Re: [PATCH/RFCv4 0/6] The Contiguous Memory Allocator framework

From: KAMEZAWA Hiroyuki
Date: Wed Aug 25 2010 - 23:49:52 EST


On Thu, 26 Aug 2010 11:50:17 +0900
KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:

> 128MB...too big ? But it's depend on config.
>
> IBM's ppc guys used 16MB section, and recently, a new interface to shrink
> the number of /sys files are added, maybe usable.
>
> Something good with this approach will be you can create "cma" memory
> before installing driver.
>
> But yes, complicated and need some works.
>
Ah, I need to clarify what I want to say.

With compaction, it's helpful, but you can't get contiguous memory larger
than MAX_ORDER, I think. To get memory larger than MAX_ORDER on demand,
memory hot-plug code has almost all necessary things.

you may able to add
# echo 0xa0000000-0xa80000000 > /sys/devices/system/memory/cma

to get contiguous isolated memory.

BTW, just curious...the memory for cma need not to be saved at
hibernation ? Or drivers has to write its own hibernation ops by driver suspend
udev or some ?



Thanks,
-Kame

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