Public issue detail

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

python3.13 is stuck in a likely busy poll loop: 7.43% of sampled CPU passed through __radix_tree_lookup, with repeated thread backtraces show 2 thread(s) around 0x00007fa228821ffe in ?? () from target:<path> and 1 thread(s) around 0x00007fa228821ffe in ?? () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 1

Last seen: 2026-07-05 13:59 UTC. Public JSON: /v1/issues/019f2bc3-de08-7860-a55b-b87e802981f1

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 0x00007fa228821ffe in ?? () from target:<path> and 1 thread(s) around 0x00007fa228821ffe in ?? () from target:<path>
  • Contention signals: event-loop-wakeups, gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory.
  • Repeated loop: read -> wait4 -> pselect6
  • Top syscalls: pselect6 x51, read x50, wait4 x50, ppoll x2
  • Package: python3.13-minimal 3.13.12-1
  • Kernel: 6.17.10+deb14-amd64
  • Distribution: debian
0x00007fa228821ffe in ?? () from target:<path>
0x00007fa2288167a4 in ?? () from target:<path>
0x00007fa2288167ed in ?? () from target:<path>
0x00007fa22888c29e in ppoll () from target:<path>
0x00007fa22782daa4 in ?? () from target:<path>
0x00007fa22782e190 in g_main_context_iteration () from target:<path>
0x00007fa22782e1e1 in ?? () from target:<path>
0x00007fa2278604f6 in ?? () 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 python3.13: busy poll at unresolved offset in libc.so.6

possible duplicate

python3.13 is stuck in a likely busy poll loop: 6.41% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 1 thread(s) around 0x00007fdd05c9b72e in ?? () and 1 thread(s) around 0x00007fdd05c9b72e in ?? ().

highpackage: python3.13-minimalsource: python3.13score: 106reports: 3patch attempt readysimilarity: 99%

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

Last seen: 2026-07-09 19:56 UTC. Public page: /issues/019d7cef-46dd-7541-b939-9ba6872fbf76. Public JSON: /v1/issues/019d7cef-46dd-7541-b939-9ba6872fbf76

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

possible duplicate

python3.13 is stuck in a likely busy poll loop: 50.00% of sampled CPU passed through _PyEval_EvalFrameDefault, with repeated thread backtraces show 1 thread(s) around 0x00007f091ce537d2 in ?? () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 2patch attempt readysimilarity: 99%

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

Last seen: 2026-07-02 23:40 UTC. Public page: /issues/019dda71-4897-7d62-853d-31f4899d9f8e. Public JSON: /v1/issues/019dda71-4897-7d62-853d-31f4899d9f8e

Runaway CPU investigation for python3.13: busy poll at unresolved offset in python3.13

possible duplicate

python3.13 is stuck in a likely busy poll loop: 100.00% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 1 thread(s) around 0x00007f091ce537d2 in ?? () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 2similarity: 99%

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

Last seen: 2026-07-02 03:18 UTC. Public page: /issues/019dc2a0-9ae7-7f42-8f59-415fe22abe51. Public JSON: /v1/issues/019dc2a0-9ae7-7f42-8f59-415fe22abe51

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

possible duplicate

python3.13 is stuck in a likely busy poll loop: 9.89% of sampled CPU passed through memset_orig, with repeated thread backtraces show 2 thread(s) around 0x00007fa228821ffe in ?? () from target:<path> and 1 thread(s) around 0x00007fa225d50890 in QuoteString(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, char const*) () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 1similarity: 99%

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

Last seen: 2026-07-04 05:55 UTC. Public page: /issues/019ede28-30fa-7e02-a28f-53fd67a6326a. Public JSON: /v1/issues/019ede28-30fa-7e02-a28f-53fd67a6326a

Runaway CPU investigation for python3.13: busy poll at unresolved offset in apt_pkg.cpython-313-x86_64-linux-gnu.so

possible duplicate

python3.13 is stuck in a likely busy poll loop: 15.28% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 2 thread(s) around 0x00007f35495474be in ?? () from target:<path> and 1 thread(s) around 0x000000000057151f in _PyEval_EvalFrameDefault ().

highpackage: python3.13-minimalsource: python3.13score: 106reports: 2successful triagesimilarity: 91%

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

Last seen: 2026-07-07 10:15 UTC. Public page: /issues/019dd98b-0e1d-76e3-9171-f0f72c689536. Public JSON: /v1/issues/019dd98b-0e1d-76e3-9171-f0f72c689536

Runaway CPU investigation for python3.13: dbus spin at unresolved offset in libc.so.6

possible duplicate

python3.13 is stuck in a likely dbus spin loop: 3.95% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 2 thread(s) around 0x00007f2de17b84be in ?? () from target:<path> and 1 thread(s) around 0x00007f2de17b84be in ?? () from target:<path>.

highpackage: python3.13-minimalsource: python3.13score: 106reports: 1similarity: 79%

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

Last seen: 2026-07-06 13:45 UTC. Public page: /issues/019f357c-d6d6-7f61-9f19-fde577e0ce21. Public JSON: /v1/issues/019f357c-d6d6-7f61-9f19-fde577e0ce21

Published attempts

No public attempts have been published for this issue yet.

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