CentOS 1000hz kernel help

[maggot]

I'm attempting to tweak my own kernel so that I can get 1000FPS in srcds on CentOS (the current kernel is limited to 333FPS). I've tried downloading a couple kernel sources off of kernel.org (2.6.31.1 and 2.6.32.2), and after successfully compiling, I always get an error something like "kernel panic: not syncing". I assume it's related to my initrd image, or some driver I've forgotten to include in my kernel.

Could anybody shed some light on what I'm doing wrong?

[rustydusty1717]

I'm using the base CentOS kernel that comes with a VPS and I can run my servers at 1000FPS fine. Maybe John can help you figure out why it's not working out.

[Edge100x]

It can say that error for a lot of reasons, including basic things like the disk not being specified properly in the kernel command line (or not having the right disk driver). I believe that Xen/Qemu emulates the Intel PIIX disk controller; could you check to make sure that you are including that?

Could you post a screenshot of what the console looks like with this message at the bottom?

[maggot]

I may give the Gentoo install a shot, but I have some troubles with it as well. It's only using one of my IP addresses (I have 3). If I decide to use it, I'll investigate adding support for the other IPs.

Below is a screenshot when I attempt to load my modified kernel.

[maggot]

Apologies for the double post. It appears that srcds is limited to 333FPS on 64-bit linux installs. Rusty, are you using a 32 bit install?

[Edge100x]

I may give the Gentoo install a shot, but I have some troubles with it as well. It's only using one of my IP addresses (I have 3). If I decide to use it, I'll investigate adding support for the other IPs.

With our autoinstall, it should assign all of your IPs automatically. Were you using the autoinstall? If so, did you see all your IPs in /etc/conf.d/net?

Below is a screenshot when I attempt to load my modified kernel.

It does sound like it's having problems loading something with the disk. Partly this could stem from the fact that CentOS is designed around 2.6.18 and may have old headers/support libs installed for this old version. Did you also compile in everything for your custom kernel, instead of including functions as modules? Were there any errors during the compilation process?

Apologies for the double post. It appears that srcds is limited to 333FPS on 64-bit linux installs. Rusty, are you using a 32 bit install?

The Gentoo autoinstall that I recommend is 64-bit and able to run 1000fps servers successfully, but you are right that it is possible that older kernels than it uses could behave differently. Linux used to separate the timer functions for 64-bit and 32-bit versions (and there was a time when select() did not use high resolution timers, but nanosleep() did -- but though that's not relevant to this case).

[rustydusty1717]

Apologies for the double post. It appears that srcds is limited to 333FPS on 64-bit linux installs. Rusty, are you using a 32 bit install?

Yes, I am using 32 bit CentOS. I'm also running CS1.6 server's, not source. I can get a steady 950+ fps on both of my servers though.

[maggot]

I may give the Gentoo install a shot, but I have some troubles with it as well. It's only using one of my IP addresses (I have 3). If I decide to use it, I'll investigate adding support for the other IPs.

With our autoinstall, it should assign all of your IPs automatically. Were you using the autoinstall? If so, did you see all your IPs in /etc/conf.d/net?

Below is a screenshot when I attempt to load my modified kernel.

It does sound like it's having problems loading something with the disk. Partly this could stem from the fact that CentOS is designed around 2.6.18 and may have old headers/support libs installed for this old version. Did you also compile in everything for your custom kernel, instead of including functions as modules? Were there any errors during the compilation process?
I tried to compile everything required for boot directly into the kernel, because I believe my problem stemmed from my initrd.img. I didn't see any errors in the compile, but there's quite a bit of content there.

Apologies for the double post. It appears that srcds is limited to 333FPS on 64-bit linux installs. Rusty, are you using a 32 bit install?

The Gentoo autoinstall that I recommend is 64-bit and able to run 1000fps servers successfully, but you are right that it is possible that older kernels than it uses could behave differently. Linux used to separate the timer functions for 64-bit and 32-bit versions (and there was a time when select() did not use high resolution timers, but nanosleep() did -- but though that's not relevant to this case).

The Gentoo install does indeed work properly in regards to FPS. I'm just having trouble with my other IP addresses. If I run "ifconfig", it only shows one of them. Another barrier holding me back is that I'm a bit rusty in regards to using Emerge, but it shouldn't be too big of a problem.

Apologies for the double post. It appears that srcds is limited to 333FPS on 64-bit linux installs. Rusty, are you using a 32 bit install?

Yes, I am using 32 bit CentOS. I'm also running CS1.6 server's, not source. I can get a steady 950+ fps on both of my servers though.

I'm not sure if that proves or disproves what I've seen in my Google-based research (considering you're using hlds, I'm using srcds), but I appreciate the response.

[Edge100x]

The Gentoo install does indeed work properly in regards to FPS. I'm just having trouble with my other IP addresses. If I run "ifconfig", it only shows one of them. Another barrier holding me back is that I'm a bit rusty in regards to using Emerge, but it shouldn't be too big of a problem.

"ifconfig" is actually deprecated and often does not show the correct information. The command I recommend using is "ip address". If it doesn't show all your IPs, or you don't see the IPs in /etc/conf.d/net, then I'd have to take a closer look at our autoinstaller and try to determine what it might be doing wrong.

[maggot]

I wasn't aware of "ip address". Pretty nifty :p Anyway, I see all of my IPs there and in the config, but only one reponds to pings. Is this normal?

[Edge100x]

I wasn't aware of "ip address". Pretty nifty :p Anyway, I see all of my IPs there and in the config, but only one reponds to pings. Is this normal?

They should all respond to pings, but if you just reinstalled, then you might be running into an issue with an old ARP cache entry on InterNAP's end. I'd recommend trying to ping a few other IPs on your subnet with commands like this -- it often resets the cache:

Code: Select all

ping w.x.y.253 -I w.x.y.z
ping w.x.y.254 -I w.x.y.z

Where w.x.y.z is the IP address that isn't responding to pings.

[maggot]

I wasn't aware of "ip address". Pretty nifty :p Anyway, I see all of my IPs there and in the config, but only one reponds to pings. Is this normal?

They should all respond to pings, but if you just reinstalled, then you might be running into an issue with an old ARP cache entry on InterNAP's end. I'd recommend trying to ping a few other IPs on your subnet with commands like this -- it often resets the cache:

Code: Select all

ping w.x.y.253 -I w.x.y.z
ping w.x.y.254 -I w.x.y.z

Where w.x.y.z is the IP address that isn't responding to pings.

That fixed it right up, I can ping those addresses now. I can SSH on them now as well Will I have to do this every reboot, or does this just fix something on Internap's networking side?

[Edge100x]

That fixed it right up, I can ping those addresses now. I can SSH on them now as well Will I have to do this every reboot, or does this just fix something on Internap's networking side?

This clears out the stored MAC address on their side and it's something that you'll only have to do once with this install. The MAC address changed when your OS was reinstalled, which is why it started occurring (they were still trying to send the traffic to your old MAC).

[maggot]

Ah, gotcha. Makes sense now :p I'm having trouble setting the "chrt" via GameCP, but it has a priority setting (which I assume uses nice). Is nice good enough, or is chrt preferred?

[Edge100x]

Setting the process to realtime is necessary to remove the timer slack (the kernel approximates timers more without it, leading to a fluctuating, lower FPS). "nice" doesn't accomplish this, so you'd need to chrt them by hand, or edit the control panel to do it.