mail archive of the barebox mailing list
 help / color / mirror / Atom feed
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

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

      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]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170306081109.d5dltjktxtgp5xtb@pengutronix.de \
    --to=s.hauer@pengutronix.de \
    --cc=barebox@lists.infradead.org \
    --cc=plagnioj@jcrosoft.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox