Messages in this thread | | | Date | Thu, 10 Mar 2005 20:06:17 +0100 | From | Christian Schmid <> | Subject | Re: BUG: Slowdown on 3000 socket-machines tracked down |
| |
Attached an image here so you can see whats happening. One pixel are 2 seconds. You can see a small speed-up before the slow-down. This is where I changed lower_zone_protection from 1024 to 0. So it seems its speeding up until the memory is full. Then it drastically slows-down until I set it to 1024 again. then it goes up slowly but not linear (interesting smoothly) until it peaks again at 82 MB/Sec.
PS: 82 MB/sec is not our bandwidth-limit. It still peaks there. Dont know why. Certainly not the drives. They work up to 200 MB/Sec (10 drives there).
Chris
Andrew Morton wrote: > Christian Schmid <webmaster@rapidforum.com> wrote: > >> > So, maybe a VM problem? That would be a good place to focus since >> > I think we can be fairly certain it isn't a problem in just the >> > networking code. Otherwise, my tests would show lower bandwidth. >> >> Thanks to your tests I am really sure that its no network-code problem anymore. But what I THINK it >> is: The network is allocating buffers dynamically and if the vm doesnt provide that buffers fast >> enough, it locks as well. > > > Did anyone have a 100-liner which demonstrates this problem? > > The output of `vmstat 1' when the thing starts happening would be interesting. > > [image] | |