Message boards :
Number crunching :
Bad thread priority
Message board moderation
Author | Message |
---|---|
Send message Joined: 14 Jul 05 Posts: 275 Credit: 49,291 RAC: 0 |
I got an LHC workunit running, and my system started going sluggish. I noticed the LHC app had one thread running on Idle priority (probably the one doing the actual work), one on High, and one on Realtime. But there is one priority even lower than Idle, called Lowest! I set it to Lowest using a 3rd party program and my computer stopped being sluggish. You should REALLY recompile the LHC app with the latest BOINC API (it's currently using a version from year 2005). |
Send message Joined: 1 Dec 06 Posts: 13 Credit: 765,437 RAC: 0 |
But there is one priority even lower than Idle, called Lowest! I set it to Lowest using a 3rd party program and my computer stopped being sluggish. This doesn't make sense to me. First, Idle is most certainly the lowest priority class, and thread priority. You can read up on them here: http://msdn2.microsoft.com/en-us/library/ms685100.aspx Second, ProcessExplorer shows SixTrack in the Idle priority class, and the worker thread as having a priority of 2, and as you can see from the table in the above link, that means Idle class + Lowest thread priority. If you can reproduce this, dowload ProcessExplorer and check out the priority of the worker thread. I'm guessing a third party is messing things up though. |
Send message Joined: 18 Sep 04 Posts: 47 Credit: 1,886,234 RAC: 0 |
"Sluggish" could also be due to more than the thread priority - for example, page faults. What's your memory usage look like? |
Send message Joined: 14 Jul 05 Posts: 275 Credit: 49,291 RAC: 0 |
"Sluggish" could also be due to more than the thread priority - for example, page faults. What's your memory usage look like? I have had this problem with other projects, and I I'm absolutely sure it got working right after I manually changed the priority. |
Send message Joined: 14 Jul 05 Posts: 275 Credit: 49,291 RAC: 0 |
But there is one priority even lower than Idle, called Lowest! I set it to Lowest using a 3rd party program and my computer stopped being sluggish. SetPriority v0.2 by: Jeff Gilchrist http://gilchrist.ca/jeff/ Usage: setpriority [-g] [-p#] [-t#] [-lowest] <PID> -g : get process information only then exit -h : this help screen -p# : where # is new process priority class (default: 64 [IDLE]) -t# : where # is new thread priority (default: -15 [Lowest]) -lowest : sets lowest possible priority Example: setpriority -p32 -t-2 342 setpriority -lowest 342 setpriority -g 342 Process Thread ------- ------ RealTime : 256 15 High : 128 2 AboveNormal: 32768 1 Normal : 32 0 BelowNormal: 16384 -1 Idle : 64 -2 Lowest : N/A -15 LHC had one thread on priority 15, another on 2, another on -2 (if I remember correctly). Changed all threads to -15 and no more computer lag. (SetPriority doesn't let me change priority of individual threads) Maybe this app got Lowest and Idle names swapped, but there you can see the numbers... It was -2, should be -15. |
Send message Joined: 1 Dec 06 Posts: 13 Credit: 765,437 RAC: 0 |
LHC had one thread on priority 15, another on 2, another on -2 (if I remember correctly). Changed all threads to -15 and no more computer lag. (SetPriority doesn't let me change priority of individual threads) Maybe this app got Lowest and Idle names swapped, but there you can see the numbers... It was -2, should be -15. The terminology used by that program does not correspond to the terminology used by MS. It seems like "lowest" actually means THREAD_PRIORITY_IDLE. In which case it's 1 step down from what it currently uses (IDLE_PRIORITY_CLASS + THREAD_PRIORITY_LOWEST). If that really makes such a difference, my money is on a third party application/driver/voodoo. |
Send message Joined: 18 Sep 04 Posts: 47 Credit: 1,886,234 RAC: 0 |
"Sluggish" could also be due to more than the thread priority - for example, page faults. What's your memory usage look like? Do you know the tool you're using is giving you the right information? (I REALLY doubt that any BOINC related thread is running at "realtime" under windows) Do you understand what changing the priority really means to your whole system? Why are you the only one having this problem with LHC and other projects? Sounds like there's something weird with your system, and you're just using a bandaid..... Just my opinion |
Send message Joined: 14 Jul 05 Posts: 275 Credit: 49,291 RAC: 0 |
Many people had similar problems on BURP, the admin fixed the wrapper to set the correct thread priority to the worker app and everybody's problems went away. http://burp.boinc.dk/forum_thread.php?id=677 |
Send message Joined: 15 Oct 05 Posts: 43 Credit: 18,018 RAC: 0 |
David A also checked in a change to the wrapper. I'll save you all the effort of looking :) Author: davea Kathryn :o) The BOINC FAQ Service The Unofficial BOINC Wiki The Trac System More BOINC information than you can shake a stick of RAM at. |
Send message Joined: 14 Jul 05 Posts: 275 Credit: 49,291 RAC: 0 |
LHC doesn't even use a wrapper, that's why it's strange its priority is wrong. |
Send message Joined: 1 Sep 04 Posts: 275 Credit: 2,652,452 RAC: 0 |
LHC doesn't even use a wrapper, that's why it's strange its priority is wrong. It is a very old app. If I remember correctly the app we were testing on the alpha side was better behaved, however the alpha project ended before it had passed all the tests. BOINC WIKI BOINCing since 2002/12/8 |
Send message Joined: 14 Jul 05 Posts: 21 Credit: 3,486,046 RAC: 0 |
Why are you the only one having this problem with LHC and other projects? He's not the only one... I had the same problem but did not check the priority, because I thought it was a problem of the newest BOINC client. But after the LHC WU was completed, everything came back to the normal speed. |
©2024 CERN