On Thu, Nov 19, 2009 at 15:16, Matthew Garrett <mjg59@xxxxxxxxxxxxx> wrote: > On Thu, Nov 19, 2009 at 02:29:29PM +0100, Kay Sievers wrote: >> On Thu, Nov 19, 2009 at 14:01, Matthew Garrett <mjg@xxxxxxxxxx> wrote: >> > On Thu, Nov 19, 2009 at 12:09:30PM +0100, Kay Sievers wrote: >> >> On Wed, Nov 18, 2009 at 22:33, Matthew Garrett <mjg59@xxxxxxxxxxxxx> wrote: >> >> > My use cases are on the order of a second. >> >> >> >> Ok, what's the specific use case, which should be triggered after a >> >> second? I thought you were thinking about disk spindown or similar. >> > >> > The first is altering ALPM policy. ALPM will be initiated by the host if >> > the number of queued requests hits zero - if there's no hysteresis >> > implemented, then that can result in a significant performance hit. We >> > don't need /much/ hysteresis, but it's the difference between a 50% >> > performance hit and not having that. >> >> Can't that logic live entirely in the kernel, instead of being a >> rather generic userspace event interface (with the current limitation >> to a single user)? > > It could, but it seems a bit of a hack. It'd still also require the > timer to be in the kernel, so we might as well expose that to userspace. Sure, but a userspace configurable policy for an in-kernel disk-idle powermanagent sounds fine, compared to a single-subscriber userspace-only disk-idle event interface. :) Kay -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
