diff options
author | Antti P Miettinen <ananaza@iki.fi> | 2012-10-05 10:59:15 +0400 |
---|---|---|
committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-10-24 01:54:08 +0400 |
commit | 3705b88db0d7cc4a097c32d9e554054103d3f807 (patch) | |
tree | f3baf8c94363506964c9f944496267f74cdee47c /kernel/ksysfs.c | |
parent | ba49df4767d4fa5bbd2af3a51709fb81f94264ec (diff) |
rcu: Add a module parameter to force use of expedited RCU primitives
There have been some embedded applications that would benefit from
use of expedited grace-period primitives. In some ways, this is
similar to synchronize_net() doing either a normal or an expedited
grace period depending on lock state, but with control outside of
the kernel.
This commit therefore adds rcu_expedited boot and sysfs parameters
that cause the kernel to substitute expedited primitives for the
normal grace-period primitives.
[ paulmck: Add trace/event/rcu.h to kernel/srcu.c to avoid build error.
Get rid of infinite loop through contention path.]
Signed-off-by: Antti P Miettinen <amiettinen@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/ksysfs.c')
-rw-r--r-- | kernel/ksysfs.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 4e316e1acf58..8715a798aa7c 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -141,6 +141,23 @@ static ssize_t fscaps_show(struct kobject *kobj, } KERNEL_ATTR_RO(fscaps); +int rcu_expedited; +static ssize_t rcu_expedited_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", rcu_expedited); +} +static ssize_t rcu_expedited_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + if (kstrtoint(buf, 0, &rcu_expedited)) + return -EINVAL; + + return count; +} +KERNEL_ATTR_RW(rcu_expedited); + /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ @@ -182,6 +199,7 @@ static struct attribute * kernel_attrs[] = { &kexec_crash_size_attr.attr, &vmcoreinfo_attr.attr, #endif + &rcu_expedited_attr.attr, NULL }; |