Re: [PATCH] RCU for low latency (experimental)

Dipankar Sarma
2004-03-23T12:35:17Z

On Tue, Mar 23, 2004 at 01:29:25PM +0100, Andrea Arcangeli wrote:
> On Tue, Mar 23, 2004 at 03:47:55PM +0530, Dipankar Sarma wrote:
> > Here is the RCU patch for low scheduling latency Andrew was talking
> > about in the other thread. I had done some measurements with
>
> I don't see why you're using an additional kernel thread. I told you one
> way to implement it via softirq taking advantage of the scheduler-friendy
> re-arming tasklets.

I have a patch for that too which I have been testing for DoS in
route cache, not latency. It is worth testing it here, however
I think re-arming tasklets is not as friendly to latency as
executing the rcu callbacks from process context. One thing
I have noticed is that more softirqs worsen latency irrespective
of the worst-case softirq length.

Thanks
Dipankar