Ram Disk

Ram Disk

[Julia Elbert]

Hi All,

I am running a 7mg ram disk in my 860t. I have multiple programs I start
through linuxrc. I am streaming video, serial data, and running a web server
on various sockets. The webserver is GoAhead. When I click on a cgi script
my system crashes with

Software Emulation Web/62 NIP: 1009a014 *NIP: 0x0 code: ffffffdaSoftware
Emulati
on linuxrc/6 NIP: 1009a014 *NIP: 0x0 code: ffffffdasash-2.03#

Am I running out of ram? I have 16 mgs.

Thanks in advance....
--Julia

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Re: Ram Disk

[Jacob Chen]

Hi,

> Software Emulation Web/62 NIP: 1009a014 *NIP: 0x0 code: ffffffdaSoftware
> Emulati
> on linuxrc/6 NIP: 1009a014 *NIP: 0x0 code: ffffffdasash-2.03#

Can you post how did John show you to fix this problem?  Thanks.

Jacob
----- Original Message -----
From: "Julia Elbert" <jelbert@enerdyne.com>
To: <linuxppc-embedded@lists.linuxppc.org>
Sent: Thursday, August 24, 2000 12:12 PM
Subject: Ram Disk


>
> Hi All,
>
> I am running a 7mg ram disk in my 860t. I have multiple programs I start
> through linuxrc. I am streaming video, serial data, and running a web
server
> on various sockets. The webserver is GoAhead. When I click on a cgi script
> my system crashes with
>
> Software Emulation Web/62 NIP: 1009a014 *NIP: 0x0 code: ffffffdaSoftware
> Emulati
> on linuxrc/6 NIP: 1009a014 *NIP: 0x0 code: ffffffdasash-2.03#
>
> Am I running out of ram? I have 16 mgs.
>
> Thanks in advance....
> --Julia
>


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Ram Disk

[thanh]

HELLO,

Jacob Chen wrote:

> Hi,
>
> > Software Emulation Web/62 NIP: 1009a014 *NIP: 0x0 code: ffffffdaSoftware
> > Emulati
> > on linuxrc/6 NIP: 1009a014 *NIP: 0x0 code: ffffffdasash-2.03#
>
> Can you post how did John show you to fix this problem?  Thanks.
>
> Jacob

CAN YOU POST HOW DID YOU FIX THIS PROBLEM, PLS.
THANKS.
JARI


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RE: Ram Disk

[Julia Elbert]

Hi,
Hi Jari,
Maybe you were talking to Jacob? Hmmm.
I have posted this already. Look at 8/24. But here you go and feel free to
post it again if you like.
Thanks,
Julia

>From John's note my code change was as follows:
I moved a close comment down 5 lines.

lines 405 - 409 commented out in linux/mm/vmscan.c

/* Then, try to page stuff out..
		while (swap_out(priority, gfp_mask)) {
			if (!--count)
				goto done;
		}
*/

John wrote:

In *my* code (I am running a modified 2.2.15 kernel), I merely commented out
the "swap_out ()" code in routine do_try_to_free_pages in mm/vmscan.c (in my
code, it's lines 405-409).  Since I made this change, my system has been
rock-steady (and I run a LOT of applications, including the Apache web
server and various CGI scripts I have written).  I now see free memory go
down as new images are read from the ramdisk, and back up as memory is freed
by the system.
Hope this helps your problem...
John Whitney


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RAM disk

[Ugu Barr jr.]

Hi there,

I would like to study the code of the Linux RAM Disk.
Could someone, please point me where to start.

Thanks,
Ugu

RAM disk

[Greg Freemyer]

On Mon, Jan 17, 2011 at 5:07 PM, Ugu Barr jr. <ugubarr@mail.com> wrote:
> Hi there,
>
> I would like to study the code of the Linux RAM Disk.
> Could someone, please point me where to start.
>
> Thanks,
> Ugu

Do you just want to look at the code?

If so: the linux kernel source browser is nice starting point.

http://lxr.linux.no

I put ram disk in the search box and one of the first results was the
internal kernel doc file for the ram disk:

http://lxr.linux.no/#linux+v2.6.37/Documentation/blockdev/ramdisk.txt

That file is a little out of date because it talks about rdev, which
was deleted from util-linux last summer I think.  I don't know what
tool / process takes it's place.

If you figure it out, write a patch to the doc file and get your name
memorialized in the kernel git log!

A little more poking around at lxr.linux.no gets you to
http://lxr.linux.no/#linux+v2.6.37/drivers/block/brd.c

Which I think is the source code your looking for.

Greg

RAM disk

[Ugu Barr jr.]

>> drivers/block/brd.c Which I think is the source code your looking for
 


Yes, thank you. :-)


Ugu,


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