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| author |   Pavel Machek <pavel@ucw.cz> | 2020-09-19 11:34:58 +0200 |
|---|---|---|
| committer | Pavel Machek <pavel@ucw.cz> | 2020-09-30 19:15:40 +0200 |
| commit | abcc131292aa8c7de2c5f0ed76a717436c21de63 (patch) | |
| tree | 80c17af851c1332247630cd7f323dfaef04dcc83 /drivers/leds | |
| parent | leds: TODO: Add documentation about possible subsystem improvements (diff) | |
| download | linux-dev-abcc131292aa8c7de2c5f0ed76a717436c21de63.tar.xz linux-dev-abcc131292aa8c7de2c5f0ed76a717436c21de63.zip | |
ledtrig-cpu: Limit to 8 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 <pavel@ucw.cz>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/trigger/ledtrig-cpu.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c index 869976d1b734..fca62d503590 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 8 CPUs and named + * as cpu0..cpu7. 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 <linus.walleij@linaro.org> * Copyright 2011 - 2012 Bryan Wu <bryan.wu@canonical.com> @@ -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 >= 8) + continue; + snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu); led_trigger_register_simple(trig->name, &trig->_trig); |