On Thu, 2012-05-10 at 14:08 -0500, Robert Jennings wrote: > * Benjamin Herrenschmidt (benh@xxxxxxxxxxxxxxxxxxx) wrote: > > Is this meant to be called in atomic context ? If not, maybe it should > > at the very least do a cond_resched() ? > > > > Else, what about ceding the processor ? Or at the very least reducing > > the thread priority for a bit ? > > > > Shouldn't we also enforce to always have a timeout ? IE. Something like > > 30s or so if nothing specified to avoid having the kernel just hard > > lock... > > > > In general I don't like that sort of synchronous code, I'd rather return > > the busy status up the chain which gives a chance to the caller to take > > more appropriate measures depending on what it's doing, but that really > > depends what you use that synchronous call for. I suppose if it's for > > configuration type operations, it's ok... > > This function is called in atomic context, it is used by PFO-type device > drivers to perform operations with the nest accelerator unit (like > crypto acceleration). > > Having the timeout and retries in this function is the wrong thing to do. > We'll resubmit this without the loop and the caller will be responsible for > retrying the operations. > > I would rather have the caller cede the processor or alter thread > priority where appropriate than doing that in this function. I don't > think this should be done in this crypto driver. That sounds right indeed... as long as the upper crypto layer has a concept of "try again later"... if it doesn't it will result in random funny failures :-) Cheers, Ben. -- 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
