On Mon, 4 Feb 2019 20:45:13 +0000 Mike Pumford <mpumf...@mudcovered.org.uk> wrote:
> On 03/02/2019 12:07, Sad Clouds wrote: > > On Sun, 3 Feb 2019 11:27:07 +0100 > > tlaro...@polynum.com wrote: > > > >> With all your help and from this summary, I suspect that the > >> probable culprit is 3) above (linked also to 2) but mainly 3): an > >> instance of Samba, serving a 10T or a 100T request is blocking on > >> I/O, > > > > You must have some ancient hardware that is not capable of utilising > > full network bandwidth. > > > > I have Sun Ultra10 with 440MHz CPU, this has a 1000baseT PCI network > > card, but when sending TCP data it can only manage around 13 > > MiB/sec. Looking at 'vmstat 1' output it is clear that CPU is 100% > > busy, 50% system + 50% interrupt. > > > > ultra10$ ifconfig wm0 > > wm0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 > > capabilities=2bf80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx> > > capabilities=2bf80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Tx> > > capabilities=2bf80<UDP6CSUM_Tx> > > enabled=0 > Any reason you aren't using the hardware offload capability of this > interface? The card supports checksum ofloading for v4 &v6 frames and > also the ofloading of some of the TCP stack work for V4 this might > help your performance. Loogking at this output I'd suggest adding the > following to your ifconfig.wm0 file: > tso4 ip4csum tcp4csum > > Not exactly sure on the options for the V6 stuff (check the ifconfig > man page). My wm card has more v6 offload so I don't think the v6 > options I use would work. > > I suspect the offload would give you more of a boost than on my > 2-4GHz amd64 systems but even on those its quit noticable the > difference that turning these on makes. > > Mike I've tried those options before, but performance gain was marginal compared to gigabit ethernet speeds, i.e. it went up from 13 MiB/sec to around 17 MiB/sec. But I guess 30% gain is better than nothing. I think Sun Ultra10 has 32-bit 33 MHz PCI bus, so in theory it has bandwidth for 133 MiB/sec. Not sure why there is such high CPU usage on this system when copying data via the network card. OK it's a very old system, but I was expecting less overhead.