Public issue detail

Runaway CPU investigation for python3.14: busy poll at XXH3_64bits_update

python3.14 is stuck in a likely busy poll loop: 7.68% of sampled CPU passed through XXH3_64bits_update, with repeated thread backtraces show 2 thread(s) around __syscall_cancel_arch () at ..<path>:56 and 1 thread(s) around __syscall_cancel_arch () at ..<path>:56.

highpackage: python3.14-minimalsource: python3.14score: 106reports: 1

Last seen: 2026-09-24 08:35 UTC. Public JSON: /v1/issues/01a0cc65-cb89-7dd1-bf79-3c60560d1b67

Technical snapshot

This is the clearest retained userspace thread cluster Fixer captured while the process was spinning.

Representative thread backtrace

  • Command: /usr/bin/python3 /usr/bin/unattended-upgrade
  • Why Fixer classified it this way: The trace repeatedly returns to a poll-family syscall without meaningful blocking, which suggests a busy event-loop wakeup.
  • Thread summary: thread backtraces show 2 thread(s) around __syscall_cancel_arch () at ..<path>:56 and 1 thread(s) around __syscall_cancel_arch () at ..<path>:56
  • Contention signals: event-loop-wakeups, gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory. warning: 56 ..<path>: No such file or directory
  • Repeated loop: wait4 -> pselect6 -> read
  • Top syscalls: lseek x82, newfstatat x82, pselect6 x71, read x70
  • Package: python3.14-minimal 3.14.7-4
  • Kernel: 7.1.8+deb14.1-amd64
  • Distribution: debian
__syscall_cancel_arch () at ..<path>:56
0x00007f3debaf09d4 in __internal_syscall_cancel (a1=..., a2=..., a3=..., a4=..., a5=..., a6=..., nr=...) at .<path>:49
0x00007f3debaf0a1d in __syscall_cancel (a1=..., a2=..., a3=..., a4=..., a5=..., a6=..., nr=...) at .<path>:75
0x00007f3debb6545e in __GI_ppoll (fds=..., nfds=..., timeout=..., sigmask=...) at ..<path>:42
0x00007f3de94fd47e in g_get_monotonic_time_ns () from target:<path>
0x00007f3de94fdd20 in g_main_context_iteration () from target:<path>
0x00007f3de94fdd71 in g_main_context_iteration () from target:<path>
0x00007f3de9532ea0 in g_private_set () from target:<path>

Possible duplicates

These are suggestions based on sanitized trigram similarity plus structured fields like package, subsystem, classification, and wait site. They are not auto-merged.

Runaway CPU investigation for python3.14: busy poll at void CppDeallocPtr<Configuration*>(_object*)

possible duplicate

python3.14 is stuck in a likely busy poll loop: 13.66% of sampled CPU passed through void CppDeallocPtr<Configuration*>(_object*), with repeated thread backtraces show 2 thread(s) around __syscall_cancel_arch () at ..<path>:56 and 1 thread(s) around 0x00007fbe346fe8a4 in void CppDeallocPtr<Configuration*>(_object*) () from target:<path>.

highpackage: python3.14-minimalsource: python3.14score: 106reports: 1similarity: 95%

Why this looks related: same classification, same package, same source package, same subsystem, same target

Last seen: 2026-10-22 19:27 UTC. Public page: /issues/019f786b-ccc8-7e90-8fee-186a079214f0. Public JSON: /v1/issues/019f786b-ccc8-7e90-8fee-186a079214f0

Runaway CPU investigation for python3.13: busy poll at idle_cpu

possible duplicate

python3.13 is stuck in a likely busy poll loop: 40.65% of sampled CPU passed through idle_cpu, with repeated thread backtraces show 1 thread(s) around 0x00007f1c6e7efe92 in pthread_attr_destroy () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 2successful triagesimilarity: 76%

Why this looks related: same classification, same subsystem, same wait site

Last seen: 2026-10-04 02:36 UTC. Public page: /issues/019dfead-0293-7062-b24e-c9b04c2f1edb. Public JSON: /v1/issues/019dfead-0293-7062-b24e-c9b04c2f1edb

Runaway CPU investigation for python3.13: busy poll at read_tsc

possible duplicate

python3.13 is stuck in a likely busy poll loop: 50.00% of sampled CPU passed through read_tsc, with repeated thread backtraces show 1 thread(s) around 0x00007f1c6e7efe92 in pthread_attr_destroy () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 2successful triagesimilarity: 75%

Why this looks related: same classification, same subsystem, same wait site

Last seen: 2026-10-10 01:56 UTC. Public page: /issues/019da8df-cd0c-7880-ab1e-6dd908d64437. Public JSON: /v1/issues/019da8df-cd0c-7880-ab1e-6dd908d64437

Runaway CPU investigation for python3.14: file not found retry at void CppDeallocPtr<Configuration*>(_object*)

possible duplicate

python3.14 is stuck in a likely file not found retry loop: 11.35% of sampled CPU passed through void CppDeallocPtr<Configuration*>(_object*), with repeated thread backtraces show 2 thread(s) around __syscall_cancel_arch () at ..<path>:56 and 1 thread(s) around __ctype_b_loc () at ..<path>:43.

highpackage: python3.14-minimalsource: python3.14score: 106reports: 1similarity: 73%

Why this looks related: same package, same source package, same subsystem, same target

Last seen: 2026-10-12 18:34 UTC. Public page: /issues/019f6914-4c2c-7460-a165-72bb0ce46cbd. Public JSON: /v1/issues/019f6914-4c2c-7460-a165-72bb0ce46cbd

Runaway CPU investigation for python3.13: busy poll at _PyEval_FrameClearAndPop

possible duplicate

python3.13 is stuck in a likely busy poll loop: 50.00% of sampled CPU passed through _PyEval_FrameClearAndPop, with repeated thread backtraces show 1 thread(s) around 0x00007f1c6e7efe92 in pthread_attr_destroy () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 2successful triagesimilarity: 70%

Why this looks related: same classification, same subsystem, same wait site

Last seen: 2026-10-22 19:28 UTC. Public page: /issues/019dd062-04a8-7e03-b3a3-5bb273aa2f42. Public JSON: /v1/issues/019dd062-04a8-7e03-b3a3-5bb273aa2f42

Runaway CPU investigation for postgres: busy poll at sqlite3VdbeExec

possible duplicate

postgres is stuck in a likely busy poll loop: 9.57% of sampled CPU passed through sqlite3VdbeExec, with repeated thread backtraces show 1 thread(s) around 0x00007f3dd70ac60d in select () from target:<path>.

highscore: 106reports: 1similarity: 69%

Why this looks related: same classification, same subsystem, same wait site

Last seen: 2026-10-02 18:03 UTC. Public page: /issues/019f9de5-ae93-70a0-b43c-cc5fcfe33721. Public JSON: /v1/issues/019f9de5-ae93-70a0-b43c-cc5fcfe33721

Published attempts

No public attempts have been published for this issue yet.

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