shared memory problem on ARM v5TE using threads

[Russell King - ARM Linux]

On Tue, Dec 15, 2009 at 04:31:35PM +0100, christian pellegrin wrote:
> The patch here does what was described by Russell and seems to solve
> the read/write and the MAP_PRIVATE in test cases like the one I
> posted. As noted it may not be enough.

This might be enough (but needs thorough testing).  However, adding
the requirement for L2 cache flushing in flush_dcache_page() because
you have an L2 cache is unfair on those L2's which don't suffer from
this problem.

I think we need to have a little more information about the behaviour
of the L2 cache so that we can decide how much flushing is required,
and where.