Re: [PATCH tip/core/rcu 01/11] rcu: Expedite grace periods duringsuspend/resume

From: Josh Triplett
Date: Sat Aug 17 2013 - 23:17:32 EST


On Sat, Aug 17, 2013 at 06:37:46PM -0700, Paul E. McKenney wrote:
> From: Borislav Petkov <bp@xxxxxxxxx>
>
> CONFIG_RCU_FAST_NO_HZ can increase grace-period durations by up to
> a factor of four, which can result in long suspend and resume times.
> Thus, this commit temporarily switches to expedited grace periods when
> suspending the box and return to normal settings when resuming.
>
> [ paulmck: This also papers over an audio/irq bug, but hopefully that will
> be fixed soon. ]
>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

This patch still seems like a hack, and there *ought* to be a better
general solution to avoid excessive grace-period latency. Nonetheless,
in the absence of such a solution,
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
--
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/