Re: mprotect and SMP

[Gavin Hemphill <hemphill@drea.dnd.ca>]

I have just tried the program with the latest bk 2_2 tree (pulled four
hours ago) on both the quad 750 and quad 7400.  It still fails.  I also
built the kernel with the L2 caches disabled and that fails as well.
The same kernel built uni-processor passes on both boards.  I had
thought it might be a cacheing issue, but if it is, it's got to be level
1 cache.  I'm still at a loss as to where to start looking for the
problem.  All I can say is help!

I'll package up gemini specific patches to let the 2_2 tree boot
sometime this weekend and forward them.
	Gavin

Benjamin Herrenschmidt wrote:
>
> >(2.2.18-pre11) which uses the mprotect call to lock pages between the
> >threads.  If I run the test program on this machine in SMP mode, it
> >fails (threads tromp on their shared memory locations).  If I run in
> >uni-processor mode however it works fine.  It also works fine on a dual
> >processor pentium using a similar version of the kernel.  The question
> >is... Has anyone seen this sort of behavior and are there any suggested
> >places to start looking to fix it?  I took a look at the gemini specific
> >files to see if there were any obvious missing eieio or sync
> >instructions and so far haven't seen any, but I don't have the
> >experience to know where else I should be looking.
>
> Can you get the latest bitkeeper _2_2 tree or paulus latest rsync
> tree and see if it still happens ?
>
> Ben.


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