From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: MMC quirks relating to performance/lifetime.
Date: Fri, 11 Feb 2011 16:25:13 +0100 [thread overview]
Message-ID: <201102111625.14226.arnd@arndb.de> (raw)
In-Reply-To: <AANLkTimS-1CxkSHDChqX1K8bt-89T=8SDoSdmKeZ4PXG@mail.gmail.com>
On Friday 11 February 2011, Lei Wen wrote:
> > Several orders of magnitude. It is very easy to get a card that can write
> > 12 MB/s into a case where it writes no more than 30 KB/s, doing only
> > things that happen frequently with ext3.
> >
>
> Maybe we could get that case into mmc_test code, so that we could track
> that in latter whether it already be fixed or not? Or in other word, to prove
> the firmware in sd card is stupid or not. :)
There are many kinds of stupid, and a lot of cards are. I've actually had
excellent success with simply measuring from user space, which is
much easier than in mmc_test.
Unfortunately, you have to write to the card to do that, which may destroy
the data even if you write the same data that is already on it.
See
https://wiki.linaro.org/WorkingGroups/KernelConsolidation/Projects/FlashCardSurvey
for most of my results. I'm about to write up a better paper with all the
measurements, and will make my tools available soon.
Arnd
next prev parent reply other threads:[~2011-02-11 15:25 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-08 21:22 MMC quirks relating to performance/lifetime Andrei Warkentin
2011-02-08 21:38 ` Wolfram Sang
2011-02-08 21:38 ` Wolfram Sang
2011-02-08 22:42 ` Russell King - ARM Linux
2011-02-09 8:37 ` Linus Walleij
2011-02-09 8:37 ` Linus Walleij
2011-02-09 9:13 ` Arnd Bergmann
2011-02-09 9:13 ` Arnd Bergmann
2011-02-11 22:33 ` Andrei Warkentin
2011-02-11 22:33 ` Andrei Warkentin
2011-02-12 17:05 ` Arnd Bergmann
2011-02-12 17:05 ` Arnd Bergmann
2011-02-12 17:33 ` Andrei Warkentin
2011-02-12 17:33 ` Andrei Warkentin
2011-02-12 18:22 ` Arnd Bergmann
2011-02-12 18:22 ` Arnd Bergmann
2011-02-18 1:10 ` Andrei Warkentin
2011-02-18 1:10 ` Andrei Warkentin
2011-02-18 13:44 ` Arnd Bergmann
2011-02-18 13:44 ` Arnd Bergmann
2011-02-18 19:47 ` Andrei Warkentin
2011-02-18 19:47 ` Andrei Warkentin
2011-02-18 22:40 ` Andrei Warkentin
2011-02-18 22:40 ` Andrei Warkentin
2011-02-18 23:17 ` Andrei Warkentin
2011-02-18 23:17 ` Andrei Warkentin
2011-02-19 11:20 ` Arnd Bergmann
2011-02-19 11:20 ` Arnd Bergmann
2011-02-20 5:56 ` Andrei Warkentin
2011-02-20 5:56 ` Andrei Warkentin
2011-02-20 15:23 ` Arnd Bergmann
2011-02-20 15:23 ` Arnd Bergmann
2011-02-22 7:05 ` Andrei Warkentin
2011-02-22 7:05 ` Andrei Warkentin
2011-02-22 16:49 ` Arnd Bergmann
2011-02-22 16:49 ` Arnd Bergmann
2011-02-19 9:54 ` Arnd Bergmann
2011-02-19 9:54 ` Arnd Bergmann
2011-02-20 4:39 ` Andrei Warkentin
