Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, Thank you very much for spending so much effort on the threading affinity (re)design. It is very much appreciated. Christian ___ osg-users mailing list osg-users@lists.openscenegraph.org

Re: [osg-users] SingleThreaded leading to whole application just running on one core

I have now implemented support for manually setting the Affinity of the various threads that the viewer manages - so main thread, camera's, graphics threads and database pager threads. You'll now can set these via: osg::Camera::setProcessorAffinity(OpenThreads::Affinity);

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi All, I have now implemented the new OpenThreads::Affinity class in Windows, this is now checked in the the openthreads_affinity_mask branch. at the same time I spotted a missing feature - I'm not the author of OpenThreads and hadn't need to touch the Win32 implementation before so hadn't

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi all, I have refined the affinity support in OpenThreads further introducing an OpenThreads::Affinity class that stores a set of CPU core numbers that the affinity should be set for, this is then used as input when setting the the native threading API's CPU affinity mask. The Affinity class

Re: [osg-users] SingleThreaded leading to whole application just running on one core

HI Temia, On 26 September 2016 at 19:41, Temia Eszteri wrote: > Just let it drop! Drop what? The project leadership? Doing support for free? Investigating issues and getting to the bottom of them? If you've actually followed this thread and read what's been written

Re: [osg-users] SingleThreaded leading to whole application just running on one core

When reviewing doing a code review of the affinity code in OpenThreads today I noticed that OpenThreads doesn't fully expose all the functionality available for setting or resetting the thread affinity, as OpenThrreads just allowed you to specify a single cpu number for a thread to have affinity

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hey Robert, Just let it drop! Love, Temia On Mon, 26 Sep 2016 16:38:19 +0100 Robert Osfield wrote: > HI Christian, > > When it comes to perspectives of what is right or wrong for the OSG it > absolutely has everything to do with my experience. I more than > anyone

Re: [osg-users] SingleThreaded leading to whole application just running on one core

HI Christian, On 26 September 2016 at 15:49, Christoph Weiss wrote: > Robert, I'm not quite sure what prompts you to bring in personal attributes > here. Nor do I see any hyperbole to begin with. I stated that I strongly > disagree. You can in turn disagree. I never was my

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, On 09/26/2016 04:35 PM, Robert Osfield wrote: HI Christoph, On 26 September 2016 at 14:20, Christoph Weiss wrote: I strongly disagree with the last sentence. It is the most general use case possible: using standard C++ features. Please quite the hyperbole.

Re: [osg-users] SingleThreaded leading to whole application just running on one core

HI Christoph, On 26 September 2016 at 14:20, Christoph Weiss wrote: > I strongly disagree with the last sentence. It is the most general use case > possible: using standard C++ features. Please quite the hyperbole. It does you no favours. I am been writing C++ programs

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, If you are using OpenThreads for your threads then you have no problem at all anyway, you can create them before or after viewer.realizer() without any problem. It's only if you create your threads afterwards using another threading library that doesn't set the affinity mask in any

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Sebastian, On 26 September 2016 at 12:15, Sebastian Messerschmidt wrote: > Would a small function to enable/disable the affinity in SingleThreaded mode > be a big breaking change? Defaulting to using the affinity mask, making it > up to the advanced user to

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, I Hi All, I have taken Christoph's test problem and reproduced the affinity issue on my Kubuntu 16.04, so this is useful first step. I've also reviewed the OpenThreads code, so have a better idea of the code in question. Please note that I'm not the author of OpenThreads, the

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi All, I have taken Christoph's test problem and reproduced the affinity issue on my Kubuntu 16.04, so this is useful first step. I've also reviewed the OpenThreads code, so have a better idea of the code in question. Please note that I'm not the author of OpenThreads, the project just fell on

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Christoph, On 26 September 2016 at 11:01, Christoph Weiss wrote: > This sounds a bit as if this was a rare thing to do, or at least a design > choice that can or should be avoided. I think on the contrary, explicit > thread handling is something that is slowly going to die

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Dear Robert, On 09/26/2016 09:39 AM, Robert Osfield wrote: The only "difficulty" is when using a certain usage model when threading, it's not a general issue. The issue looks to be isolated to the case where users set up threads after the viewer has been realized. This sounds a bit as if

Re: [osg-users] SingleThreaded leading to whole application just running on one core

HI Fabien, On 25 September 2016 at 22:52, Fabian Wiesel wrote: > Yes, both cause the threads being distributed across the cores. That is > probably also why initialising TBB early in main helps, as it creates a pool > of worker threads. For my app, you can consider it

