[SLOF] [PATCH 3/4] fbuffer: Implement MRMOVE as an accelerated primitive

[Nikunj A Dadhania]

Thomas Huth <thuth at redhat.com> writes:

> On 10/09/15 14:00, Nikunj A Dadhania wrote:
>> Thomas Huth <thuth at redhat.com> writes:
>> 
>>> On 09/09/15 13:37, Nikunj A Dadhania wrote:
>>>> Thomas Huth <thuth at redhat.com> writes:
>>>>
>>>>> On 09/09/15 13:05, Nikunj A Dadhania wrote:
>>>>>> Thomas Huth <thuth at redhat.com> writes:
>>>>>>
>>>>>>> On 09/09/15 08:45, Nikunj A Dadhania wrote:
> ...
>>>>>>>> TCG seem to be broken with this new series, git bisect pointed to:
>>>>>>>>
>>>>>>>> 59a135e fbuffer: Implement MRMOVE as an accelerated primitive
>>>>>>>>
>>>>>>>> I havent looked into detail of why its failing though.
> ...
>>>
>>> I've did some more tests, and it occurs for me, too, when I use the ATC
>>> compiler instead of my normal cross-compiler from my distro!
>> 
>> I am using:
>> 
>> $ powerpc64-linux-gnu-gcc --version
>> powerpc64-linux-gnu-gcc (GCC) 5.1.1 20150422 (Red Hat Cross 5.1.1-1)
>
> Ok, I've also install ATC 7.0, and with that it seems to be working
> fine, too.
>
> So we've got:
> - RHEL 7.1 cross-compiler (gcc 4.8.1) : working
> - AT 7.0 cross-compiler (gcc 4.8.5) : working
> - AT 8.0 cross-compiler (gcc 4.9.3) : not working
> - Your (Fedora?) cross-compiler (gcc 5.1.1) : not working

Fedora 22

>
> I guess newer GCCs are using some kind of additional optimization that
> clashes with a hidden SLOF bug - triggered by my recent patches.
> I've stared at the code of my recent patches for quite a while now, but
> I can't see anything wrong in there. Even worse, when you add some
> printf statements in _FASTRMOVE for example, you can see that the code
> is even not called before the "failed to include fbuffer.fs" error occurs!
>
> So this is really a confusing bug. Of course feel free to revert my
> patches if you like ... but unless we're sure that the bug is in my
> patches, this might also just temporarily solve this issue...

Dont think it should be in your patches, i had a look at them.

Regards
Nikunj