2011-02-20 4:39 ` Andrei Warkentin
2011-02-20 15:03 ` Arnd Bergmann
2011-02-20 15:03 ` Arnd Bergmann
2011-02-22 6:42 ` Andrei Warkentin
2011-02-22 6:42 ` Andrei Warkentin
2011-02-22 16:42 ` Arnd Bergmann
2011-02-22 16:42 ` Arnd Bergmann
2011-02-11 23:23 ` Linus Walleij
2011-02-11 23:23 ` Linus Walleij
2011-02-12 10:45 ` Arnd Bergmann
2011-02-12 10:45 ` Arnd Bergmann
2011-02-12 10:59 ` Russell King - ARM Linux
2011-02-12 10:59 ` Russell King - ARM Linux
2011-02-12 16:28 ` Arnd Bergmann
2011-02-12 16:28 ` Arnd Bergmann
2011-02-12 16:37 ` Russell King - ARM Linux
2011-02-12 16:37 ` Russell King - ARM Linux
2011-02-11 22:27 ` Andrei Warkentin
2011-02-11 22:27 ` Andrei Warkentin
2011-02-12 18:37 ` Arnd Bergmann
2011-02-12 18:37 ` Arnd Bergmann
2011-02-13 0:10 ` Andrei Warkentin
2011-02-13 0:10 ` Andrei Warkentin
2011-02-13 17:39 ` Arnd Bergmann
2011-02-13 17:39 ` Arnd Bergmann
2011-02-14 19:29 ` Andrei Warkentin
2011-02-14 19:29 ` Andrei Warkentin
2011-02-14 20:22 ` Arnd Bergmann
2011-02-14 20:22 ` Arnd Bergmann
2011-02-14 22:25 ` Andrei Warkentin
2011-02-14 22:25 ` Andrei Warkentin
2011-02-15 17:16 ` Arnd Bergmann
2011-02-15 17:16 ` Arnd Bergmann
2011-02-17 2:08 ` Andrei Warkentin
2011-02-17 2:08 ` Andrei Warkentin
2011-02-17 15:47 ` Arnd Bergmann
2011-02-17 15:47 ` Arnd Bergmann
2011-02-20 11:27 ` Andrei Warkentin
2011-02-20 11:27 ` Andrei Warkentin
2011-02-20 14:39 ` Arnd Bergmann
2011-02-20 14:39 ` Arnd Bergmann
2011-02-22 7:46 ` Andrei Warkentin
2011-02-22 7:46 ` Andrei Warkentin
2011-02-22 17:00 ` Arnd Bergmann
2011-02-22 17:00 ` Arnd Bergmann
2011-02-23 10:19 ` Andrei Warkentin
2011-02-23 10:19 ` Andrei Warkentin
2011-02-23 16:09 ` Arnd Bergmann
2011-02-23 16:09 ` Arnd Bergmann
2011-02-23 22:26 ` Andrei Warkentin
2011-02-23 22:26 ` Andrei Warkentin
2011-02-24 9:24 ` Arnd Bergmann
2011-02-24 9:24 ` Arnd Bergmann
2011-02-25 11:02 ` Andrei Warkentin
2011-02-25 11:02 ` Andrei Warkentin
2011-02-25 12:21 ` Arnd Bergmann
2011-02-25 12:21 ` Arnd Bergmann
2011-03-01 18:48 ` Jens Axboe
2011-03-01 18:48 ` Jens Axboe
2011-03-01 19:11 ` Arnd Bergmann
2011-03-01 19:11 ` Arnd Bergmann
2011-03-01 19:15 ` Jens Axboe
2011-03-01 19:15 ` Jens Axboe
2011-03-01 19:51 ` Arnd Bergmann
2011-03-01 19:51 ` Arnd Bergmann
2011-03-01 21:33 ` Andrei Warkentin
2011-03-01 21:33 ` Andrei Warkentin
2011-03-02 10:34 ` Andrei Warkentin
2011-03-02 10:34 ` Andrei Warkentin
2011-03-05 9:23 ` Andrei Warkentin
2011-03-05 9:23 ` Andrei Warkentin
2011-02-11 14:41 ` Pavel Machek
2011-02-11 14:51 ` Arnd Bergmann
2011-02-11 15:20 ` Lei Wen
2011-02-11 15:25 ` Arnd Bergmann [this message]
2011-03-08 6:59 ` Pavel Machek
2011-03-08 14:03 ` Arnd Bergmann
2011-03-08 14:03 ` Arnd Bergmann
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