Messages in this thread | | | Date | Tue, 30 Apr 2013 10:12:38 +0300 (EEST) | From | Julian Anastasov <> | Subject | Re: [PATCH v2 1/2] sched: Add cond_resched_rcu_lock() helper |
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Hello,
On Tue, 30 Apr 2013, Simon Horman wrote:
> This is intended for use in loops which read data protected by RCU and may > have a large number of iterations. Such an example is dumping the list of > connections known to IPVS: ip_vs_conn_array() and ip_vs_conn_seq_next(). > > The call to cond_resched() is guarded by #ifndef CONFIG_PREEMPT_RCU as in > the case of CONFIG_PREEMPT_RCU _rcu_read_unlock() will check to see if the > RCU core needs to be informed, so there is no need to invoke cond_resched() > in that case. Thanks to Paul E. McKenney for explaining this. > > cond_resched_rcu_lock() suggested by Eric Dumazet. > ifndef guard suggested by Paul E. McKenney and Julian Anastasov. > > Cc: Eric Dumazet <eric.dumazet@gmail.com> > Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Cc: Julian Anastasov <ja@ssi.bg> > Acked-by: Ingo Molnar <mingo@kernel.org> > Signed-off-by: Simon Horman <horms@verge.net.au> > > --- > > v2 > * Add guard the call to cond_resched() > --- > include/linux/sched.h | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index e692a02..66da71c 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -2787,3 +2787,14 @@ static inline unsigned long rlimit_max(unsigned int limit) > } > > #endif > + > +static void inline cond_resched_rcu_lock(void) > +{ > + if (need_resched()) {
Ops, it should be without above need_resched.
> + rcu_read_unlock(); > +#ifndef CONFIG_PREEMPT_RCU > + cond_resched(); > +#endif > + rcu_read_lock(); > + } > +} > -- > 1.8.2.1
Regards
-- Julian Anastasov <ja@ssi.bg>
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