Re: [GIT PULL] scheduler fixes

From: Peter Zijlstra
Date: Tue Oct 01 2019 - 03:19:30 EST


On Mon, Sep 30, 2019 at 04:45:49PM -0700, John Stultz wrote:
> Reverting the following patches:

> "sched/membarrier: Fix p->mm->membarrier_state racy load"

ARGH, I fudged it... please try:


diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index a39bed2c784f..168479a7d61b 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -174,7 +174,6 @@ static int membarrier_private_expedited(int flags)
*/
if (cpu == raw_smp_processor_id())
continue;
- rcu_read_lock();
p = rcu_dereference(cpu_rq(cpu)->curr);
if (p && p->mm == mm)
__cpumask_set_cpu(cpu, tmpmask);