Public issue detail

Runaway CPU investigation for perl: busy poll at do_select

perl is stuck in a likely busy poll loop: 100.00% of sampled CPU passed through do_select, with repeated thread backtraces show 1 thread(s) around 0x00007f4392f987d2 in ?? () from target:<path>.

highpackage: perl-basesource: perlscore: 106reports: 1

Last seen: 2026-06-28 21:10 UTC. Public JSON: /v1/issues/019db582-c9cc-78d0-8104-f1490ac23dc9

Technical snapshot

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

Representative thread backtrace

  • Command: /usr/bin/perl -wT /usr/sbin/munin-node --foreground
  • 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 1 thread(s) around 0x00007f4392f987d2 in ?? () from target:<path>
  • Contention signals: gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory.
  • Repeated loop: pselect6 -> pselect6 -> pselect6
  • Top syscalls: pselect6 x3
  • Package: perl-base 5.40.1-7+b1
  • Kernel: 6.17.10+deb14-amd64
  • Distribution: debian
0x00007f4392f987d2 in ?? () from target:<path>
0x00007f4392f987ed in ?? () from target:<path>
0x00007f43930186cf in select () from target:<path>
0x0000559bb8f34ee4 in ?? ()
0x0000559bb8f96496 in Perl_runops_standard ()
0x0000559bb8e7cb85 in perl_run ()
0x0000559bb8e4f5ae in main ()

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 perl: busy poll at Perl_runops_standard

possible duplicate

perl is stuck in a likely busy poll loop: 100.00% of sampled CPU passed through Perl_runops_standard, with repeated pselect6 x4.

highpackage: perl-basesource: perlscore: 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: 2026-07-10 03:06 UTC. Public page: /issues/019d4017-20f8-7752-9734-0bcd71623118. Public JSON: /v1/issues/019d4017-20f8-7752-9734-0bcd71623118

Runaway CPU investigation for perl: busy poll at native_sched_clock

possible duplicate

perl is stuck in a likely busy poll loop: 100.00% of sampled CPU passed through native_sched_clock, with repeated thread backtraces show 1 thread(s) around 0x00007f5e185decb2 in ?? () from target:<path>.

highpackage: perl-basesource: perlscore: 106reports: 1similarity: 99%

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

Last seen: 2026-07-07 21:30 UTC. Public page: /issues/019f343d-8e8c-7c63-9a54-a9a5e87db750. Public JSON: /v1/issues/019f343d-8e8c-7c63-9a54-a9a5e87db750

Runaway CPU investigation for perl: busy poll at update_sd_lb_stats.constprop.0

possible duplicate

perl is stuck in a likely busy poll loop: 100.00% of sampled CPU passed through update_sd_lb_stats.constprop.0, with repeated thread backtraces show 1 thread(s) around 0x00007f9a01ce47d2 in ?? () from target:<path>.

highpackage: perl-basesource: perlscore: 106reports: 1similarity: 99%

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

Last seen: 2026-07-04 21:40 UTC. Public page: /issues/019f2bc3-ddea-71c0-a8a5-ad543673ae26. Public JSON: /v1/issues/019f2bc3-ddea-71c0-a8a5-ad543673ae26

Runaway CPU investigation for perl: busy poll at Perl_hv_iternext_flags

possible duplicate

perl is stuck in a likely busy poll loop: 100.00% of sampled CPU passed through Perl_hv_iternext_flags, with repeated thread backtraces show 1 thread(s) around 0x00007f421c5d77d2 in ?? () from target:<path>.

highpackage: perl-basesource: perlscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same package, same source package, same subsystem, same target, same wait site, very similar public summary

Last seen: 2026-07-04 05:55 UTC. Public page: /issues/019f1022-894c-7852-a604-32786bebab0d. Public JSON: /v1/issues/019f1022-894c-7852-a604-32786bebab0d

Runaway CPU investigation for rsync: busy poll at clear_page_erms

possible duplicate

rsync is stuck in a likely busy poll loop: 24.28% of sampled CPU passed through clear_page_erms, with repeated thread backtraces show 1 thread(s) around 0x00007f1f5169a7d2 in ?? () from target:<path>.

highpackage: rsyncsource: rsyncscore: 106reports: 2similarity: 79%

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

Last seen: 2026-07-02 23:40 UTC. Public page: /issues/019e1a88-12a2-79f0-8a00-0794e663896a. Public JSON: /v1/issues/019e1a88-12a2-79f0-8a00-0794e663896a

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: 78%

Why this looks related: same classification, same subsystem, 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

Published attempts

No public attempts have been published for this issue yet.

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