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, > Have you tried setting the affinity of the threads that are created? > Have you tried creating the threads before the call to viewer.realize()? Yes, both cause the threads being distributed across the cores. That is probably also why initialising TBB early in main helps, as it

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Thanks for the example Fabian, I'm away from my desktop system this weekend, will have a look in the week. Have you tried setting the affinity of the threads that are created? Have you tried creating the threads before the call to viewer.realize()? The way things are behaving looks to be down

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi, I can confirm the behaviour with the following test case: https://github.com/fwiesel/vertexarrayfunctest/blob/threads/main.cpp#L92-L103 All threads run on CPU 0. That clears up the mystery, which baffled me and two of my colleagues: After upgrading to a new Ubuntu version, suddenly our

Re: [osg-users] SingleThreaded leading to whole application just running on one core

I wrote a simple sample program that produces the following output: % g++ -std=c++14 -losgViewer -pthread a.cpp && time ./a.out Thread 5 done Thread 9 done Thread 4 done Thread 0 done Thread 6 done Thread 15 done Thread 12 done Thread 13 done Thread 11 done Thread 7 done Thread 8 done Thread 1

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi, > OSG is setting the affinity for some of its own threads, which is totally > legitimate. Currently, I was not able to confirm it on my Mac. But I think, I observed such a behaviour in my application on Linux. But take it with a grain of salt, as it can be the result of some other side

Re: [osg-users] SingleThreaded leading to whole application just running on one core

OK, Apologies if I caused offense. Goodbye. -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=68731#68731 ___ osg-users mailing list osg-users@lists.openscenegraph.org

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Pete, > I have no particular desire to repeat the last discussion, but i'll say it > again. But then you'lll throw is some ill-informed and emotive language anyway. >From my experience of maintaining an open source project for 17 years is that emotive language is used when people have a

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi, Wow, before this escalates: OSG is setting the affinity for some of its own threads, which is totally legitimate.And I totally agree, that it would be nice to have an interface to control the core/wether affinity is used in single-threaded mode except from having to subclass the viewer.

Re: [osg-users] SingleThreaded leading to whole application just running on one core

On 09/24/2016 02:18 AM, Pete Black wrote: I have no particular desire to repeat the last discussion, but i'll say it again. Hardcoding CPU affinity is: a) unexpected In particular it is not done by some osg::setThreadingModel() but rather deep down in the call stack by a function that is

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Chris, On 23 September 2016 at 09:19, Christoph Weiss wrote: > This actually has a very bad side effect that I only noticed now. Since it > explicitly sets the affinity to core zero, any other application that does > so will share its CPU entirely with it. In particular

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, When running SingleThread the OSG just sets the affinity of the current thread. That's it, that's all it's doing. This actually has a very bad side effect that I only noticed now. Since it explicitly sets the affinity to core zero, any other application that does so will share

Re: [osg-users] SingleThreaded leading to whole application just running on one core

On 23 September 2016 at 08:42, Christoph Weiss wrote: > Thank you so much for pointing this out, Pete. So in > ViewerBase::setUpThreading() osg decides the whole application should be > confined to a single core. When running SingleThread the OSG just sets the affinity of the

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Hi Robert, wouldn't it be a better approach to give the user the option to change such a setting for their application? But thanks for pointing out the subclassing option, that's what I'll go for! Still it took me half a day to track down what was going on. (I didn't suspect OSG in the

Re: [osg-users] SingleThreaded leading to whole application just running on one core

Thank you so much for pointing this out, Pete. So in ViewerBase::setUpThreading() osg decides the whole application should be confined to a single core. Judging by your comment, this has already been discussed and not deemed a fault that should be fixed? Also, I suppose there is no way to

Re: [osg-users] SingleThreaded leading to whole application just running on one core

On 23 September 2016 at 05:25, Pete Black wrote: > This is, bizarrely, by design. > > In single-threaded mode, OpenSceneGraph silently sets CPU affinity to a > single core by default. Personally I think this is incredibly obtrusive on > the programmer, and the reasons

Re: [osg-users] SingleThreaded leading to whole application just running on one core

This is, bizarrely, by design. In single-threaded mode, OpenSceneGraph silently sets CPU affinity to a single core by default. Personally I think this is incredibly obtrusive on the programmer, and the reasons for this being default behaviour are terrible, but it is what it is. This is what I