On Wed, 28 Oct 2015 02:36:50 -0400 "Neal P. Murphy" <neal.p.murphy@xxxxxxxxxxxx> wrote: > On Mon, 26 Oct 2015 21:06:33 +0100 > Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx. > > > > 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. N -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
