diff options
Diffstat (limited to 'features/rt/sysfs-Add-sys-kernel-realtime-entry.patch')
| -rw-r--r-- | features/rt/sysfs-Add-sys-kernel-realtime-entry.patch | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/features/rt/sysfs-Add-sys-kernel-realtime-entry.patch b/features/rt/sysfs-Add-sys-kernel-realtime-entry.patch new file mode 100644 index 00000000..a70552cd --- /dev/null +++ b/features/rt/sysfs-Add-sys-kernel-realtime-entry.patch @@ -0,0 +1,53 @@ +From 0467137e4e4d875cc0711eaefbd0da8800274d86 Mon Sep 17 00:00:00 2001 +From: Clark Williams <williams@redhat.com> +Date: Sat, 30 Jul 2011 21:55:53 -0500 +Subject: [PATCH 190/191] 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> +--- + kernel/ksysfs.c | 12 ++++++++++++ + 1 file changed, 12 insertions(+) + +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) +@@ -228,6 +237,9 @@ static struct attribute * kernel_attrs[] = { + #ifndef CONFIG_TINY_RCU + &rcu_expedited_attr.attr, + &rcu_normal_attr.attr, ++#endif ++#ifdef CONFIG_PREEMPT_RT ++ &realtime_attr.attr, + #endif + NULL + }; +-- +2.19.1 + |