* Evgeniy Polyakov | 2007-06-22 15:57:26 [+0400]: >On Fri, Jun 22, 2007 at 03:28:44PM +0800, Herbert Xu (herbert@xxxxxxxxxxxxxxxxxxx) wrote: >> > + * Actually I need to think about how to handle the case, when queue is full. >> > + * So far error (-EINVAL) is returned. >> > + */ >> >> OK you need to provide a software queue here. Since you already >> have a hardware queue, you may choose to have a queue with a >> (advisory) maximum length of zero. However, a queue is still >> necessary since requests with the MAY_BACKLOG flag must never >> be discarded. >> >> This is (or will be) used by users such as dm-crypt that must be >> able to add at least one request but can throttle themselves >> afterwards . > >What will prevent crypto user from filling that queue with crypto >requests more and more when hardware is not capable to work with such >rate? Nothing, the hw signalizes with -EBUSY such a state and the crypto user has to slow down. If the crypto user continues such a behavior, the system will go OOM (this is atleast my understanding). >-- > Evgeniy Polyakov Sebastian - To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
