summaryrefslogtreecommitdiffstats
path: root/kernel/cpu.c
diff options
context:
space:
mode:
authorWaiman Long <longman@redhat.com>2018-07-24 14:26:04 -0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-07-26 10:37:36 +0200
commit6f4ceee9305dc3fe74099159b460f4b56b506f1d (patch)
tree167a0733c55bae01d2ccb6ac7c0148144d0b3589 /kernel/cpu.c
parent601b218568a107370086dc5c7a1b283f8d463268 (diff)
downloadlinux-6f4ceee9305dc3fe74099159b460f4b56b506f1d.tar.bz2
cpu/hotplug: Add a cpus_read_trylock() function
There are use cases where it can be useful to have a cpus_read_trylock() function to work around circular lock dependency problem involving the cpu_hotplug_lock. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 0db8938fbb23..307486baa477 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -290,6 +290,12 @@ void cpus_read_lock(void)
}
EXPORT_SYMBOL_GPL(cpus_read_lock);
+int cpus_read_trylock(void)
+{
+ return percpu_down_read_trylock(&cpu_hotplug_lock);
+}
+EXPORT_SYMBOL_GPL(cpus_read_trylock);
+
void cpus_read_unlock(void)
{
percpu_up_read(&cpu_hotplug_lock);