Re: [PATCH 1/2] sched: Add cond_resched_rcu_lock() helper

From: Ingo Molnar
Date: Fri Apr 26 2013 - 02:14:13 EST



* Simon Horman <horms@xxxxxxxxxxxx> 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().
>
> As suggested by Eric Dumazet.
>
> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> Cc: Julian Anastasov <ja@xxxxxx>
> Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
> ---
> include/linux/sched.h | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index e692a02..7eec4c7 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -2787,3 +2787,12 @@ static inline unsigned long rlimit_max(unsigned int limit)
> }
>
> #endif
> +
> +static void inline cond_resched_rcu_lock(void)
> +{
> + if (need_resched()) {
> + rcu_read_unlock();
> + cond_resched();
> + rcu_read_lock();
> + }
> +}

Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>

Ingo
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