ULE scheduler and the WCPU column in top
I have this interesting behavior in the top utility on _both_ my 7.1 and 8.0 FreeBSD servers (updated to latest patches). The interesting behavior happens only when my kernel is compiled with the ULE scheduler. It does not happen when the kernel uses the old BSD scheduler. Here is a link of a screenshot of top on one of my servers: http://daffy.nerius.com/temp/top.png The output of top usually looks just like this, at most times of the day. The row that worries me is the process ioUrTded.i3 run by the user urt1, which is reported to be using 1.17% WCPU in the screenshot. It's the sixth row down. The thing that makes no sense is that this process is in fact using more CPU than any other process on my system, and I know this as a fact. The processes that are most active are all video game servers, and the game server run by the urt1 user is the most populated with the most going on, by far. With my kernel compiled to use the old BSD scheduler, the process run by urt1 is _always_ the most active as reported by top; the WCPU shows between 30 and 40 percent on this process normally (with the BSD scheduler). The WCPU percentage on the process owned by urt1 never reaches very high - it always stays abnormally low as reported by top (with the ULE scheduler). The process itself is running just fine and the game server is very busy. Any ideas? Is this a known issue when running the ULE scheduler? Any negative impacts that might occur? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
ULE scheduler
have a stock 7.0 release. I rebuilt the kernel with ULE scheduler, I think. How can I tell if it is running ULE or 4BSD?? David R. Stegner ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: ULE scheduler
On Fri, 10 Apr 2009 15:17:28 -0700, Dave Stegner dsteg...@earthlink.net wrote: I rebuilt the kernel with ULE scheduler, I think. How can I tell if it is running ULE or 4BSD?? I think that's what you're looking for: % sysctl kern.sched.name kern.sched.name: ULE -- Polytropon From Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
ULE Scheduler and overall performance on 6.x - Wow
Hi, I decided to give the ULE scheduler a try a while ago (April 28). when I last built 6-STABLE Anyhow it seems great. I'm running a 2.4GHz Celeron with 512MB RAM and two 40GB, PATA disks. Right now I'm running both a GNOME and a KDE session, I've got Thunderbird and Evolution open, Firefox is running and running well, and I'm updating the my local copy of the FreeBSD repository. Oh yeah, I'm also running a DNS server, a Sendmail server, and SAMBA I can't believe how responsive everything is on this low-end machine I'm running.Wow! (And this with debugging turned on but no WITNESS or INVARIANTS turned on) Well time to rebuild the sources :) dwpc@ /home/duaneuname -a FreeBSD dwpc.dwlabs.ca 6.1-RC FreeBSD 6.1-RC #0: Fri Apr 28 18:41:15 ADT 2006 [EMAIL PROTECTED]:/usr/obj/usr/src/sys/DWPC-KERNEL i386 Best Regards, Duane Whitty -- [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: ULE Scheduler and overall performance on 6.x - Wow
i remember when i first started using freebsd about 2 months ago, the first kernel i built, i did the ULE (at some articles recommendataion). but, ive not done it since. i guess i have been noticing a bit of lag on my system (amd 1800mhz 512rdram, u160 scsi raid0), but nothing unacceptable. however, since i didnt have a problem with my first kernel that i did, and your positive response, i decided to go ahead and change out the specified scheduler in my kernconf, and let 'er rip. is your system a desktop? were your prevously running the same desktop configuration on the same box, with the 4BSD? is the ULE scheduler suited for a server setup as well (my server is also SMP), or is this something that should be kept to a desktop? thanks, jonathan horne On Sunday 07 May 2006 04:43, Duane Whitty wrote: Hi, I decided to give the ULE scheduler a try a while ago (April 28). when I last built 6-STABLE Anyhow it seems great. I'm running a 2.4GHz Celeron with 512MB RAM and two 40GB, PATA disks. Right now I'm running both a GNOME and a KDE session, I've got Thunderbird and Evolution open, Firefox is running and running well, and I'm updating the my local copy of the FreeBSD repository. Oh yeah, I'm also running a DNS server, a Sendmail server, and SAMBA I can't believe how responsive everything is on this low-end machine I'm running.Wow! (And this with debugging turned on but no WITNESS or INVARIANTS turned on) Well time to rebuild the sources :) dwpc@ /home/duaneuname -a FreeBSD dwpc.dwlabs.ca 6.1-RC FreeBSD 6.1-RC #0: Fri Apr 28 18:41:15 ADT 2006 [EMAIL PROTECTED]:/usr/obj/usr/src/sys/DWPC-KERNEL i386 Best Regards, Duane Whitty ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: ULE Scheduler and overall performance on 6.x - Wow
On Sun, May 07, 2006 at 06:43:14AM -0300, Duane Whitty wrote: Hi, I decided to give the ULE scheduler a try a while ago (April 28). when I last built 6-STABLE Anyhow it seems great. I'm running a 2.4GHz Celeron with 512MB RAM and two 40GB, PATA disks. Right now I'm running both a GNOME and a KDE session, I've got Thunderbird and Evolution open, Firefox is running and running well, and I'm updating the my local copy of the FreeBSD repository. Oh yeah, I'm also running a DNS server, a Sendmail server, and SAMBA I can't believe how responsive everything is on this low-end machine I'm running.Wow! (And this with debugging turned on but no WITNESS or INVARIANTS turned on) FYI, in my testing ULE is faster under light workloads but quite a lot slower under heavy loads. It's not recommended, but YMMV. Kris pgppGBKH0ZlRx.pgp Description: PGP signature
