From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751186AbdHBFpU (ORCPT ); Wed, 2 Aug 2017 01:45:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56106 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbdHBFpS (ORCPT ); Wed, 2 Aug 2017 01:45:18 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9070017FBFA Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=pbonzini@redhat.com Date: Wed, 2 Aug 2017 01:45:16 -0400 (EDT) From: Paolo Bonzini To: Eric Dumazet Cc: linux-kernel@vger.kernel.org, Peter Zijlstra Message-ID: <1879111268.746025.1501652716698.JavaMail.zimbra@redhat.com> In-Reply-To: <1501620734.25002.10.camel@edumazet-glaptop3.roam.corp.google.com> References: <1501601046-35683-1-git-send-email-pbonzini@redhat.com> <1501601046-35683-3-git-send-email-pbonzini@redhat.com> <1501620734.25002.10.camel@edumazet-glaptop3.roam.corp.google.com> Subject: Re: [PATCH 2/3] jump_labels: do not use unserialized static_key_enabled MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [94.39.192.75, 10.4.196.28, 10.4.195.6] Thread-Topic: jump_labels: do not use unserialized static_key_enabled Thread-Index: PAry8pJ4rjUvhnaPs+HhaAETEKVvyw== X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 02 Aug 2017 05:45:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- Original Message ----- > From: "Eric Dumazet" > To: "Paolo Bonzini" > Cc: linux-kernel@vger.kernel.org, "Peter Zijlstra" > Sent: Tuesday, August 1, 2017 10:52:14 PM > Subject: Re: [PATCH 2/3] jump_labels: do not use unserialized static_key_enabled > > On Tue, 2017-08-01 at 17:24 +0200, Paolo Bonzini wrote: > > Any use of key->enabled (that is static_key_enabled and static_key_count) > > outside jump_label_lock should handle its own serialization. The only > > two that are not doing so are the UDP encapsulation static keys. Change > > them to use static_key_enable, which now correctly tests key->enabled under > > the jump label lock. > > > > diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c > > index 1d6219bf2d6b..74b7810df9fc 100644 > > --- a/net/ipv4/udp.c > > +++ b/net/ipv4/udp.c > > @@ -1644,8 +1644,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, > > struct sk_buff *skb) > > static struct static_key udp_encap_needed __read_mostly; > > void udp_encap_enable(void) > > { > > - if (!static_key_enabled(&udp_encap_needed)) > > - static_key_slow_inc(&udp_encap_needed); > > + static_key_enable(&udp_encap_needed); > > } > > Looks good to me, but static_key_enable() is not serialized either ? > > I suspect you should have CCed me on patch 1/3 :) Yes, indeed... That's the "now correctly test" in the commit message. What a difference one word makes. :) You can find 1/3 at https://patchwork.kernel.org/patch/9874845/. Paolo