On Fri, 2026-07-10 at 01:08 +0800, Wen Yang wrote:
> > load() { # returns true if there was a reaction
> > - local lines_before num
> > + local lines_before num load_pid ret
> > num=$((($(nproc) + 1) / 2))
> > lines_before=$(dmesg | wc -l)
> > - stress-ng --cpu-sched "$num" --timer "$num" -t 5 -q
> > - dmesg | tail -n $((lines_before + 1)) | grep -q "rv: monitor wwnr
> > does not allow event"
> > + stress-ng --cpu-sched "$num" --timer "$num" -t 5 -q &
> > + load_pid=$!
> > + timeout 5 dmesg -w | tail -n +$((lines_before + 1)) | grep -m 1 -q
> > "rv: monitor wwnr does not allow event"
>
>
> Minor nit: could we add a small delay (e.g., sleep 0.1) before dmesg?
I don't get what the benefit would be.
The intent of that line is to run a continuous dmesg (-w) for up to 5s (timeout)
but stopping if an occurrence is found (grep -m 1 would close the pipe).
Do you see a case in which this wouldn't happen?
>
> Reviewed-by: Wen Yang <[email protected]>
>
> > + ret=$?
> > + kill "$load_pid"
> > + wait "$load_pid"
> > + return $ret
> > }
> >
> > echo 1 > monitors/wwnr/enable
> > echo printk > monitors/wwnr/reactors
> >
> > -load
> > -
> > echo 0 > monitoring_on
> > ! load || false
> > echo 1 > monitoring_on
> >
> > -load
> > -
> > echo 0 > reacting_on
> > ! load || false
> > echo 1 > reacting_on
> >
> > +load
> > +
> > echo nop > monitors/wwnr/reactors
> > echo 0 > monitors/wwnr/enable
