[Users] compiler warning for McLachlan

[Ian Hinder]

On 27 Sep 2011, at 18:00, Erik Schnetter wrote:

> On Tue, Sep 27, 2011 at 11:50 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>> If they have VECTORISE = yes (the proposed default for the new release of the ET) and VECTORISE_INLINE = yes (the current default, which I propose should be changed to "no"), and they try to compile McLachlan, the behaviour will be as Frank saw, which is that you get a warning and the compiler runs out of memory.  If the Ranger head node is configured such that a user can bring down the system by running a program which takes up a lot of memory, then the head node will go down.  This is common for default linux installs (I don' t know why), but Ranger has a ulimit setting of 8 GB for virtual memory, so I think the process will be terminated when it uses more than 8 GB, which is a sensible precaution for a production system.
> 
> This depends very much on the compiler, the compiler version, and the
> options chosen. A good compiler won't use too much memory when
> optimizing; this is really a compiler bug (that we should report).
> 
> I regularly encounter cases where a compiler takes a long time, runs
> out of memory, or outputs an error message that it stopped optimizing.
> Or the compiler crashes, sometimes in debug mode and without
> optimizing. What I usually do is either modify the source or the
> Simfactory options. We simply need to do the same here. (There's no
> need to be afraid that Ranger will explode, it didn't explode in the
> past either.)
> 
> Frank, which machine was this? Which compiler version? What options
> did you use? Could you open a trac issue about this?

This was numrel07, he was using numrel.cfg from simfactory.  I reproduced his problem in Datura by setting VECTORISE_INLINE = yes.  I think we should just change the default in Vectors to VECTORISE_INLINE = no.  Do you think this is a bad idea?  If so, why?

-- 
Ian Hinder
ian.hinder at aei.mpg.de