Re: [PATCH 5/7] locking/pvqspinlock: Add pending bit support

From: Peter Zijlstra
Date: Sun Jul 12 2015 - 04:22:22 EST


On Sat, Jul 11, 2015 at 04:36:56PM -0400, Waiman Long wrote:
> Like the native qspinlock, using the pending bit when it is lightly
> loaded to acquire the lock is faster than going through the PV queuing
> process which is even slower than the native queuing process. It also
> avoids loading two additional cachelines (the MCS and PV nodes).
>
> This patch adds the pending bit support for PV qspinlock. The
> pending bit code has a smaller spin threshold. It will default back
> to the queuing method if it cannot acquired the lock within a certain
> time limit.

-ENONUMBERS
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/