Re: workqueue thing

Herbert Xu
2009-12-23T06:53:52Z

On Wed, Dec 23, 2009 at 12:37:32PM +0900, Tejun Heo wrote:
>
> I wrote this before but if something is burning CPU cycles using MT
> workqueues, this can be easily supported by marking such workqueue as
> not concurrency-managed. ie. Works queued for such workqueues
> wouldn't contribute to the perceived workqueue concurrency and will be
> left to be managed solely by the scheduler. This will completely
> cover the crypto_wq case which uses MT workqueue with local cpu
> binding.

Right, the main use of workqueues in the crypto subsystem currently
is to perform operations in a process context, e.g., in order to
use SSE instructions on x86, so there is no real parallelism
involved.

However, Steffen Klassert has proposed a parallelisation mechanism
whereby extremely CPU-intensive operations such as encryption may
be split across CPUs. Steffen, could you repost your padata patches
here?

Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt