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| author | Clark Williams <williams@redhat.com> | 2011-07-30 21:55:53 -0500 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-02-13 00:36:27 +0100 |
| commit | c129f89a0e4bce7198f296e3472acc045f082370 (patch) | |
| tree | e3e1a2706387d7c81b8f7bf94f47900eb44f7f8e | |
| parent | 75028177e2b59cbb59f75a5838d23b44ca495091 (diff) | |
| download | rt-linux-c129f89a0e4bce7198f296e3472acc045f082370.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 e83b264640615..c0e08d1cf33ed 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -136,6 +136,15 @@ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_KEXEC_CORE */ +#if defined(CONFIG_PREEMPT_RT_FULL) +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) @@ -203,6 +212,9 @@ static struct attribute * kernel_attrs[] = { &vmcoreinfo_attr.attr, #endif &rcu_expedited_attr.attr, +#ifdef CONFIG_PREEMPT_RT_FULL + &realtime_attr.attr, +#endif NULL }; |