Passing invalid perf arguments

[twirrim]

I'm trying to run repro-mysql-EEVDF-regression, and I'm running into a slight issue.
To try to be as close to your report, I'm running this on Ubuntu 22.04

$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.5 LTS"

The version of perf that gets created against a 6.5 kernel doesn't support the --output argument that you're relying on as part of your test

$ which perf
/usr/local/bin/perf
$ uname -r
6.5.0-2dde18cd1d8f
$ perf --version
perf version 6.5.g2dde18cd1d8f
$ sudo perf sched stats record --help

 Usage: perf sched [<options>] {record|latency|map|replay|script|timehist}

    -D, --dump-raw-trace  dump raw trace in ASCII
    -f, --force           don't complain, do it
    -i, --input <file>    input file name
    -v, --verbose         be more verbose (show symbol address, etc)

This causes the test to hang on the SUT as the expected file isn't created:

[20250520.201633] [DEBUG] Running command: sudo perf sched stats record --output=perf-k6.5.0-default.data -- sleep 600
[20250520.201633] [WARN]                        
[20250520.201633] [WARN] Usage: perf sched [<options>] {record|latency|map|replay|script|timehist}
[20250520.201633] [WARN]                                                                                               
[20250520.201633] [WARN] -D, --dump-raw-trace  dump raw trace in ASCII            
[20250520.201633] [WARN] -f, --force           don't complain, do it               
[20250520.201633] [WARN] -i, --input <file>    input file name            
[20250520.201633] [WARN] -v, --verbose         be more verbose (show symbol address, etc)
[20250520.201633] [WARN]                 
[20250520.201633] [ERROR] Command returned 129       
[20250520.201633] [DEBUG] Running command: sudo bash -c 'echo 0 >/proc/sys/kernel/sched_schedstats'
[20250520.201633] [INFO] Command returned 0
[20250520.201633] [WARN] chown: cannot access 'perf-k6.5.0-default.data': No such file or directory
[20250520.201633] [WARN]                                                                                               
[20250520.201633] [DEBUG] Running command: sed -n "/CPU 0/q;p" "perf-${label}.report"
[20250520.201633] [WARN] Usage: perf sched [<options>] {record|latency|map|replay|script|timehist}
[20250520.201633] [WARN]                                                                                               
[20250520.201633] [WARN] -D, --dump-raw-trace  dump raw trace in ASCII
[20250520.201633] [INFO] Command returned 0                                                                            
[20250520.201633] [WARN] -f, --force           don't complain, do it
[20250520.201633] [WARN] -i, --input <file>    input file name
[20250520.201633] [WARN] -v, --verbose         be more verbose (show symbol address, etc)
[20250520.201633] [WARN]                                                                                               

[CristianPrundeanu]

It's not the --output argument that is the issue. It looks like perf failed to compile for kernel 6.5, which causes it to be unaware of the new sched stats command.

This is what the help of a "good" perf looks like (notice the "stats" keyword mentioned on the Usage line):

$ perf sched

 Usage: perf sched [<options>] {record|latency|map|replay|script|timehist|stats}

    -D, --dump-raw-trace  dump raw trace in ASCII
    -f, --force           don't complain, do it
    -i, --input <file>    input file name
    -v, --verbose         be more verbose (show symbol address, etc)

Either way, the SUT should not hang. The test is expected to complete all other tasks, since perf is run in parallel with the workload. The LDG will still output a score, but the perf-k6.5.0.report file on the SUT will be empty.

Will try to reproduce the build failure.

[divya5623]

Hi, I’d like to work on this issue. I’ll investigate why the perf build for kernel 6.5 is missing the sched stats command and also look into preventing the test from hanging when perf fails. I’ll reproduce the issue locally and submit a PR with the fix.