[Beignet] thread safety and OpenMP

[Zhigang Gong]

Gerald,

Unfortunately, beignet does have some thread-safe bugs, and I recently found and fixed some of them
Not sure whether these fixes are enough for you, but you can still have a try and let us know the result.

If you can still reproduce the problem, it may be helpful to file a bug at bugzilla and describe how to reproduce
the issue. The bugzilla link is as below:
https://bugs.freedesktop.org/enter_bug.cgi?product=Beignet

Thanks,
Zhigang Gong.

> -----Original Message-----
> From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of
> Gerald Baier
> Sent: Thursday, July 2, 2015 4:02 AM
> To: He, Junyan; Song, Ruiling; Gerald Baier; beignet at lists.freedesktop.org
> Subject: Re: [Beignet] thread safety and OpenMP
> 
> On 07/01/2015 07:28 AM, He, Junyan wrote:
> > So far as we know, beignet is thread safe.
> > Every thead has its own command buffer and do not have relationship
> > with each others.
> > Do you use subbuffer to divide the image?
> No, as far as I can tell I don't use anything special or advanced.
> > If you can provide some source code or test case, it may help a lot.
> I'll try to hack together a minimal example over the weekend.
> 
> Thanks already for your feedback. Cheers.
> >
> >
> >
> > -----Original Message-----
> > From: Song, Ruiling
> > Sent: Wednesday, July 01, 2015 10:40 AM
> > To: Gerald Baier; beignet at lists.freedesktop.org
> > Cc: He, Junyan
> > Subject: RE: [Beignet] thread safety and OpenMP
> >
> >
> >
> >> -----Original Message-----
> >> From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On
> >> Behalf Of Gerald Baier
> >> Sent: Sunday, June 28, 2015 9:56 PM
> >> To: beignet at lists.freedesktop.org
> >> Subject: [Beignet] thread safety and OpenMP
> >>
> >> I'm using Beignet for image processing, where basically the image is
> >> subdivided into tiles which are then processed by several threads
> >> using OpenMP tasks. I noticed that some of the tiles are occasionally
> >> messed up. If
> >
> > Using OpenMP or OpenCL?
> > Per OpenCL spec, opencl driver should be thread-safe, and Junyan
> implemented the multi-thread support in beignet. That is to say Beignet is
> thread-safe.
> > I am not sure whether Junyan has more comments on how to debug the issue.
> By the way, if you can provide a test case to reproduce the issue, it would be
> much helpful.
> >
> > Thanks!
> > Ruiling
> >> I use only one thread everything works fine, also the same program
> >> runs as expected on nvidia GPUs with multiple threads. Hence the
> >> question whether Beignet is thread safe and how I could debug my
> program?
> >>
> >> Here's my configuration:
> >> device name: Intel(R) HD Graphics IvyBridge M GT2 device version:
> >> OpenCL
> >> 1.2 beignet 1.0.3 (git-9e0ca6f)
> >>
> >> Best regards,
> >> Gerald
> >>
> >> _______________________________________________
> >> Beignet mailing list
> >> Beignet at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/beignet
> 
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