Re: regression in multi-threaded git-pack-index

On Tue, Mar 19, 2013 at 05:30:34AM -0400, Jeff King wrote:

On Tue, Mar 19, 2013 at 09:17:32AM +0100, Thomas Rast wrote:

quoted

quoted

but the line in question is:

  if (deepest_delta < delta_obj->delta_depth)

And in the debugger, both of those variables appear to have sane values
(nor should either impacted by the patch you bisected to). On top of
that, running with pack.threads=1 produces the same error. So I think it
may be a false positive from valgrind, and unrelated to your issue.

I find that somewhat unlikely, for two reasons: memcheck is actually
quite good at finding uninitialized memory use, it just isn't that good
at distinguishing if it makes a difference.  Most false positives are of
the "loading an entire word and discarding most of it" kind.

Yes, that has been my experience with valgrind false positives, too. But
if this is a real problem, it may be different from the OP's issue. It
seems to trigger for me in v1.7.10, before Duy's threading patches. It
does not seem to be in v1.7.5. I'm bisecting now.

Hmph. It bisects to Junio's d1a0ed1 (index-pack: show histogram when
emulating "verify-pack -v", 2011-06-03), which introduces those lines.
The deepest_delta variable is static, so by definition it is always
initialized to something. So I guess some objects may not have
delta_depth set. Still looking.

-Peff