Re: Initial bits to help pull jiffies out of drivers

From: Arjan van de Ven
Date: Tue Aug 03 2004 - 03:29:43 EST


On Tue, 2004-07-27 at 21:59, Alan Cox wrote:
> This is really for comment, the basic idea is to add some relative
> timer functionality. This gives us timeout objects as well as pulling
> jiffies use into one place in the timer code. The need for the old
> interfaces never goes away however because some code uses a previous
> event base to construct timeouts to avoid sliding due to the latency
> between service and re-addition.
>
> (please cc me on comments)

My gripe with this is that the interface still is relative-to-HZ time.
I'm convinced that driver(writers) are better off with an absolute time
interface, eg add_timeout_ms(), add_timeout_us() etc.
(which btw also give a hint about the accuracy required, so that the
kernel can group milisecond delays together even when they got scheduled
at different usecs, once we get timers that accurate)

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