Re: ULE Scheduler and overall performance on 6.x - Wow
Jonathan Horne wrote: i remember when i first started using freebsd about 2 months ago, the first kernel i built, i did the ULE (at some articles recommendataion). but, ive not done it since. i guess i have been noticing a bit of lag on my system (amd 1800mhz 512rdram, u160 scsi raid0), but nothing unacceptable. however, since i didnt have a problem with my first kernel that i did, and your positive response, i decided to go ahead and change out the specified scheduler in my kernconf, and let 'er rip. is your system a desktop? were your prevously running the same desktop configuration on the same box, with the 4BSD? is the ULE scheduler suited for a server setup as well (my server is also SMP), or is this something that should be kept to a desktop? thanks, jonathan horne My system is a desktop and yes I was previously using the 4BSD scheduler. As for whether it is suited for a server environment I would say that depends. From what I understand it is an experimental scheduler meant to bring better performance to SMP machines but that UP machines may also show some improvement. If I was using this box as a server for mission critical applications there are a whole bunch of things I am doing now that I would not be doing. Before I would use any relatively new configuration on a production server I would have to do some reliability testing and benchmarking on a test machine that I had configured to test a particular harware/application mix. I would also be reading what other people had to say and I would first choose to use something that was known to generally work and for which issues were generally know and mostly understood. Also, go where the support is. :) This is basically a test box and a learning platform. There are way too many applications loaded on this machine and they are far too varied in nature for me to single out one aspect of my configuration and say whether or not it is suitable in a server configuration. In addition I wouldn't be able to say whether ULE is suitable for a server after testing it on hardware that is definitely not suitable as a server, in my opinion. I am willing to say that for desktop use the ULE scheduler --seems-- to work great. But do keep in mind Mr. Kennaway's comments per this thread. Of course the 4BSD scheduler works great so I wouldn't switch unless I had a reason to. --Duane On Sunday 07 May 2006 04:43, Duane Whitty wrote: Hi, I decided to give the ULE scheduler a try a while ago (April 28). when I last built 6-STABLE Anyhow it seems great. I'm running a 2.4GHz Celeron with 512MB RAM and two 40GB, PATA disks. Right now I'm running both a GNOME and a KDE session, I've got Thunderbird and Evolution open, Firefox is running and running well, and I'm updating the my local copy of the FreeBSD repository. Oh yeah, I'm also running a DNS server, a Sendmail server, and SAMBA I can't believe how responsive everything is on this low-end machine I'm running.Wow! (And this with debugging turned on but no WITNESS or INVARIANTS turned on) Well time to rebuild the sources :) dwpc@ /home/duaneuname -a FreeBSD dwpc.dwlabs.ca 6.1-RC FreeBSD 6.1-RC #0: Fri Apr 28 18:41:15 ADT 2006 [EMAIL PROTECTED]:/usr/obj/usr/src/sys/DWPC-KERNEL i386 Best Regards, Duane Whitty ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: CPU affinity in new ULE scheduler
On Wed, 9 Nov 2005, Ian Lord wrote: Are you saying that ULE is slower then 4BSD ? I'm new to this and when I compiled my kernel, it was clear ULE was a better alternative for performance then 4BSD Schedulers are one of the hardest things to do right in OS design, as they rely a great deal on how workloads behave and interact. I've seen significantly varied performance between the two -- there are a lot of anecdotal reports that ULE is better for interactive workloads on a busy desktop machine, but keep in mind that 4BSD has seen a number of improvements in the last few years also. Right now, 4BSD is considered the production scheduler for FreeBSD, although there's continuing interest in improving ULE, as well as integrating some of the techniques used in ULE into 4BSD. For example, ULE used to see a significant performance win over 4BSD on SMP as it did a better job of identifying idle CPUs and migrating work to those CPUs. 4BSD has improved a lot on this front in the last year or two, and so has caught up with some of those benefits. In the end, only by measuring will you be able to tell if ULE is better for your workload. Measurement can mean qualitative experience (everything seems snappier) or quantitative (I get 14% more transactions per second with scheduler X). Robert N M Watson Thanks At 19:05 2005-11-09, Kris Kennaway wrote: On Wed, Nov 09, 2005 at 04:16:31PM -0600, Jon Brisbin wrote: I can't find any information on how to set the CPU affinity for processes in the FreeBSD 6 ULE scheduler. That's because you can't. ULE gives lower performance on the workloads I have tested anyway. This may be fixed in the future. Kris ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
