From: Sascha Hauer <s.hauer@pengutronix.de>
To: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: barebox@lists.infradead.org
Subject: Re: [RFC PATCH 0/2] use gnuhash to speed up device/driver match
Date: Mon, 6 Mar 2017 09:11:09 +0100 [thread overview]
Message-ID: <20170306081109.d5dltjktxtgp5xtb@pengutronix.de> (raw)
In-Reply-To: <20170304071241.GG4120@mail.ovh.net>
On Sat, Mar 04, 2017 at 08:12:41AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> Hi,
>
> The following patch series use the gnu hash to speedup device/driver
> matching.
>
> String compare is slow so we will calculate at runtime a hash that we
> can compare quickly to speed up the match
>
> in a second step we could speed up this more by calculating the hash
> at compile time
On a i.MX53 quickstart board this patch reduces startup time from 115.9ms
to 115.4ms. On a i.MX35 board the startup time is reduced by 72us. I
don't think this is a valuable gain. Do you have any situation where you
really spend significant time in strcmp?
Sascha
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prev parent reply other threads:[~2017-03-06 8:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-04 7:12 Jean-Christophe PLAGNIOL-VILLARD
2017-03-04 7:14 ` [PATCH 1/2] driver: remove the const of struct platform_device_id *id_table Jean-Christophe PLAGNIOL-VILLARD
2017-03-04 7:14 ` [PATCH 2/2] driver: generate hash at runtime to speed up device/driver matching Jean-Christophe PLAGNIOL-VILLARD
2017-03-06 8:11 ` Sascha Hauer [this message]
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