commit 318681d3e019e39354cc6c2155a7fd1bb8e8084d Author: Pavel Machek Date: Sat Sep 19 11:34:58 2020 +0200 ledtrig-cpu: Limit to 4 CPUs Some machines have thousands of CPUs... and trigger mechanisms was not really meant for thousands of triggers. I doubt anyone uses this trigger on many-CPU machine; but if they do, they'll need to do it properly. Signed-off-by: Pavel Machek diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c index 869976d1b734..b7e00b09b137 100644 --- a/drivers/leds/trigger/ledtrig-cpu.c +++ b/drivers/leds/trigger/ledtrig-cpu.c @@ -2,14 +2,18 @@ /* * ledtrig-cpu.c - LED trigger based on CPU activity * - * This LED trigger will be registered for each possible CPU and named as - * cpu0, cpu1, cpu2, cpu3, etc. + * This LED trigger will be registered for first four CPUs and named + * as cpu0, cpu1, cpu2, cpu3. There's additional trigger called cpu that + * is on when any CPU is active. + * + * If you want support for arbitrary number of CPUs, make it one trigger, + * with additional sysfs file selecting which CPU to watch. * * It can be bound to any LED just like other triggers using either a * board file or via sysfs interface. * * An API named ledtrig_cpu is exported for any user, who want to add CPU - * activity indication in their code + * activity indication in their code. * * Copyright 2011 Linus Walleij * Copyright 2011 - 2012 Bryan Wu @@ -145,6 +149,9 @@ static int __init ledtrig_cpu_init(void) for_each_possible_cpu(cpu) { struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu); + if (cpu > 4) + continue; + snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu); led_trigger_register_simple(trig->name, &trig->_trig); -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html