Initrd memory not being freed up?!

Gullible Jones · 2006-02-24 00:30:47

Right now, gnome-system-monitor, hwd, and everything else are telling me that I have 312 megs of RAM, almost all of which is in use. The thing is, they're wrong.

I have 384 megs of actual RAM; I've also got onboard video hardware blocking up 64 MB of that. That should leave 320 megs, not 312, and sure as hell did last time I looked. So what the hell happened to the other 8 megs? That quantity sounds about right for an initrd - is the memory used for that not being freed up on boot all of the sudden?! :shock:

iphitus · 2006-02-24 06:24:50

if you have an initrd that's over 32mb.... thats a problem, let alone 300mb.

cd /lib/modules/2.6.15-ARCH/ && du -hs

That's the size of every module on your system. And not even all of them are in the initrd.

Often programs report memory as being mostly used, but they ignore the fact that a large amount is used for caches and things.

RAM is a great thing. It costs the system practically nothing to store and dispose of things there. Deleting/removing something from ram is instant. There is practically 0 overhead. That's why things are cached, files on filesystem, x caches all sorts of bitmaps, browsers cache files (that's why firefox uses heaps). RAM is cheap performance.

If you're using ArchCK, and things tend to be swapped on your system, some of your ram, and maybe lots, depending on how much is swapped, will be used by 'swap prefetch'. Copying things out of swap, into free ram, in case they are about to be used. If the system needs ram, the prefetch data is purged -- removing from ram costs the system absolutely nothing. Seriously, dont even consider dropping caches or prefetch, they make things more responsive, and quicker, not less.

iphitus

Gullible Jones · 2006-02-24 18:38:07

I don't have a 32 MB initrd... The problem is that 8 MB of RAM has just *vanished* - not in caches, not in buffers, not registered anywhere by anything. If I lower the shared RAM usage by my video hardwre to 32 MB, then I have 344 MB available. 384 - 32 - 344 = 8 - that's 8 MB of RAM that's missing all the time, and though it's not enough to make any big difference, the fact that RAM can just *disappear* like that worries me quite a bit.

iphitus · 2006-02-24 20:15:31

wierd. thats all I can say.

Gullible Jones · 2006-02-24 22:58:08

I know I've got an extra stick of DDR333 lying around somewhere, I guess I'll stick that in and see if it changes things... I would think that screwy RAM would be more likely to just mess up everything though. :?

mit3z_ · 2006-02-26 14:32:49

Dont forget kernel size and loaded modules sizes. I`m missing 7 mbs on that, my vmlinuz is 1,4mb,guess modules could possibly take another 5,6mbs.

Gullible Jones · 2006-02-26 19:33:32

Memory used by kernel stuff shouldn't disappear though... And this started very very recently, this week in fact; when the initrd was first introduced, I didn't see anything like it.

Gullible Jones · 2006-03-06 23:05:34

Okay, took out my 128 MB RAM stick and used only the 256 MB one... No RAM missing, everything fine.

Put in a different 128 MB stick (also DDR333, like the others), booted up... 8 MB of RAM missing again.

So, both 128 MB sticks are for some weird reason damaged in the same way, right?

Wrong: put in both 128 MB sticks, and it's not 16 MB that's missing... It's 8.

I thought there may be something wrong with one of my RAM slots, perhaps...

But nope. One 128 MB stick always means 5 MB missing.

0, 8, 8, 8, 5... Shit. This makes no f^$king sense!

Gullible Jones · 2006-03-07 00:14:33

Shit, the thing did an emergency reboot when I tried to start Amarok! I daresay both 128 MB sticks are out for now, and I sure as hell am not going to trust MEI's RAM from now on, or anything from Panasonic... I can only hope that reboot was because of a RAM error, because if some temperature sensor has gone bad that would be the last bloody straw. :shock:

raskolnikov · 2006-03-07 03:08:17

Did you run a memtest86 on your RAM ?

