From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ani Sinha Subject: Re: [PATCH 1/1] commit c6825c0976fa7893692e0e43b09740b419b23c09 upstream. Date: Thu, 29 Oct 2015 17:01:24 -0700 Message-ID: References: <20151026200633.GA13476@salvia> <17709_1446014232_t9S6b5a3017652_20151028023650.7b76098f@playground> <20151029024052.28e11c83@playground> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Cc: Pablo Neira Ayuso , netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, "netdev@vger.kernel.org" To: "Neal P. Murphy" Return-path: In-Reply-To: <20151029024052.28e11c83@playground> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Oct 28, 2015 at 11:40 PM, Neal P. Murphy wrote: > On Wed, 28 Oct 2015 02:36:50 -0400 > "Neal P. Murphy" wrote: > >> On Mon, 26 Oct 2015 21:06:33 +0100 >> Pablo Neira Ayuso wrote: >> >> > Hi, >> > >> > On Mon, Oct 26, 2015 at 11:55:39AM -0700, Ani Sinha wrote: >> > > netfilter: nf_conntrack: fix RCU race in nf_conntrack_find_get >> > >> > Please, no need to Cc everyone here. Please, submit your Netfilter >> > patches to netfilter-devel@vger.kernel.org. >> > >> > Moreover, it would be great if the subject includes something >> > descriptive on what you need, for this I'd suggest: >> > >> > [PATCH -stable 3.4,backport] netfilter: nf_conntrack: fix RCU race in nf_conntrack_find_get >> > >> > I'm including Neal P. Murphy, he said he would help testing these >> > backports, getting a Tested-by: tag usually speeds up things too. >> > > I've probably done about as much seat-of-the-pants testing as I can. All opening/closing the same destination IP/port. > > Host: Debian Jessie, 8-core Vishera 8350 at 4.4 GHz, 16GiB RAM at (I think) 2100MHz. > > Traffic generator 1: 6-CPU KVM running 64-bit Smoothwall Express 3.1 (linux 3.4.109 without these patches), with 8GiB RAM and 9GiB swap. Packets sent across PURPLE (to bypass NAT and firewall). > > Traffic generator 2: 32-bit KVM running Smoothwall Express 3.1 (linux 3.4.110 with these patches), 3GiB RAM and minimal swap. > > In the first set of tests, generator 1's traffic passed through Generator 2 as a NATting firewall, to the host's web server. In the second set of tests, generator 2's traffic went through NAT to the host's web server. > > The load tests: > - 2500 processes using 2500 addresses and random src ports > - 2500 processes using 2500 addresses and the same src port > - 2500 processes using the same src address and port > > I also tested using stock NF timeouts and using 1 second timeouts. > > Bandwidth used got as high as 16Mb/s for some tests. > > Conntracks got up to 200 000 or so or bounced between 1 and 2, depending on the test and the timeouts. > > I did not reproduce the problem these patches solve. But more importantly, I saw no problems at all. Each time I terminated a test, RAM usage returned to about that of post-boot; so there were no apparent memory leaks. No kernel messages and no netfilter messages appeared during the tests. > > If I have time, I suppose I could run another set of tests: 2500 source processes using 2500 addresses times 200 ports to connect to 2500 addresses times 200 ports on a destination system. Each process opens 200 sockets, then closes them. And repeats ad infinitum. But I might have to be clever since I can't run 500 000 processes; but I could run 20 VMs; that would get it down to about 12 000 processes per VM. And I might have to figure out how to allow allow processes on the destination system to open hundreds or thousands of sockets. Should I resend the patch with a Tested-by: tag?