CPU affinity in new ULE scheduler
I can't find any information on how to set the CPU affinity for processes in the FreeBSD 6 ULE scheduler. On the linux box, which we're moving from, I have dual Xeon HTT's that I have JBoss scheduled round-robin with the CPU affinity set to the first two processors, nice -15. I have Postgres scheduled SCHED_FIFO on the last two processors, nice -15. This gives me the greatest bandwidth possible in our scenario as it eliminates the CPU contention I had noticed before doing it this way. How do I do the same thing in FreeBSD? I have found a lot of information that talks about setting CPU affinity, but I have yet to find one example of how to do this. On linux, I'm using a CK-patched kernel and schedtool Is there something similar on FreeBSD? Thanks! Jon Brisbin Webmaster NPC International, Inc. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: CPU affinity in new ULE scheduler
On Wed, Nov 09, 2005 at 04:16:31PM -0600, Jon Brisbin wrote: I can't find any information on how to set the CPU affinity for processes in the FreeBSD 6 ULE scheduler. That's because you can't. ULE gives lower performance on the workloads I have tested anyway. This may be fixed in the future. Kris pgpo1zlUcDBeK.pgp Description: PGP signature
Re: CPU affinity in new ULE scheduler
Are you saying that ULE is slower then 4BSD ? I'm new to this and when I compiled my kernel, it was clear ULE was a better alternative for performance then 4BSD Thanks At 19:05 2005-11-09, Kris Kennaway wrote: On Wed, Nov 09, 2005 at 04:16:31PM -0600, Jon Brisbin wrote: I can't find any information on how to set the CPU affinity for processes in the FreeBSD 6 ULE scheduler. That's because you can't. ULE gives lower performance on the workloads I have tested anyway. This may be fixed in the future. Kris ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: CPU affinity in new ULE scheduler
On Wed, Nov 09, 2005 at 07:08:12PM -0500, Ian Lord wrote: Are you saying that ULE is slower then 4BSD ? I'm new to this and when I compiled my kernel, it was clear ULE was a better alternative for performance then 4BSD Yes, in the workloads I have tested. Others have reported similar things. You should carefully measure it yourself on your workloads to verify which is better. Kris pgp66BefrOC6Z.pgp Description: PGP signature
Re: Trouble with ULE scheduler
musikcom wrote: Hello! I have some trouble with ULE scheduler. I have installed FreeBSD 5.3 When I try to use ULE scheduler (by editing GENERIC file), the message The SCHED_ULE scheduler is broken. Please use SCHED_4BSD message appear. I do these steps: cd /sys/i386/confOK edit GENERICOK config GENERICOK cd ../compile/GENERICOK make dependFAILURE I send copy of GENERIC, sched_ule.c files in attachment and also file out.txt Please, help!!! - http://mobile.ngs.ru/games - Java- ... http://love.ngs.ru - [attached files removed to save bandwidth] The ULE scheduler was for all practical purposes disabled in 5.3 because of instability problems some people noticed with it - so the developers are working on fixing those bugs. In the meantime, you should continue to use SCHED_4BSD. -- Alan Gerber ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Trouble with ULE scheduler
On Fri, Dec 17, 2004 at 05:50:21PM +0600, musikcom wrote: Hello! I have some trouble with ULE scheduler. I have installed FreeBSD 5.3 When I try to use ULE scheduler (by editing GENERIC file), the message The SCHED_ULE scheduler is broken. Please use SCHED_4BSD message appear. You get that message because the ULE scheduler *is* broken. Please use the 4BSD scheduler instead. (And read the errata available at http://www.freebsd.org/releases/5.3R/errata.html ) -- Insert your favourite quote here. Erik Trulsson [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Trouble with ULE scheduler
Peter Farmer schrieb: From http://www.freebsd.org/releases/5.3R/errata.html (1 Nov 2004) The ULE scheduler described in the release notes has been completely disabled to discourage its use because it has stability problems. HTH Is there a way to explicitely enable it for testing purposes? Oliver ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Trouble with ULE scheduler
O. Hartmann wrote: Peter Farmer schrieb: From http://www.freebsd.org/releases/5.3R/errata.html (1 Nov 2004) The ULE scheduler described in the release notes has been completely disabled to discourage its use because it has stability problems. HTH Is there a way to explicitely enable it for testing purposes? the error message which the op attached to his email shows that the error is raised by an #error directive in sched_ule.c -- removing that line /might/ make ule build. regards, phil. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Trouble with ULE scheduler
On Fri, Dec 17, 2004 at 04:46:20PM +0100, O. Hartmann wrote: Peter Farmer schrieb: From http://www.freebsd.org/releases/5.3R/errata.html (1 Nov 2004) The ULE scheduler described in the release notes has been completely disabled to discourage its use because it has stability problems. HTH Is there a way to explicitely enable it for testing purposes? Yes, but all you'll find is that - yes - it's broken. *surprise*! Kris pgpYWyhsFQJ3r.pgp Description: PGP signature
