Re: How to measure the RAM read/write performance

[sandeep kumar <coolsandyforyou@xxxxxxxxx>]

>Try below points:
>1. I am not sure about snapdragon(is it Qualcomm?) but try
>CONFIG_CPU_DCACHE_DISABLE.

I did that already, device is not booting. In our architecture cache is tightly coupled with CPU.

>2. You are better off programming some DMA master to do large (and
>uncached) reads/writes to RAM and timing that.

DMA is not a standard way, i suppose, as it depends on what I/O peripheral we are doing the DMA. 

>You should always add arm mailing list and please mention the chip set details.
>cat /proc/cpuinfo is a great way

Processor       : ARMv7 Processor rev 2 (v7l)

BogoMIPS        : 163.38

Features        : swp half thumb fastmult vfp edsp neon vfpv3 tls

CPU implementer : 0x51

CPU architecture: 7

CPU variant     : 0x1

CPU part        : 0x00f

CPU revision    : 2

Thanks

Sandeep

On Wed, Feb 27, 2013 at 5:37 PM, anish singh <anish198519851985@xxxxxxxxx> wrote:

On Tue, Feb 26, 2013 at 5:01 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.

Try below points:
1. I am not sure about snapdragon(is it Qualcomm?) but try
CONFIG_CPU_DCACHE_DISABLE.
2. You are better off programming some DMA master to do large (and
uncached) reads/writes to RAM and timing that.

However simple uncached LDR/STR from the CPU may not be a great
measure of RAM controller perf.

You should always add arm mailing list and please mention the chip set details.
cat /proc/cpuinfo is a great way

>
> How can i achieve this...Any ideas/suggestions...?
>
> --
> With regards,
> Sandeep Kumar Anantapalli,
>

> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@xxxxxxxxxxxxxxxxx
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>

--
With regards,
Sandeep Kumar Anantapalli,

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