[Bug 279203] logger: Forking many logger executables at once renders machine unresponsive
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=279203 Michael Gmelin changed: What|Removed |Added Flags||mfc-stable13?, ||needs_errata? -- You are receiving this mail because: You are the assignee for the bug.
[Bug 279203] logger: Forking many logger executables at once renders machine unresponsive
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=279203 --- Comment #2 from Michael Gmelin --- Cherry-picking this commit fixes the issue for me: commit 7a70f17ac4bd64dc1a5020f963ba4380cf37b7e5 Author: Konstantin Belousov Date: Fri Jul 7 20:19:33 2023 +0300 killpg(): more carefully avoid LoR otherwise we could end up with the livelock. When pg_killsx trylock failed, ensure that we do wait for lock availability before retry. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week -- You are receiving this mail because: You are the assignee for the bug.
[Bug 279203] logger: Forking many logger executables at once renders machine unresponsive
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=279203
Michael Gmelin changed:
What|Removed |Added
CC||k...@freebsd.org
--- Comment #1 from Michael Gmelin ---
This only seems to affect 13.3 and 13-STABLE after
https://cgit.freebsd.org/src/commit/?h=stable/13=2b0cd3b552942c642a84f8e224b989c02d97125d
("killpg(2): close a race with fork(2), part1").
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[Bug 279203] logger: Forking many logger executables at once renders machine unresponsive
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=279203 Bug ID: 279203 Summary: logger: Forking many logger executables at once renders machine unresponsive Product: Base System Version: 13.3-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: bin Assignee: b...@freebsd.org Reporter: gre...@freebsd.org CC: r...@freebsd.org Forking logger many times like this: #!/bin/sh for id in $(jot 100); do logger -p local2.info -t pot "wledkjweldjwldjkwedj" & done sends the machine into some race condition, causing loads of 300-500. I can reproduce it on multicore machines (including within bhyve), not on single core. Load is mostly caused by system calls. When knowing pids, it's sometimes possible to recover the host by killing all logger processes (killall won't work though, as the machine is too loaded for that). I could not reproduce this on 13.2 (at least not as easily). When building logger without capsicum, this doesn't happen, but that could be a red herring. Happens on 13.3 as well as 13.3p2. This is causing quite some headache. We put logger under a lock to reduce concurrency, which made things better, but we still see the general situation (either other things call logger or, more likely, this is just a symptom of a bigger underlying issue). -- You are receiving this mail because: You are the assignee for the bug.
