Messages in this thread | | | From | "George Bonser" <> | Subject | RE: [PATCH] 2.4.6-pre2 page_launder() improvements | Date | Sun, 10 Jun 2001 01:38:01 -0700 |
| |
> > This patch has given excellent results on my laptop and my > workstation here and seems to improve kernel behaviour in tests > quite a bit. I can play mp3's unbuffered during moderate write > loads or moderately heavy IO ;) > > YMMV, please test it. If it works great for everybody I'd like > to get this improvement merged into the next -pre kernel.
For the test I ran it through, it was about the same as 2.4.6-pre2 vanilla.
The test I did can be simulated easilly enough. Apache with keepalives off. about 50 connections/second pulling a 10K file. Have half a gig of swap. Told the machine on boot that it had 64MB of RAM. Prestarted 250 apache children. Once everything settles down, I was about 10meg into swap and everything is running smoothly. So far so good. Now I figured I would push it a little more into swap so this being a production server, I can't really tell the world to make more connections so I do the next best thing and turn keepalives on with a timeout of 2 seconds figuring this would increase the number of apache children alive and push me deeper into swap. Restarted apache and within about 5 seconds the machine stopped responding to console input. top would not update the screen but the machine would respond to pings.
I took it out of the load balancer and regained control in seconds. The 15 minute load average showed somewhere over 150 with a bazillion apache processes. Even top -q would not update when I put it back into the balancer. The load average and number of processes started to increase until I got to some point where it would just stop providing output. Again, control returned within seconds after taking it out of the balancer. As far as I could tell, I never at any time got more than 100MB into swap.
Your patch did seem to keep the machine alive a little longer but that is subjective and I have no data to back that statement up. Vanilla 2.4.6-pre2 seemed to die off a little faster. Again, with both kernels, pings were fine, just no interactive at all. I was logged in over the net with no console so I could not see what was hogging the CPU bot it did not appear to be a user process. That top -q would not update tells me it was likely in the kernel because that runs as the highest priority user process. I just could not get any CPU in user space.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |