diff options
| author | Clark Williams <williams@redhat.com> | 2011-07-30 21:55:53 -0500 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2019-12-17 22:00:31 +0100 |
| commit | 0ad021ba6e573099913d786df7ef6be8b53014fd (patch) | |
| tree | ad3bb3a66c83ee6d4c20eea031764e123a0fd142 | |
| parent | 00857b80bfe7507e626ee33ac0e60eca8fcd71ae (diff) | |
| download | linux-rt-0ad021ba6e573099913d786df7ef6be8b53014fd.tar.gz | |
sysfs: Add /sys/kernel/realtime entry
Add a /sys/kernel entry to indicate that the kernel is a
realtime kernel.
Clark says that he needs this for udev rules, udev needs to evaluate
if its a PREEMPT_RT kernel a few thousand times and parsing uname
output is too slow or so.
Are there better solutions? Should it exist and return 0 on !-rt?
Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
| -rw-r--r-- | kernel/ksysfs.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 35859da8bd4f..dfff31ed644a 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -138,6 +138,15 @@ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_CRASH_CORE */ +#if defined(CONFIG_PREEMPT_RT) +static ssize_t realtime_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", 1); +} +KERNEL_ATTR_RO(realtime); +#endif + /* whether file capabilities are enabled */ static ssize_t fscaps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) @@ -229,6 +238,9 @@ static struct attribute * kernel_attrs[] = { &rcu_expedited_attr.attr, &rcu_normal_attr.attr, #endif +#ifdef CONFIG_PREEMPT_RT + &realtime_attr.attr, +#endif NULL }; |