Public issue detail

Runaway CPU investigation for postgres: socket churn at _dl_map_new_object

postgres is stuck in a likely socket churn loop: 3.49% of sampled CPU passed through _dl_map_new_object, with repeated thread backtraces show 1 thread(s) around 0x00007f912645c687 in __GI__IO_flush_all () from target:<path>.

highpackage: postgresql-18source: postgresql-18score: 106reports: 1

Last seen: 2026-10-17 07:40 UTC. Public JSON: /v1/issues/019f9db1-7511-7382-938c-68a2e3e906c8

Technical snapshot

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

Representative thread backtrace

  • Command: /usr/lib/postgresql/16/bin/postgres -D /tmp/postgis-pg16.1TZopz/data -F -h -p 32698 -k /tmp/postgis-pg16.1TZopz/socket -c fsync=off -c full_page_writes=off -c synchronous_commit=off
  • Why Fixer classified it this way: The trace is dominated by socket syscalls, which suggests the process is rapidly retrying or churning through network or IPC work.
  • Thread summary: thread backtraces show 1 thread(s) around 0x00007f912645c687 in __GI__IO_flush_all () from target:<path>
  • Contention signals: event-loop-wakeups, gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory. warning: Target and debugger are in different PID namespaces; thread lists and other data are likely unreliable. Connect to gdbserver inside the container. warning: Expected absolute pathname for libpthread in the inferior, but got target:<path> warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  • Repeated loop: lseek -> lseek -> lseek
  • Top syscalls: lseek x7305, pread64 x6076, read x5350, mmap x4667
  • Kernel: 7.1.8+deb14.1-amd64
  • Distribution: debian
0x00007f912645c687 in __GI__IO_flush_all () from target:<path>
0x00007f912645c6ad in __GI__IO_flush_all () from target:<path>
0x00007f91264dda6d in epoll_wait () from target:<path>
0x0000557094c71f5b in WaitEventSetWait ()
0x0000557094c0a745 in ?? ()
0x0000557094c0d47c in PostmasterMain ()
0x00005570949324ec 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 postgres: file not found retry at _dl_map_new_object

possible duplicate

postgres is stuck in a likely file not found retry loop: 1.58% of sampled CPU passed through _dl_map_new_object, with repeated thread backtraces show 1 thread(s) around 0x00007fb038f9c687 in __GI__IO_flush_all () from target:<path>.

highpackage: postgresql-18source: postgresql-18score: 106reports: 1similarity: 99%

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

Last seen: 2026-10-21 03:01 UTC. Public page: /issues/019f9e46-ed87-7693-a004-3c6b0b260a51. Public JSON: /v1/issues/019f9e46-ed87-7693-a004-3c6b0b260a51

Runaway CPU investigation for postgres: socket churn at next_uptodate_folio

possible duplicate

postgres is stuck in a likely socket churn loop: 1.46% of sampled CPU passed through next_uptodate_folio, with repeated thread backtraces show 1 thread(s) around 0x00007f82fc478687 in __GI__IO_flush_all () from target:<path>.

highpackage: postgresql-18source: linuxscore: 106reports: 1similarity: 99%

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

Last seen: 2026-10-16 07:15 UTC. Public page: /issues/019f777c-b6c6-73c1-9b2a-9e06e91c6ca9. Public JSON: /v1/issues/019f777c-b6c6-73c1-9b2a-9e06e91c6ca9

Runaway CPU investigation for postgres: futex lock contention at _dl_map_new_object

possible duplicate

postgres is stuck in a likely futex lock contention loop: 2.64% of sampled CPU passed through _dl_map_new_object, with repeated thread backtraces show 1 thread(s) around 0x00007fa0aa49bca2 in __futex_abstimed_wait_common (futex_word=..., expected=..., clockid=..., abstime=..., private=..., cancel=...) at .<path>:103.

highpackage: postgresql-18source: postgresql-18score: 106reports: 1similarity: 97%

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

Last seen: 2026-10-13 06:02 UTC. Public page: /issues/01a0faf7-676a-70a3-9cf2-63d0f9d56063. Public JSON: /v1/issues/01a0faf7-676a-70a3-9cf2-63d0f9d56063

Runaway CPU investigation for postgres: socket churn at unresolved offset in postgres

possible duplicate

postgres is stuck in a likely socket churn loop: 1.90% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 1 thread(s) around 0x00007f1303299687 in __GI__IO_flush_all () from target:<path>.

highscore: 106reports: 1similarity: 97%

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

Last seen: 2026-10-19 03:26 UTC. Public page: /issues/019f7962-c828-7c50-8189-f439a8864601. Public JSON: /v1/issues/019f7962-c828-7c50-8189-f439a8864601

Runaway CPU investigation for postgres: timer churn at start_dl_timer

possible duplicate

postgres is stuck in a likely timer churn loop: 100.00% of sampled CPU passed through start_dl_timer, with repeated thread backtraces show 1 thread(s) around 0x00007f322d29a7d2 in ?? () from target:<path>.

highpackage: postgresql-18source: postgresql-18score: 106reports: 2similarity: 96%

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

Last seen: 2026-10-22 20:40 UTC. Public page: /issues/019e5d7e-79c8-70a3-bcbd-6d4643b9285a. Public JSON: /v1/issues/019e5d7e-79c8-70a3-bcbd-6d4643b9285a

Runaway CPU investigation for postgres: socket churn at hash_search_with_hash_value

possible duplicate

postgres is stuck in a likely socket churn loop: 3.62% of sampled CPU passed through hash_search_with_hash_value, with repeated thread backtraces show 1 thread(s) around 0x00007f1f311da687 in __GI__IO_flush_all () from target:<path>.

highpackage: postgresql-14source: postgresql-14score: 106reports: 1similarity: 91%

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

Last seen: 2026-10-21 04:00 UTC. Public page: /issues/019d8b2f-863a-7af0-92eb-7ce77dd04988. Public JSON: /v1/issues/019d8b2f-863a-7af0-92eb-7ce77dd04988

Published attempts

No public attempts have been published for this issue yet.

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