Re: [PATCH v6 1/1] gpio: add sloppy logic analyzer using polling

From: Geert Uytterhoeven
Date: Mon Dec 20 2021 - 15:02:01 EST


On Mon, Dec 20, 2021 at 3:12 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
On Mon, Dec 20, 2021 at 10:07 AM Wolfram Sang
> <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> > + [ -d "$lacpusetdir" ] || mkdir "$lacpusetdir"
> > +
> > + cur_cpu="$(cat "$lacpusetdir"/cpus)"
>
> cat: /dev/cpuset/gpio-sloppy-logic-analyzer/cpus: No such file or directory
>
> I do have a "cpuset.cpus" file.
>
> > + [ "$cur_cpu" = "$isol_cpu" ] && return
> > + [ -z "$cur_cpu" ] || fail "CPU$isol_cpu requested but CPU$cur_cpu already isolated"
> > +
> > + echo "$isol_cpu" > "$lacpusetdir"/cpus || fail "Could not isolate CPU$isol_cpu. Does it exist?"
> > + echo 1 > "$lacpusetdir"/cpu_exclusive
> > + echo 0 > "$lacpusetdir"/mems
>
> No complaint, although the real files have a "cpuset."-prefix again.
>
> [...]
>
> > +workcpu=$(cat "$lacpusetdir"/effective_cpus)
>
> cat: /dev/cpuset/gpio-sloppy-logic-analyzer/effective_cpus: No such
> file or directory
>
> I do have a "cpuset.effective_cpus" file.
>
> > +[ -n "$workcpu" ] || fail "No isolated CPU found"
> > +cpumask=$(printf '%x' $((1 << workcpu)))
> > +instance=${lasysfsdir##*/}
> > +echo "Setting up '$instance': $numsamples samples at ${samplefreq}Hz with ${triggerdat:-no} trigger using CPU$workcpu"
> > +do_capture "$cpumask" &
>
> Anyone with a clue? Thanks!

Documentation/admin-guide/cgroup-v1/cpusets.rst also has the prefixes,
so I'm wondering if you have some "legacy compatibility" config option
enabled?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds