Re: [PATCH v6 1/1] gpio: add sloppy logic analyzer using polling
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: 2021-12-22 12:58:31
Also in:
linux-renesas-soc, lkml
Subsystem:
gpio uapi, the rest · Maintainers:
Bartosz Golaszewski, Linus Torvalds
quoted
Yes, the search engines helped[1]. I run a minimal system, so when I mount cpusets, it will actually mount cgroups with a default mount option of "noprefix". But you likely run a rootfs with cgroups already, so it gets mounted directly without "noprefix". Then, when the logic analyzer tries to mount again, the implied default "noprefix" is discarded.Yeah, systemd on Debian has it mounted.
So, the proper solution is to use/mount 'cgroups2' instead of 'cpuset'. But this needs more thinking and testing and, thus, another revision. Dunno if I can make it this year, so I am probably going to miss the next merge window after all :( Geert, if you still want to test the PFC patch I sent, then this patch for the script should get you going:
diff --git a/tools/gpio/gpio-sloppy-logic-analyzer b/tools/gpio/gpio-sloppy-logic-analyzer
index eb2065fe6733..f1bfdd3568cf 100755
--- a/tools/gpio/gpio-sloppy-logic-analyzer
+++ b/tools/gpio/gpio-sloppy-logic-analyzer@@ -80,13 +80,13 @@ init_cpu() mount | grep -q $cpusetdir || mount -t cpuset cpuset $cpusetdir [ -d "$lacpusetdir" ] || mkdir "$lacpusetdir" - cur_cpu="$(cat "$lacpusetdir"/cpus)" + cur_cpu="$(cat "$lacpusetdir"/cpuset.cpus)" [ "$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 > "$lacpusetdir"/mems + echo "$isol_cpu" > "$lacpusetdir"/cpuset.cpus || fail "Could not isolate CPU$isol_cpu. Does it exist?" + echo 1 > "$lacpusetdir"/cpuset.cpu_exclusive + echo 0 > "$lacpusetdir"/cpuset.mems oldmask=$(cat /proc/irq/default_smp_affinity) newmask=$(printf "%x" $((0x$oldmask & ~(1 << isol_cpu))))
@@ -213,7 +213,7 @@ if [ -n "$triggerdat" ]; then printf "$trigger_bindat" > "$lasysfsdir"/trigger 2>/dev/null || fail "Trigger data '$triggerdat' rejected" fi -workcpu=$(cat "$lacpusetdir"/effective_cpus) +workcpu=$(cat "$lacpusetdir"/cpuset.effective_cpus) [ -n "$workcpu" ] || fail "No isolated CPU found" cpumask=$(printf '%x' $((1 << workcpu))) instance=${lasysfsdir##*/}
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