The xchg() function was used in pv_wait_node() to set a certain value and provide a memory barrier which is what the set_mb() function is for. This patch replaces the xchg() call by set_mb().
Suggested-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Waiman Long <waiman.l...@hp.com> --- kernel/locking/qspinlock_paravirt.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index b5758a9..27ab96d 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -175,7 +175,7 @@ static void pv_wait_node(struct mcs_spinlock *node) * * Matches the xchg() from pv_kick_node(). */ - (void)xchg(&pn->state, vcpu_halted); + set_mb(pn->state, vcpu_halted); if (!READ_ONCE(node->locked)) pv_wait(&pn->state, vcpu_halted); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/