Re: TREE_SRCU slows hotplug by factor ~16

From: Paul E. McKenney
Date: Thu Apr 27 2017 - 00:11:54 EST


On Thu, Apr 27, 2017 at 05:43:59AM +0200, Mike Galbraith wrote:
> On Wed, 2017-04-26 at 20:12 +0200, Mike Galbraith wrote:
> > On Wed, 2017-04-26 at 10:56 -0700, Paul E. McKenney wrote:
> >
> > > > OK, I do need to do more work. My current guess is that I should have
> > > > set the default for srcutree.exp_holdoff to 25*1000 instead of 50*1000.
> > > > But I am sure that further data will show me the error of my ways. ;-)
> >
> > I can give that a go tomorrow (too crispy now).
>
> real 0m39.177s
> user 0m0.225s
> sys 0m5.344s
>
> tadaaa (tricorder noises... it's dead Jim)

This is with srcutree.exp_holdoff set to 25*1000? If so, great news!
Really easy to adjust the default. ;-)

Thanx, Paul