected]>
ianayl
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Jun 13, 2024
This was tracked down to a bug in ROCm that seems to be fixed with newer versions, and the CI is now on ROCm 6+ so these should be fine. ROCm ticket: ROCm/clr#13 The reduce over group test works on W6800 and MI210, but it seems for gfx1031 it reports not supporting shared USM, note that HIP for gfx1031 isn't officially supported by AMD. --------- Co-authored-by: Steffen Larsen <[email protected]>
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kernels_[blitType]yields a null function pointer inKernelBlitManager::initHeapdue toKernelBlitManager::createProgramnot initializing all the kernels because of broken layout invariants.KernBlitManager::NumBlitKernelshas two possible return values:BlitTotal, andBlitLinearTotalwhich are sentinels. These sentinels are used inKernelBlitManager::createProgramto initialize thekernels_array. It correctly initializes[0, NumBlitKernels()), butInitHeapis >NumBlitKernels, so theInitHeapkernel is not loaded.Thus, when images are disabled, and a kernel has an
hidden_heap_v1entry, theInitHeapblitkernel is not loaded, andkernelBlitManager::initHeapsubsequently gets a null pointer. The kernel always has suchhidden_heap_v1descriptor entry at -O0, but I believe it's possible (unconfirmed) for this situation to occur in other circumstances.The fix is simply to ensure the
InitHeapenumeration has a numeric value less thanBlitLinearTotal.n.b. This bug does not exist on the 5.7 release, but it looks like that's by chance.