mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Software

Reply
 
Thread Tools
Old 2008-11-04, 09:11   #1
worknplay
 
worknplay's Avatar
 
Aug 2002
Victoria, BC, Canada

10012 Posts
Question Multi-Core / Multi-CPU Assignments (missing)

I've made a successful conversion over to v25 and have lost no work doing so - always make backups before you update anything!

Now, in cheking my v25 assignment details in my account I've noticed that where I have multi-core CPUs (2) or multi-CPU boxes (1), the Assignment Details report is only showing assignments for n-1 of my multi-core/cpu computers (where 'n' = number of core's/cpu's).

i.e. I have a Core2-Quad and I'm only seeing assignments for core's 1, 2 & 3 (no core 0 [4?]) .. my Core2-Duo is the same, I only see work assignment for core 1 (nada for core 0 [2?]). Ditto for my dual-CPU single-core Xeon box - only Xeon CPU 1 is showing assigned work (nothing for CPU 0 [2?]).

I have work assigned to ALL my core's and CPU's and v25 has been running nicely for at least 4-5 days (so work for all core's and CPUs has been reported to the Primenet Server)

Anyone else experiencing this in their assignment reports?

Last fiddled with by worknplay on 2008-11-04 at 09:14
worknplay is offline   Reply With Quote
Old 2008-11-04, 09:23   #2
opyrt
 
opyrt's Avatar
 
Apr 2008
Oslo, Norway

7×31 Posts
Default

Are you sure it's not saying that it's starting helper threads on 3 CPUs and starting 4 threads? :)

In other words, it's starting 1 main worker thread and 3 helper threads for that worker. That is what is happening on my computer and I can see that it utilizing approx. 100% CPU.

[Nov 4 08:02] Using all-complex FFT length 1536K, 4 threads
^-- Starting 4 threads.

[Nov 4 08:02] Setting affinity to run helper thread 1 on any logical CPU.
[Nov 4 08:02] Setting affinity to run helper thread 2 on any logical CPU.
[Nov 4 08:02] Setting affinity to run helper thread 3 on any logical CPU.

^--- Starting 3 helper threads.
opyrt is offline   Reply With Quote
Old 2008-11-05, 00:19   #3
Richard Otter
 
Nov 2008

510 Posts
Default

I see the same behavior you described.
Richard Otter is offline   Reply With Quote
Old 2008-11-05, 17:26   #4
worknplay
 
worknplay's Avatar
 
Aug 2002
Victoria, BC, Canada

32 Posts
Default

After doing some investigation, I've come to the conclusion that exponents originally assigned by the v4 server will show up as assignments to v4_computers despite the exponents having been moved to the v25 client and that work being registered with the v5 server.

For TF exponents, this will usually clear itself within a few days depending on how much work has been queued. For LL exponents assigned by the v4 server, I expect this anomaly will clear once the exponent has completed testing and a new LL exponent is assigned by the v5 server.

Part of the problem also is that in converting my computers to the v25 client, I had done so without fully realizing what the v25 client was capable of (i.e. running separate threads from one client). Having two multi-core and one dual-CPU computers, I simply backed-up each v24 client folder and dropped the new v25 client files into each folder and started the clients up - on a Core2-Quad the result was each of the four v25 clients now running detected the presence of a quad-core CPU and thus requested work for four threads each .. you do the math.

Quickly recognizing what I had done, I stopped all four clients, "decommissioned" three of four (on the Quad-core) of my v24 folders (with the v25 client) and transferred the work they had requested from the v5 server to the now primary v25 client's worktodo.txt file (had to do this twice over for my dual-CPU server and Core2-Duo workstation having upgraded them to the v25 client before recognizing my mistake) ..

It will be a couple weeks before any of my assigned LL exponents are completed testing, so my conclusion won't be proven (or disproved) till then - unless of course someone else has a similar situation where their work is completed sooner.

Cheers,
worknplay is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
multi-core TF dbaugh Information & Answers 3 2011-09-06 01:32
GMP-Fermat and multi-core processors ixfd64 Factoring 1 2011-03-16 16:07
Automatic multi-core detect and use? remaker Software 11 2007-04-02 20:18
CGPU multi core x86, Intel Larrabee dsouza123 Hardware 2 2007-02-14 18:00
My prediction about multi-core chips jasong Hardware 6 2006-02-14 16:07

All times are UTC. The time now is 18:40.

Tue Aug 11 18:40:41 UTC 2020 up 25 days, 14:27, 2 users, load averages: 1.76, 1.74, 1.61

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.