| Date | Fri, 31 Aug 2012 11:24:29 -0700 | From | Josh Triplett <> | Subject | Re: [PATCH tip/core/rcu 11/15] rcu: Avoid spurious RCU CPU stall warnings |
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On Thu, Aug 30, 2012 at 11:56:24AM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" <paul.mckenney@linaro.org> > > If a given CPU avoids the idle loop but also avoids starting a new > RCU grace period for a full minute, RCU can issue spurious RCU CPU > stall warnings. This commit fixes this issue by adding a check for > ongoing grace period to avoid these spurious stall warnings. > > Reported-by: Becky Bruce <bgillbruce@gmail.com> > Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> --- > kernel/rcutree.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index fbe43b0..e58097b 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -820,7 +820,8 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) > j = ACCESS_ONCE(jiffies); > js = ACCESS_ONCE(rsp->jiffies_stall); > rnp = rdp->mynode; > - if ((ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && ULONG_CMP_GE(j, js)) { > + if (rcu_gp_in_progress(rsp) && > + (ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && ULONG_CMP_GE(j, js)) { > > /* We haven't checked in, so go dump stack. */ > print_cpu_stall(rsp); > -- > 1.7.8 >
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