From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: netlink: Disable insertions/removals during rehash Date: Thu, 4 Jun 2015 09:27:27 -0700 Message-ID: <20150604162727.GA2670@roeck-us.net> References: <20150514055824.GB6058@gondor.apana.org.au> <20150515.130257.1322224469755323983.davem@redhat.com> <20150516131628.GA981@gondor.apana.org.au> <20150516.171019.1206903516753105739.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: herbert@gondor.apana.org.au, eric.dumazet@gmail.com, tgraf@suug.ch, netdev@vger.kernel.org To: David Miller Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:57448 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752341AbbFDQ1c (ORCPT ); Thu, 4 Jun 2015 12:27:32 -0400 Content-Disposition: inline In-Reply-To: <20150516.171019.1206903516753105739.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, May 16, 2015 at 05:10:19PM -0400, David Miller wrote: > From: Herbert Xu > Date: Sat, 16 May 2015 21:16:28 +0800 > > > On Fri, May 15, 2015 at 01:02:57PM -0400, David Miller wrote: > >> From: Herbert Xu > >> Date: Thu, 14 May 2015 13:58:24 +0800 > >> > >> > The current rhashtable rehash code is buggy and can't deal with > >> > parallel insertions/removals without corrupting the hash table. > >> > > >> > This patch disables it by partially reverting > >> > c5adde9468b0714a051eac7f9666f23eb10b61f7 ("netlink: eliminate > >> > nl_sk_hash_lock"). > >> > > >> > This patch also removes a bogus socket lock introduced by that > >> > very same patch. > >> > > >> > Signed-off-by: Herbert Xu > >> > >> Herbert, if you agree with me in the other thread that the lock_sock() > >> or something like it has to remain, you'll need to respin this. > > > > Actually I think this one is OK because I'm replacing it with the > > hash table mutex which is just like the previous global lock except > > that it is per-family. As you cannot change the family on a netlink > > socket this should be good enough. > > > > But the changelog message is wrong so here is an updated version. > > > > Cheers, > > > > ---8<--- > > The current rhashtable rehash code is buggy and can't deal with > > parallel insertions/removals without corrupting the hash table. > > > > This patch disables it by partially reverting > > c5adde9468b0714a051eac7f9666f23eb10b61f7 ("netlink: eliminate > > nl_sk_hash_lock"). > > > > Signed-off-by: Herbert Xu > > Ok, I've queued this up for -stable, thanks Herbert. > Hi David, sorry for bothering you - I don't see this patch in any of your trees, and it is marked as "changes requested" in patchwork. Did I look at the wrong places, do you still plan to apply the patch as-is, or do you expect some changes ? As side info, I have been trying to track down the getaddrinfo hang problem observed by others, which we see in 3.19.4 and 4.0.4. Thanks, Guenter