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authorPeter Zijlstra <peterz@infradead.org>2018-01-22 22:53:28 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-05 19:41:17 +0100
commite5d981df9a1d3f13dfff083ab0578daedbcd9e8a (patch)
tree91b388528b45cba3538aee53a5af6f9ed11f7c76 /kernel/sched
parent72e5a2bdf753f5ba82ea6bfb7706aabc9587d0cb (diff)
sched/core: Fix cpu.max vs. cpuhotplug deadlock
commit ce48c146495a1a50e48cdbfbfaba3e708be7c07c upstream Tejun reported the following cpu-hotplug lock (percpu-rwsem) read recursion: tg_set_cfs_bandwidth() get_online_cpus() cpus_read_lock() cfs_bandwidth_usage_inc() static_key_slow_inc() cpus_read_lock() Reported-by: Tejun Heo <tj@kernel.org> Tested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180122215328.GP3397@worktop Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/fair.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2d4d79420e36..7240bb4a4090 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4040,12 +4040,12 @@ static inline bool cfs_bandwidth_used(void)
void cfs_bandwidth_usage_inc(void)
{
- static_key_slow_inc(&__cfs_bandwidth_used);
+ static_key_slow_inc_cpuslocked(&__cfs_bandwidth_used);
}
void cfs_bandwidth_usage_dec(void)
{
- static_key_slow_dec(&__cfs_bandwidth_used);
+ static_key_slow_dec_cpuslocked(&__cfs_bandwidth_used);
}
#else /* HAVE_JUMP_LABEL */
static bool cfs_bandwidth_used(void)