Messages in this thread |  | | Date | Wed, 11 Sep 2002 19:59:39 +0530 | From | Dipankar Sarma <> | Subject | Re: [PATCH] Read-Copy Update 2.5.34 |
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On Wed, Sep 11, 2002 at 10:03:28AM -0400, Robert Love wrote: > On Wed, 2002-09-11 at 08:20, Dipankar Sarma wrote: > > > vanilla-2.5.34 rcu_poll-2.5.34 > > -------------- --------------- > > 80 , 40 , 1.593 1.569 > > 112 , 40 , 1.544 1.554 > > 144 , 40 , 1.595 1.552 > > 176 , 40 , 1.568 1.605 > > 198 , 40 , 1.562 1.577 > > 230 , 40 , 1.563 1.583 > > 244 , 40 , 1.671 1.638 > > > > Not sure how reliable these numbers are. > > And how bad is the performance drop from 2.5.34-preempt to > 2.5.34-preempt-rcu? > > I am glad you guys support kernel preemption (not that you have a chance > at this point) but I hope it was not an afterthought.
Hi Robert,
Sorry, I should have been more careful labelling them - those are 2.5.34-preempt vs 2.5.34-preempt-rcu numbers. I did them first because rcu-poll-preempt kernel has a conditinal branch in fast path and hence more interesting. I will publish the vanilla vs rcu_poll reflex numbers in a few minutes from now.
The preemption support have been in RCU for a very long time. IIRC, I added it in around 2.5.14.
See http://marc.theaimsgroup.com/?l=linux-kernel&m=102084967517192&w=2
Our OLS paper and presentation too deals with preemption -
http://www.rdrop.com/users/paulmck/rclock/rcu.2002.07.08.pdf http://www.rdrop.com/users/paulmck/rclock/rclock.OLS.2002.07.08a.pdf
Thanks -- Dipankar Sarma <dipankar@in.ibm.com> http://lse.sourceforge.net Linux Technology Center, IBM Software Lab, Bangalore, India. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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