Re: Crypto Update for 2.6.38

Linus Torvalds
2011-01-06T21:24:30Z

On Thu, Jan 6, 2011 at 1:16 PM, Herbert Xu <herbert@gondor.hengli.com.au> wrote:
> On Thu, Jan 06, 2011 at 10:05:46AM -0800, Linus Torvalds wrote:
>>
>> Is there really any point to this? And can we get more explanation of
>> what the interface is, and who would use it?
>
> I think you've answered it yourself in the third paragraph :)

No I didn't.

What part of "can we get more explanation of what the interface is" is unclear?

Explanations of interface. Code. Who uses it? What are the actual
performance benefits on real code?

Quite frankly, asynchronous external devices using DMA or similar are
seldom real performance improvements. The bus and cache traffic tends
to overwhelm any other advantage, and commonly the result is (a) lower
performance with (b) better-looking profiles.

But "better-looking profiles" isn't actually a real advantage.

And I really do want to hear about new kernel interfaces. What _are_
the interfaces, and what are the advantages to them.

Linus