Title: [3.15] gh-149584: Fix excessive overhead in the Tachyon profiler regarding the cache behavior (GH-149649) by miss-islington · Pull Request #150152 · python/cpython · GitHub
Open Graph Title: [3.15] gh-149584: Fix excessive overhead in the Tachyon profiler regarding the cache behavior (GH-149649) by miss-islington · Pull Request #150152 · python/cpython
X Title: [3.15] gh-149584: Fix excessive overhead in the Tachyon profiler regarding the cache behavior (GH-149649) by miss-islington · Pull Request #150152 · python/cpython
Description: Use exact remote reads for interpreter state, thread state, and interpreter frame structs instead of pulling full remote pages into the profiler page cache. This matches the core change from #149585. The profiler clears the page cache between samples, so live entries are always packed at the front. Track the live count and only clear/search that prefix instead of scanning all 1024 slots on the hot path. Use the frame cache to predict the next thread state and top frame address, then batch interpreter/thread/frame reads with process_vm_readv when profiling a Linux target. Reuse prefetched frame buffers in the frame walker when the prediction is valid. Cache the last FrameInfo tuple per code object/instruction offset, reuse cached thread id objects, and append cached parent frames directly on full frame-cache hits. This cuts Python allocation churn in the steady-state profiler path. (cherry picked from commit 661df25) Co-authored-by: Pablo Galindo Salgado Pablogsal@gmail.com Issue: gh-149584
Open Graph Description: Use exact remote reads for interpreter state, thread state, and interpreter frame structs instead of pulling full remote pages into the profiler page cache. This matches the core change from #14958...
X Description: Use exact remote reads for interpreter state, thread state, and interpreter frame structs instead of pulling full remote pages into the profiler page cache. This matches the core change from #14958...
Opengraph URL: https://github.com/python/cpython/pull/150152
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