Re: [RFC PATCH v2 1/9] crypto: qce: Add core driver implementation

From: Herbert Xu
Date: Mon Apr 28 2014 - 04:59:55 EST


On Mon, Apr 14, 2014 at 03:48:37PM +0300, Stanimir Varbanov wrote:
>
> +#define QCE_MAJOR_VERSION5 0x05
> +#define QCE_QUEUE_LENGTH 50

What is the purpose of this software queue? Why can't you directly
feed the requests to the hardware?

If the hardware can't handle more than 50 requests in-flight,
then your software queue has failed to handle this since you're
taking requests off the queue before you touch the hardware so
you're not really limiting it to 50. That is, for users that
can wait you're potentially dropping their requests instead
of letting them wait through the backlog mechanism.

Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/