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Bug#216933: more thoughts on the X_ChangeProperty problem



It's almost encouraging to hear that Christopher Hart has the same
problem I do. I had begun to truely distrust my hardware. I wonder what
hardware Christopher is using?

I still see the problem, on a perhaps slightly less frequent basis, but
still every other day or so. I have not managed to correlate it with
changes in temperature, or much else except I agree with Christopher
that mozilla-firebird seems to often trigger it, as does xchat.

I had a horrible idea this morning, that almost makes sense. My lifefook
has a transmeta cpu in it, and this cpu has its code morhping
technology, which recompiles the i386 code on the fly to it internal
instruction set, and optimises it. As I understand it, the optimised
form is then used for that block of code as long as it remains cached,
even if a different program is started.

So: what if there is a bug in the optimizer, which generates incorrect
optimised code for either the X server, or X library, but only
sometimes. Some kind of math error might be involved. Once the badly
optimised code pops up, it would stay in the cache and this would
explain why even restarting X does not solve the problem. Presumably
certian workloads would knock it out of the cache, which would explain
the problem sometimes fixing itself. And rebooting the system (or
software suspending it) would likewise clear the cache.

This is a dreadful idea, but if true then I predict that Christopher has
a transmeta CPU as well. Frankly, I hope he doesn't..

Of course, I used X on this laptop for nearly 2 years before the problem
surfaced, so it could easily be that the optimisation bug is triggered
by something unlikely that has only recently been put in X, or in the
version of gcc used to build it.

Also, FWIW, I am now using the xserver-xfree86 4.3.0-0pre1v5 from
experimental, but am still using the old libraries, and have still
experienced the problem.

-- 
see shy jo

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