Re: [PATCH] padata: use smp_mb in padata_reorder to avoid orphaned padata jobs

From: Daniel Jordan
Date: Tue Jul 16 2019 - 11:44:41 EST


On 7/16/19 11:01 AM, Herbert Xu wrote:
On Tue, Jul 16, 2019 at 02:53:09PM +0200, Andrea Parri wrote:

P1(atomic_t *reorder_objects, spinlock_t *pd_lock, spinlock_t *reorder_lock)
{
int r1;

spin_lock(reorder_lock);
atomic_inc(reorder_objects);
spin_unlock(reorder_lock);
//smp_mb();
r1 = spin_trylock(pd_lock);
}

Yes we need a matching mb on the other side. However, we can
get away with using smp_mb__after_atomic thanks to the atomic_inc
above.

Daniel, can you please respin the patch with the matching smp_mb?

Sure, Herbert, will do.

Thanks,
Daniel