From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Subject: Re: [Patch net 1/2] act_ife: only acquire tcf_lock for existing actions Date: Thu, 23 Jun 2016 07:10:29 -0400 Message-ID: <576BC3A5.3070509@mojatatu.com> References: <1466455039-23268-1-git-send-email-xiyou.wangcong@gmail.com> <1466455039-23268-2-git-send-email-xiyou.wangcong@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: khoroshilov@ispras.ru To: Cong Wang , netdev@vger.kernel.org Return-path: Received: from mail-qk0-f194.google.com ([209.85.220.194]:36833 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751662AbcFWLKb (ORCPT ); Thu, 23 Jun 2016 07:10:31 -0400 Received: by mail-qk0-f194.google.com with SMTP id l81so15289983qke.3 for ; Thu, 23 Jun 2016 04:10:30 -0700 (PDT) In-Reply-To: <1466455039-23268-2-git-send-email-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 16-06-20 04:37 PM, Cong Wang wrote: > Alexey reported that we have GFP_KERNEL allocation when > holding the spinlock tcf_lock. Actually we don't have > to take that spinlock for all the cases, especially > for the new one we just create. To modify the existing > actions, we still need this spinlock to make sure > the whole update is atomic. > > For net-next, we can get rid of this spinlock because > we already hold the RTNL lock on slow path, and on fast > path we can use RCU to protect the metalist. > > Joint work with Jamal. > > Reported-by: Alexey Khoroshilov > Cc: Jamal Hadi Salim > Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim cheers, jamal