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From: Christoph Lameter <cl@linux.com>
To: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: akpm@linuxfoundation.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, penberg@kernel.org, iamjoonsoo@lge.com
Subject: Re: [PATCH 2/3] slub: Support for array operations
Date: Wed, 11 Feb 2015 20:46:53 -0600 (CST)	[thread overview]
Message-ID: <alpine.DEB.2.11.1502112045540.21460@gentwo.org> (raw)
In-Reply-To: <20150212131649.59b70f71@redhat.com>

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.

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  reply	other threads:[~2015-02-12  2:46 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-10 19:48 [PATCH 0/3] Slab allocator array operations V2 Christoph Lameter
2015-02-10 19:48 ` [PATCH 1/3] Slab infrastructure for array operations Christoph Lameter
2015-02-10 22:43   ` Jesper Dangaard Brouer
2015-02-10 23:58   ` David Rientjes
2015-02-11 18:47     ` Christoph Lameter
2015-02-11 20:18       ` David Rientjes
2015-02-11 22:04         ` Christoph Lameter
2015-02-12  0:35           ` David Rientjes
2015-02-13  2:35         ` Joonsoo Kim
2015-02-13 15:47           ` Christoph Lameter
2015-02-13 21:20             ` David Rientjes
2015-02-17  5:15             ` Joonsoo Kim
2015-02-17 16:03               ` Christoph Lameter
2015-02-17 21:32                 ` Jesper Dangaard Brouer
2015-02-18 23:02                   ` Christoph Lameter
2015-02-10 19:48 ` [PATCH 2/3] slub: Support " Christoph Lameter
2015-02-11  4:48   ` Jesper Dangaard Brouer
2015-02-11 19:07     ` Christoph Lameter
2015-02-11 21:43       ` Jesper Dangaard Brouer
2015-02-11 22:06         ` Christoph Lameter
2015-02-12  0:16           ` Jesper Dangaard Brouer
2015-02-12  2:46             ` Christoph Lameter [this message]
2015-02-13  2:45   ` Joonsoo Kim
2015-02-13 15:49     ` Christoph Lameter
2015-02-17  5:26       ` Joonsoo Kim
2015-02-10 19:48 ` [PATCH 3/3] Array alloc test code Christoph Lameter

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