Re: slow eMMC write speed

Andrei E. Warkentin
2011-10-21T04:45:08Z

2011/10/20 Praveen G K <praveen.gk@gmail.com>:
>>
>> So you did 10 back-to-back 64k transfers inside the request handling routine, and you noticed that caused a smaller GC delay
>> rather than doing 10 separate multiblock 64k transfers the normal way?
> That's right.  Even though the request is supposed to service only
> 64k, I sent 10 write commands each with 64k and then completed the
> request (within the loop that takes care of the read/writes in
> block.c) with the same data.
>
> So, instead of calling blk_end_request just after one write, I call
> blk_end_request after 10 writes.
>

Well, if you're just writing 10 times the data to the *same* location
(since it's inside the loop), then of course
your noticed GC delay is smaller when compared to writing 10 times to
different locations - the garbage collection happens
when the card notices you are writing to more allocation units than
are cached internally...

A