Dear Friends,
Many thanks for your links.
I want a driver, not device.
Long back in 2013 I wrote a driver,
following Rusty's paper, "Towards a de facto standard..."
which used to fill only one descriptor chain
(the header-buffer-status chain for blk device) into available ring.
And after kick, when I get an IRQ,
I collect the data and then proceed to fill another such a request.
It felt sequential.
I read that, even before a single kick,
many such chains can be fit into available ring.
And thus getting the benefit of parallel execution of all requests.
Which is parallel.
But I couldn't do it.
And meanwhile that standard 0.95 was obsolete.
Now we have 1.0. Not sure how big the difference it brings.
So wanted to see a driver which takes benefit of parallelism.
And works with IRQ mechanism.
Say, I fill up 4 such requests and fired a single kick.
Will device interrupt me 4 times with IRQ?
I hope so...then only the benefit of parallelism comes...right?
But if so, when driver accesses used ring,
how can device use it to place the next served index?
Can there be a chance of IRQ miss?
Wanted to know about all this...
With thanks and best regards,
Yours sincerely,
Srinivas Nayak
Home: http://www.mathmeth.com/sn/
Blog: http://srinivas-nayak.blogspot.in/
On 06/08/2016 04:40 PM, Ian Campbell wrote:
