Re: [eigen] Status of non-OpenMP-based multithreading

[Mark Borgerding <mark@xxxxxxxxxxxxxx>]

"me too too" on keeping threading as an option for another reason -- because threading can often be done more effectively at higher levels (e.g. "embarassingly parallel" work units).

-- Mark

On 03/07/2016 11:38 AM, Jason Newton wrote:

"me too" on being able to disable all things threading for the same reasons as Ola here.  I've often turned to Eigen in situations where I just want plain old number processing code, with no magic.  This would also be problematic if Eigen wants to stay GPU compatible.

-Jason

On Mon, Mar 7, 2016 at 11:32 AM, Ola Røer Thorsen <ola@xxxxxxxxxxxxxx> wrote:

Hi list,

2016-03-07 17:15 GMT+01:00 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:

I actually like having threading opt-in. This also fits better with having multiple coexisting paths, letting the user choose between them; indeed, I think it's important here to acknowledge the absence of a single universal solution: neither OpenMP nor C++11 are universal as far as Eigen is concerned, and both hide enough 'magic' in their implementation that we can easily imagine having users running into trouble on a particular implementation (concretely, at least some Android toolchains have a very poorly performing implementation of C++11 threads).

I agree with opt-in for threading. I'm using Eigen on "bare metal" single-core microcontrollers that has no OS at all, and it would be a hassle to have to somehow emulate C++11 threads or similar. It is really easy getting Eigen going on these devices the way it is now.

Best regards,

Ola Røer Thorsen