Messages in this thread | | | Date | Thu, 25 Sep 2008 07:18:09 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH, RFC] v6 scalable classic RCU implementation |
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On Thu, Sep 25, 2008 at 09:29:15AM +0200, Ingo Molnar wrote: > > * Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote: > > > Attached is an updated patch to Classic RCU that applies a hierarchy, > > greatly reducing the contention on the top-level lock for large > > machines. This passes 10-hour concurrent rcutorture and > > online-offline testing on 128-CPU ppc64 without dynticks enabled, and > > exposes some timekeeping bugs in presence of dynticks (exciting > > working on a system where "sleep 1" hangs until interrupted...). > > i'm wondering about those timekeeping bugs. Do you have an idea what's > it about and does it affect mainline?
Sad to say, they do affect mainline -- I can reproduce these problems in 2.6.27-rc7. Thomas has given me a couple of fixes that got rid of earlier problems in which jiffies would stop counting, and I believe has located the cause of at least one other problem.
Thanx, Paul
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