Hello,
On Tue, 12 Nov 2013, Geert Uytterhoeven wrote:
> net/netfilter/ipvs/ip_vs_sync.c: In function 'sync_thread_master':
> net/netfilter/ipvs/ip_vs_sync.c:1640:8: warning: unused variable 'ret'
> [-Wunused-variable]
>
> Commit 35a2af94c7ce7130ca292c68b1d27fcfdb648f6b ("sched/wait: Make the
> __wait_event*() interface more friendly") changed how the interruption
> state is returned. However, sync_thread_master() ignores this state,
> now causing a compile warning.
>
> According to Julian Anastasov <j...@ssi.bg>, this behavior is OK:
>
> "Yes, your patch looks ok to me. In the past we used ssleep() but IPVS
> users were confused why IPVS threads increase the load average. So, we
> switched to _interruptible calls and later the socket polling was
> added."
>
> Document this, as requested by Peter Zijlstra, to avoid precious developers
> disappearing in this pitfall in the future.
>
> Signed-off-by: Geert Uytterhoeven <ge...@linux-m68k.org>
> ---
> v2: Document that sync_thread_master() ignores the interruption state,
>
> net/netfilter/ipvs/ip_vs_sync.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
> index f63c2388f38d..db801263ee9f 100644
> --- a/net/netfilter/ipvs/ip_vs_sync.c
> +++ b/net/netfilter/ipvs/ip_vs_sync.c
> @@ -1637,7 +1637,10 @@ static int sync_thread_master(void *data)
> continue;
> }
> while (ip_vs_send_sync_msg(tinfo->sock, sb->mesg) < 0) {
> - int ret = __wait_event_interruptible(*sk_sleep(sk),
> + /* (Ab)use interruptible sleep to avoid increasing
> + * the load avg.
> + */
> + __wait_event_interruptible(*sk_sleep(sk),
> sock_writeable(sk) ||
> kthread_should_stop());
> if (unlikely(kthread_should_stop()))
Fabio Estevam posted similar change too early but
we are better with such comment.
Acked-by: Julian Anastasov <j...@ssi.bg>
Also, the TASK_UNINTERRUPTIBLE | TASK_IDLE idea looks good
to me. If such change is planned may be the above patch
better not to go via the ipvs-next tree to avoid conflicts?
As we don't have any changes in this area let us know if
someone takes the above patch for another tree.
Regards
--
Julian Anastasov <j...@ssi.bg>
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