Vmalloc Information Needed

Arun KS getarunks at gmail.com
Tue Mar 25 07:47:03 EDT 2014


Hi Pramod,

On Tue, Mar 25, 2014 at 5:08 PM, pramod gurav
<pramod.gurav.etc at gmail.com> wrote:
> Hi Arun,
>
>
> On Tue, Mar 25, 2014 at 3:55 PM, Arun KS <getarunks at gmail.com> wrote:
>>
>> Hello Anup,
>>
>> On Sun, Mar 23, 2014 at 9:54 AM, Anup Buchke <anup.estuff at gmail.com>
>> wrote:
>> > For a user/kernel configuration of 3/1GB and (0-16M DMA , 16-896 - Low ,
>> > 896
>> > - 1024 - High )
>> > Q: Is amount of memory allocated to Vmalloc limited to 128MB?
>> No. 128MB is the default vmalloc size. You can override by kernel boot
>> argument vmalloc=n[KMG]
>
>
> Ok. So will this reduce(adjust) the LOW_MEM and add that reduced LOW_MEM to
> HIGH_MEM region in virtual address space?

Exactly.

Thanks,
Arun

>>
>>
>> Thanks,
>> Arun
>> >
>> > I read an article which said to increase the Vmalloc allocation size we
>> > need
>> > to either
>> > 1) Change user/kernel distribution like 2.75/1.25 which proportionately
>> > increase the address space available to High memory
>> > 2) For a fixed user/kernel distribution reduce the low memory like
>> > 16-800
>> > thereby increasing the size available for high memory.
>> >
>> > In either of the case the memory for vmalloc is limited to user/kernel
>> > distribution . i.e. the amount of virtual address space available in
>> > high
>> > memory.
>> >
>> > I am a beginner, so please let me know if my understanding is
>> > correct..and
>> > rectify in-case of wrong.?
>> >
>> > Thanks,
>> > Anup Buchke.
>> >
>> > _______________________________________________
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>> >
>>
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>
>
>
>
> --
> Thanks and Regards
> Pramod



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