Re: Extermeley large PageTables over 500G on kernel 2.6.32.49 (SLES11SP1)

From: Avi Kivity
Date: Wed Jan 11 2012 - 06:26:46 EST


On 01/11/2012 12:52 PM, Borzenkov, Andrey wrote:
> > If not, its normal to eat so much memory for page tables
> >
> > grep VmPTE /proc/*/status
> >
> >
>
> Forgive my ignorance. I thought that
>
> 1. PTE is 8 bytes per page, which is 4K which gives 2K per 1M of memory
> 2. All processes sharing the same shared memory share the same page table
>
> So page table for Oracle SGA 500G would be around 1G and shared by all Oracle clients. Is my assumption incorrect?
>

The second assumption is incorrect. So fully populated the 2000
processes would consume 2T; they just haven't accessed all the SGA yet.

--
error compiling committee.c: too many arguments to function

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