Gullible Jones · 2006-03-07 03:17:45

Nope, will try, thanks.

Edit: the RAM that lead to a auto-reboot was the stick from the lightning-fried computer, my bad... Well, now I know that one more part of that machine was messed up.

Gullible Jones · 2006-03-07 03:25:29

The instructions for use of Memtest86+ don't seem quite correct to me:

pacman wrote:

==> GRUB add this to /boot/grub/menu.lst
title Memtest86+ [/boot/memtest86+/memtest.bin]
kernel (hd?,?)/memtest86+/memtest.bin

Shouldn't it be more like this?

title  Memtest86+
root   (hd0,0)
kernel /boot/memtest86+/memtest.bin root=/dev/hda1 ro
initrd /boot/initrd26.img

Or would that mess me up?

iphitus · 2006-03-07 06:03:16

it doesnt need a root= or initrd option. It's not even a piece of linux software, it just boots on its own.

iphitus

raskolnikov · 2006-03-07 11:51:33

I have never been able to boot memtest86 with lilo (I don't use grub), so I ever user floppy or a CD-RW for it... Sorry :oops:

Gullible Jones · 2006-03-07 11:55:49

iphitus wrote:

it doesnt need a root= or initrd option. It's not even a piece of linux software, it just boots on its own.
iphitus

Thanks. Does it need the 'ro' option, or does it not bother to mount anything?

tpowa · 2006-03-07 13:04:24

# (2) Memtest86+
title Memtest86+ [/boot/memtest86+/memtest.bin]
kernel (hd0,1)/memtest86+/memtest.bin

Gullible Jones · 2006-03-07 20:34:11

Thanks...

Anyway, Memtest doesn't seem to turn up any errors; in addition, it sees all the available RAM - 320 MB as opposed to 312. Very strange...

Gullible Jones · 2006-03-11 17:30:20

Nope, definitely no errors at all. Memtest sees all the RAM, my BIOS sees all the RAM, and my operating system sees 8 MB missing, and *only* when I use one of the 128MB sticks. What the hell is going on here?

tpowa · 2006-03-11 17:33:22

also initrd uses more then 8mb ram, it's tuned for 16mb.

Gullible Jones · 2006-03-11 17:53:04

Then what could this be?

Arch Linux

#1 2006-02-24 00:30:47

Initrd memory not being freed up?!

#2 2006-02-24 06:24:50

Re: Initrd memory not being freed up?!

#3 2006-02-24 18:38:07

Re: Initrd memory not being freed up?!

#4 2006-02-24 20:15:31

Re: Initrd memory not being freed up?!

#5 2006-02-24 22:58:08

Re: Initrd memory not being freed up?!

#6 2006-02-26 14:32:49

Re: Initrd memory not being freed up?!

#7 2006-02-26 19:33:32

Re: Initrd memory not being freed up?!

#8 2006-03-06 23:05:34

Re: Initrd memory not being freed up?!

#9 2006-03-07 00:14:33

Re: Initrd memory not being freed up?!

#10 2006-03-07 03:08:17

Re: Initrd memory not being freed up?!

#11 2006-03-07 03:17:45

Re: Initrd memory not being freed up?!

#12 2006-03-07 03:25:29

Re: Initrd memory not being freed up?!

#13 2006-03-07 06:03:16

Re: Initrd memory not being freed up?!

#14 2006-03-07 11:51:33

Re: Initrd memory not being freed up?!

#15 2006-03-07 11:55:49

Re: Initrd memory not being freed up?!

#16 2006-03-07 13:04:24

Re: Initrd memory not being freed up?!

#17 2006-03-07 20:34:11

Re: Initrd memory not being freed up?!

#18 2006-03-11 17:30:20

Re: Initrd memory not being freed up?!

#19 2006-03-11 17:33:22

Re: Initrd memory not being freed up?!

#20 2006-03-11 17:53:04

Re: Initrd memory not being freed up?!

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