run-stp-tests.sh test hangs with large open file limit number

[glaubitz]

On Debian, systemd is configured to enable a large open file limit number of 1073741816.

This causes the run-stp-tests.sh script to timeout:

Running command tests...
Performing 5.1-lpadmin.sh: FAIL
Performing 5.2-lpc.sh: PASS
Performing 5.3-lpq.sh: FAIL
Performing 5.4-lpstat.sh: FAIL
Performing 5.5-lp.sh: FAIL
Performing 5.6-lpr.sh: FAIL
Performing 5.7-lprm.sh: FAIL
Performing 5.8-cancel.sh: FAIL
Performing 5.9-lpinfo.sh: FAIL
Performing restart test: ./run-stp-tests.sh: 811: kill: No such process

E: Build killed with signal TERM after 600 minutes of inactivity

This has been reported in Debian as: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1073046

[zdohnal]

I was able to to reproduce the issue by setting ulimit for -n to the Debian default number - I'm looking into it further.

[michaelrsweet]

We used to have an issue with the cupsd startup attempting to close all files, but we added a limit of 1024 files to close on startup. But since this is for the restart test I'm not sure what might be happening...

[zdohnal]

I haven't confirmed it with my gdb run, but IMO what the guy from Debian saw is correct - calloc() returns NULL, because we try to allocate too much memory, because we take size from MaxFDs, which is taken from system max number of files.

The fix might be simple (probably limit MaxFDs to some sane number), but unfortunately I'm occupied with stuff around Centos Stream 10 atm... I hope I look into it before my vacation.

[michaelrsweet]

I've updated the upper limit for MaxFDs to 65535 since more than that doesn't really matter (can't have more than 65535 active TCP connections from a single system - protocol limitation):

[master a66f419d4] Limit the maximum number of file descriptors to 64k-1 (Issue #989)

[2.4.x beb84401c] Limit the maximum number of file descriptors to 64k-1 (Issue #989)

Please let me know it this solves your issues...