From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net-next] net: rps: Add the rfs_needed check when record flow hash Date: Thu, 25 May 2017 07:55:03 -0700 Message-ID: <1495724103.6465.98.camel@edumazet-glaptop3.roam.corp.google.com> References: <1495611359-118199-1-git-send-email-gfree.wind@vip.163.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org To: gfree.wind@vip.163.com Return-path: Received: from mail-pf0-f193.google.com ([209.85.192.193]:35168 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757320AbdEYOzH (ORCPT ); Thu, 25 May 2017 10:55:07 -0400 Received: by mail-pf0-f193.google.com with SMTP id u26so39786100pfd.2 for ; Thu, 25 May 2017 07:55:07 -0700 (PDT) In-Reply-To: <1495611359-118199-1-git-send-email-gfree.wind@vip.163.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2017-05-24 at 15:35 +0800, gfree.wind@vip.163.com wrote: > From: Gao Feng > > There are two spots which invoke the sock_rps_record_flow_hash, one is > sock_rps_record_flow which has already checked rfs_needed. But the other > is tun_flow_update which doesn't check if the rfs is enabled. > > Now rename the original function sock_rps_record_flow_hash to > _sock_rps_record_flow_hash, and add one helper func which checks the > rfs_needed. > > The perf result of two functions is following. > When rfs is disabled, it could enhance 58% performance with checking > rfs_needed. > When rfs is enabled, the performanc is lower than current about 29%. > > Because the RFS is disabled by default. I think it is useful to tun > driver. > > The follow is test statistics. > Signed-off-by: Gao Feng > --- > include/net/sock.h | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/include/net/sock.h b/include/net/sock.h > index 3467d9e..584bb9a 100644 > --- a/include/net/sock.h > +++ b/include/net/sock.h > @@ -910,7 +910,7 @@ static inline void sk_incoming_cpu_update(struct sock *sk) > sk->sk_incoming_cpu = raw_smp_processor_id(); > } > > -static inline void sock_rps_record_flow_hash(__u32 hash) > +static inline void _sock_rps_record_flow_hash(__u32 hash) > { > #ifdef CONFIG_RPS > struct rps_sock_flow_table *sock_flow_table; > @@ -922,6 +922,14 @@ static inline void sock_rps_record_flow_hash(__u32 hash) > #endif > } > > +static inline void sock_rps_record_flow_hash(__u32 hash) > +{ > +#ifdef CONFIG_RPS > + if (static_key_false(&rfs_needed)) > + _sock_rps_record_flow_hash(hash); > +#endif Seems that after your patch, sock_rps_record_flow_hash() is no longer needed/used.