From: Selwyn Tang <selwyn@hectrix.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Subject: Re: high cpu usage using nftl for DOC2000
Date: Thu, 09 Oct 2003 11:54:12 +0800 [thread overview]
Message-ID: <3F84DBE4.6030602@hectrix.com> (raw)
In-Reply-To: <1065608571.22298.92.camel@hades.cambridge.redhat.com>
On 10/08/2003 06:22 PM, David Woodhouse wrote:
> noatime
> Access timestamps are not updated when a file is read.
>
> With atime enabled, every _read_ of a file or directory causes a write
> to the flash, because the 'access timestamp' is updated.
>
> On flash, this is a Bad Thing(tm).
I now set fstab to mount it with noatime, but it doesn't help the problem.
Besides, I added a printk to each function in nftlcore.c, printing the
name of the function when it is called, eg. "mtdcore: init_mtd". Then in
boot up, I got the followings:
/**** begin ****/
mtdcore: init_mtd
mtdcore: register_mtd_user
NFTL driver: nftlcore.c $Revision: 1.94 $, nftlmount.c $Revision: 1.34 $
DiskOnChip 2000 found at address 0xD4000
Flash chip found: Manufacturer ID: 98, Chip ID: 73 (Toshiba:NAND 16MiB 3,3V)
1 flash chips found. Total DiskOnChip size: 16 MiB
mtdcore: add_mtd_device
mtd: Giving out device 0 to DiskOnChip 2000
NFTL: add_mtd for DiskOnChip 2000
NFTL: UnitSizeFactor 0x00 detected. This violates the spec but we think
we know what it means...
nftla: nftla1
/**** end ****/
There are only three mtdcore printk messages here: init_mtd,
register_mtd_user and add_mtd_device. Then I cat'd /proc/kmsg and ls'd
/mnt/doc. nftld immediately held all my cpu time, and /proc/kmsg didn't
give me any messages.
Where should I add printk to to get more clues?
Selwyn
next prev parent reply other threads:[~2003-10-09 3:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-02 6:54 high cpu usage using nftl for DOC2000 edward jose
2003-10-03 2:07 ` Selwyn Tang
2003-10-03 5:54 ` David Woodhouse
2003-10-03 8:22 ` Selwyn Tang
2003-10-03 8:52 ` David Woodhouse
2003-10-08 9:46 ` Selwyn Tang
2003-10-08 9:58 ` David Woodhouse
2003-10-08 10:16 ` Selwyn Tang
2003-10-08 10:22 ` David Woodhouse
2003-10-09 3:54 ` Selwyn Tang [this message]
2003-10-09 6:30 ` David Woodhouse
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