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From: Fortini Matteo <matteo.fortini@mta.it>
To: Kenneth Johansson <kenneth@southpole.se>
Cc: linux-ppc list <linuxppc-dev@ozlabs.org>
Subject: Re: Acceleration for map_copy_from on powerpc 512x
Date: Tue, 27 Oct 2009 11:02:07 +0100	[thread overview]
Message-ID: <4AE6C51F.9050203@mta.it> (raw)
In-Reply-To: <1256135453.22238.27.camel@kenjo-laptop>

The simple_map_init() works at a higher level, what I'm redefining is a 
function called by mtd->read()

The block size for e.g. a dd if=/dev/mtd0 of=/dev/null
with the default block size (I believe it's 512Bytes), fetches from 
/dev/mtd0 4096 Bytes at a time.
I'd prefer the kernel to be scheduling other tasks meanwhile, instead of 
busy-waiting on completion.

Regards

Kenneth Johansson ha scritto:
> On Mon, 2009-10-19 at 09:52 +0200, Fortini Matteo wrote:
>
>   
>> I didn't find a cleaner way than just #ifdef'ing the map_copy_from call 
>> and substitute with my call on relevant cases. I wonder if there is a 
>> cleaner way.
>>     
>
> Remove the call to simple_map_init() and do it manually in your driver
> with your own functions.
>
>   
>> And yes, as soon as I've cleaned up the code a little bit, I will 
>> definitely post a patch about it.
>>
>> Moreover: a huge benefit would come from exploiting DMA on these 
>> transfers, 
>>     
>
> probably depends on the block size if it's a gain or not. What is the
> size you normally see. 
>
>
>   

  reply	other threads:[~2009-10-27 10:02 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-19  7:52 Acceleration for map_copy_from on powerpc 512x Fortini Matteo
2009-10-21 14:30 ` Kenneth Johansson
2009-10-27 10:02   ` Fortini Matteo [this message]
2009-10-27 11:41     ` Kenneth Johansson

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