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| author |   Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2020-10-20 09:47:14 -0400 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2020-10-29 11:00:31 +0100 |
| commit | 618758ed3a4f7d790414d020b362111748ebbf9f (patch) | |
| tree | 9357b04f04a5ef25a162bed531eedce691339280 /kernel/sched/idle.c | |
| parent | sched: fix exit_mm vs membarrier (v4) (diff) | |
| download | linux-dev-618758ed3a4f7d790414d020b362111748ebbf9f.tar.xz linux-dev-618758ed3a4f7d790414d020b362111748ebbf9f.zip | |
sched: membarrier: cover kthread_use_mm (v4)
Add comments and memory barrier to kthread_use_mm and kthread_unuse_mm
to allow the effect of membarrier(2) to apply to kthreads accessing
user-space memory as well.
Given that no prior kthread use this guarantee and that it only affects
kthreads, adding this guarantee does not affect user-space ABI.
Refine the check in membarrier_global_expedited to exclude runqueues
running the idle thread rather than all kthreads from the IPI cpumask.
Now that membarrier_global_expedited can IPI kthreads, the scheduler
also needs to update the runqueue's membarrier_state when entering lazy
TLB state.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201020134715.13909-3-mathieu.desnoyers@efficios.com
Diffstat (limited to 'kernel/sched/idle.c')
| -rw-r--r-- | kernel/sched/idle.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 24d0ee26377d..846743e39b3c 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -338,6 +338,7 @@ void play_idle_precise(u64 duration_ns, u64 latency_ns) WARN_ON_ONCE(!(current->flags & PF_KTHREAD)); WARN_ON_ONCE(!(current->flags & PF_NO_SETAFFINITY)); WARN_ON_ONCE(!duration_ns); + WARN_ON_ONCE(current->mm); rcu_sleep_check(); preempt_disable(); |