Re: How to measure the RAM read/write performance

[Gaurav Jain <gjainroorkee@xxxxxxxxx>]

The mechanism to disable the L1/L2 memory caches of the CPU will depend on the processor architecture itself. This can be possibly be done at kernel boot-time or more preferably, in your case, through a kernel module.

For Intel x86, the kernel module would look something like following: (The key is setting bit 30 of the control register cr0)

mov eax,cr0
or eax, 40000000H ;set bit 30 without clearing the others
mov cr0,eax

Reference: 

http://stackoverflow.com/questions/1108485/disable-l2-l1-caches

http://dirac.org/linux/writing/lkmpg/2.6/lkmpg-2.6.0.html

~ Gaurav

On Tue, Feb 26, 2013 at 12:31 PM, sandeep kumar <coolsandyforyou@xxxxxxxxx> wrote:

Hi All

In performance benchmark tools, When we profile read/write timings mostly, those read/writes are done to cache only.

I want to measure my DDR(RAM chip) performance.

So i want to make sure, every read/write should happen to DDR RAM chip only.

How can i achieve this...Any ideas/suggestions...?

--
With regards,
Sandeep Kumar Anantapalli,

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--

Gaurav Jain

Associate Software Engineer

VxVM Escalations Team, SAMG

Symantec Software India Pvt. Ltd.

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