Messages in this thread | | | Date | Wed, 25 May 2011 18:13:10 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [tip:core/rcu] Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" |
| |
On Wed, May 25, 2011 at 03:49:25PM -0700, Yinghai Lu wrote: > On 05/25/2011 03:34 PM, Paul E. McKenney wrote: > > On Wed, May 25, 2011 at 03:15:50PM -0700, Yinghai Lu wrote: > >>> There is a new branch yinghai.2011.05.24a on: > >>> > >>> git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git > >>> > >>> Or will be as soon as kernel.org updates its mirrors. > >>> > >>> I am not sure I could call this "clean", but it does revert that commit > >>> and 11 of the subsequent commits that depend on it. It does build, > >>> and I will test it once my currently running tests complete. > >> > >> yes, with those revert, there is no delay in 10 times booting. > > > > Unfortunately, there are rcutorture test failures with the revert... > > confused.
Given what I had to do to generate the revert, not exactly a surprise, I am afraid. Just means that the resulting RCU sometimes fails to wait for all pre-existing readers, and rcutorture catches it.
> what is the next?
1. I send you a patch that I hope will fix the softlockup you saw. I am testing this.
2. I am working on more detailed instrumentation, and will send a patch on that.
3. If time allows, break down the operations RCU is doing and test them in isolation.
Other thoughts?
Thanx, Paul
| |