Re: [Bug #11342] Linux 2.6.27-rc3: kernel BUG at mm/vmalloc.c -bisected

From: Bernd Petrovitsch
Date: Wed Aug 27 2008 - 04:45:24 EST


On Tue, 2008-08-26 at 22:16 -0400, Parag Warudkar wrote:
[...]
> Well, sure - but the industry as a whole seems to have gone the other

"The industry as a whole" doesn't exist on that low level. You can't
compare the laptop and/or desktop computer market (where one may buy
today hardware that runs in 3 years with the next generation/release of
the OS and applications) with the e.g. "WLAN router" market where - from
the commercial point of view - every Euro counts (and where the
requirements for the lifetime of the device are long frozen before the
thing gets in a shop).

> way - do more with more at the similar or lower price points!
> By that definition of less is better we should try and make the kernel
> memory pageable (or has someone already done that?) - Windows does it,

That doesn't help as in really small devices (like WLAN routers, cable
modems, etc.) you run without any means of paging/swapping. And even
binaries/read-only files are not necessarily executable in place (but
must be loaded into RAM). So you can't flush these pages.

And pageable kernel memory doesn't come for free - even if one only
counts the increased code and it's complexity.

> by default ;)

Which is more a sign that it is probably a very bad idea.

Bernd
--
Firmix Software GmbH http://www.firmix.at/
mobil: +43 664 4416156 fax: +43 1 7890849-55
Embedded Linux Development and Services


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