How to measure the RAM read/write performance

Gaurav Jain gjainroorkee at gmail.com
Tue Feb 26 07:06:41 EST 2013


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 at gmail.com>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,
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>


-- 
Gaurav Jain
Associate Software Engineer
VxVM Escalations Team, SAMG
Symantec Software India Pvt. Ltd.
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