> On Thu, Oct 29, 2015 at 6:21 PM, Neal P. Murphy > <neal.p.murphy@xxxxxxxxxxxx> wrote: > > On Thu, 29 Oct 2015 17:01:24 -0700 > > Ani Sinha <ani@xxxxxxxxxx> wrote: > > > >> On Wed, Oct 28, 2015 at 11:40 PM, Neal P. Murphy > >> <neal.p.murphy@xxxxxxxxxxxx> wrote: > >> > 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. > >> > >> Should I resend the patch with a Tested-by: tag? > > > > ... Oh, wait. Not yet. The dawn just broke over ol' Marblehead here. I only tested TCP; I need to hammer UDP, too. > > > > Can I set the timeouts to zero? Or is one as low as I can go? > > Any progress with testing ? I applied the 'hammer' through a firewall with the patch. I used TCP, UDP and ICMP. I don't know if the patch fixes the problem. But I'm reasonably sure that it did not break normal operations. To test a different problem I fixed (a memory leak in my 64-bit counter patch for xt_ACCOUNT), I tested 60,000 addresses (most of a /16) through the firewall. Again, no troubles. I only observed two odd things which are likely completely unrelated to your patch. When I started the TCP test, then added the UDP test, only TCP would come through. If I stopped and restarted the TCP test, only UDP would come through. I suspect this is due to buffering. It's just a behaviour I haven't encountered since I started using Linux many years ago (around '98). The second, when I started the test, the firewall would lose contact with the upstream F/W's apcupsd daemon; again, this is likely due to the nature of the test: it likely floods input and output queues. I'd say you can probably resend with Tested-by. Neal -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
