Re: [PATCH v2 0/6] crypto: SHA1 multibuffer implementation

[Tim Chen <tim.c.chen@linux.intel.com>]

On Fri, 2014-05-30 at 17:26 +0800, Herbert Xu wrote:
> On Fri, May 23, 2014 at 04:02:12PM -0700, Tim Chen wrote:
> >
> > The outline of the algorithm is sketched below:
> > Any driver requesting the crypto service will place an async
> > crypto request on the workqueue.  The multi-buffer crypto daemon will
> > pull request from work queue and put each request in an empty data lane
> > for multi-buffer crypto computation.  When all the empty lanes are filled,
> > computation will commence on the jobs in parallel and the job with the
> > shortest remaining buffer will get completed and be returned.  To prevent
> > prolonged stall when there is no new jobs arriving, we will flush a crypto
> > job if it has not been completed after a maximum allowable delay.
> 
> I'm a bit uncomfortable with the idea of only having a delay here.
> How about in addition to the delay we also flush the queue as
> soon as the CPU is idle?

It's a good idea to get the jobs processed with flush when there are cpu
cycles nobody else is using. I'll have to think a bit of what mechanism
to use to implement this.  Any suggestions will be welcomed.

Tim