diff options
| author | Clark Williams <williams@redhat.com> | 2011-07-30 21:55:53 -0500 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-10-29 18:20:18 +0100 |
| commit | 443a8674bc245a861732ad90e3fb39aaa71a857e (patch) | |
| tree | f6fb69d32480cb62e918f0052ea3a4c910be75d1 /kernel/ksysfs.c | |
| parent | 1c84b9b7b55a16c4a3788a101885eacf35625ddd (diff) | |
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>
Diffstat (limited to 'kernel/ksysfs.c')
| -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 46ba853656f6..9a23632b6294 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -140,6 +140,15 @@ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_CRASH_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) @@ -231,6 +240,9 @@ static struct attribute * kernel_attrs[] = { &rcu_expedited_attr.attr, &rcu_normal_attr.attr, #endif +#ifdef CONFIG_PREEMPT_RT_FULL + &realtime_attr.attr, +#endif NULL }; |