Re: [PATCH 2/3] slub: Support for array operations

From: Christoph Lameter
Date: Wed Feb 11 2015 - 21:47:27 EST


On Thu, 12 Feb 2015, Jesper Dangaard Brouer wrote:

> Measured on my laptop CPU i7-2620M CPU @ 2.70GHz:
>
> * 12.775 ns - "clean" spin_lock_unlock
> * 21.099 ns - irqsave variant spinlock
> * 22.808 ns - "manual" irqsave before spin_lock
> * 14.618 ns - "manual" local_irq_disable + spin_lock
>
> Reproducible via my github repo:
> https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/time_bench_sample.c
>
> The clean spin_lock_unlock is 8.324 ns faster than irqsave variant.
> The irqsave variant is actually faster than expected, as the measurement
> of an isolated local_irq_save_restore were 13.256 ns.

I am using spin_lock_irq() in the current version on my system. If the
performance of that is a problem then please optimize that function.
--
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/