Messages in this thread | | | Subject | Re: [PATCH] rcu: Fix up pending cbs check in rcu_prepare_for_idle | From | Neeraj Upadhyay <> | Date | Mon, 7 Aug 2017 19:31:27 +0530 |
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On 08/07/2017 06:10 PM, Paul E. McKenney wrote: > On Mon, Aug 07, 2017 at 11:20:10AM +0530, Neeraj Upadhyay wrote: >> Pending cbs check in rcu_prepare_for_idle is inversed >> in the sense that, it should accelerate if there are >> pending cbs; but, the check does the opposite. So, >> fix it. >> >> Fixes: 15fecf89e46a ("srcu: Abstract multi-tail callback list handling") >> Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org> > Good catch! Queued for review and testing. > > Just out of curiosity, how did you find this one? > > Thanx, Paul
Hi Paul, found the issue while reading the code.
> >> --- >> kernel/rcu/tree_plugin.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h >> index 908b309..b8f51df 100644 >> --- a/kernel/rcu/tree_plugin.h >> +++ b/kernel/rcu/tree_plugin.h >> @@ -1493,7 +1493,7 @@ static void rcu_prepare_for_idle(void) >> rdtp->last_accelerate = jiffies; >> for_each_rcu_flavor(rsp) { >> rdp = this_cpu_ptr(rsp->rda); >> - if (rcu_segcblist_pend_cbs(&rdp->cblist)) >> + if (!rcu_segcblist_pend_cbs(&rdp->cblist)) >> continue; >> rnp = rdp->mynode; >> raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */ >> -- >> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a >> member of the Code Aurora Forum, hosted by The Linux Foundation >>
-- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation
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