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From: Jeff King <peff@peff.net>
To: Thomas Rast <trast@student.ethz.ch>
Cc: "Stefan Zager" <szager@google.com>,
	git@vger.kernel.org, "Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
Subject: Re: regression in multi-threaded git-pack-index
Date: Tue, 19 Mar 2013 05:30:34 -0400	[thread overview]
Message-ID: <20130319093034.GA29997@sigill.intra.peff.net> (raw)
In-Reply-To: <87fvzrajmr.fsf@pctrast.inf.ethz.ch>

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

> > 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.

-Peff

  reply	other threads:[~2013-03-19  9:31 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-15 22:42 regression in multi-threaded git-pack-index Stefan Zager
2013-03-16 11:41 ` Jeff King
2013-03-16 12:38   ` Duy Nguyen
2013-03-19  8:17   ` Thomas Rast
2013-03-19  9:30     ` Jeff King [this message]
2013-03-19  9:59       ` Jeff King
2013-03-19 10:08         ` Jeff King
2013-03-19 10:24           ` Jeff King
2013-03-19 10:29             ` Thomas Rast
2013-03-19 10:33               ` Jeff King
2013-03-19 10:45                 ` Thomas Rast
2013-03-19 10:47                   ` Jeff King
2013-03-19 10:58             ` [PATCH] index-pack: always zero-initialize object_entry list Jeff King
2013-03-19 15:33               ` Thomas Rast
2013-03-19 15:43                 ` Jeff King
2013-03-19 15:52                   ` Jeff King
2013-03-19 16:17                     ` [PATCH v2] " Jeff King
2013-03-19 16:27                       ` Thomas Rast
2013-03-19 17:13                         ` Junio C Hamano
2013-03-20 19:12                       ` Eric Sunshine
2013-03-20 19:13                         ` Jeff King
2013-03-20 19:14                           ` Eric Sunshine
2013-03-19 12:35     ` regression in multi-threaded git-pack-index Duy Nguyen
2013-03-19 13:01       ` [PATCH] index-pack: protect deepest_delta in multithread code Nguyễn Thái Ngọc Duy
2013-03-19 13:25         ` Jeff King
2013-03-19 13:50         ` Thomas Rast
2013-03-19 14:07           ` Duy Nguyen
2013-03-19 14:16             ` [PATCH v2] index-pack: guard nr_resolved_deltas reads by lock Thomas Rast
2013-03-19 15:53               ` Junio C Hamano
2013-03-19 15:41 ` regression in multi-threaded git-pack-index Thomas Rast
2013-03-19 15:45   ` Thomas Rast
2013-03-19 16:11     ` Thomas Rast
2013-03-19 17:58       ` Junio C Hamano
2013-03-19 22:08         ` [PATCH] sha1_file: remove recursion in packed_object_info Thomas Rast
2013-03-20 16:47           ` Junio C Hamano
2013-03-25  9:27             ` thomas
2013-03-25 18:07               ` [PATCH v2 0/3] Recursion-free unpack_entry and packed_object_info Thomas Rast
2013-03-25 18:07                 ` [PATCH v2 1/3] sha1_file: remove recursion in packed_object_info Thomas Rast
2013-03-25 18:07                 ` [PATCH v2 2/3] Refactor parts of in_delta_base_cache/cache_or_unpack_entry Thomas Rast
2013-03-25 23:15                   ` Junio C Hamano
2013-03-26 11:09                     ` thomas
2013-03-25 18:07                 ` [PATCH v2 3/3] sha1_file: remove recursion in unpack_entry Thomas Rast
2013-03-25 23:19                   ` Junio C Hamano
2013-03-26  3:37                 ` [PATCH v2 0/3] Recursion-free unpack_entry and packed_object_info Nicolas Pitre
2013-03-25 18:17               ` [PATCH] sha1_file: remove recursion in packed_object_info Junio C Hamano
2013-03-27 20:03               ` [PATCH v3 0/3] Recursion-free unpack_entry and packed_object_info Thomas Rast
2013-03-27 20:03                 ` [PATCH v3 1/3] sha1_file: remove recursion in packed_object_info Thomas Rast
2013-03-27 20:03                 ` [PATCH v3 2/3] Refactor parts of in_delta_base_cache/cache_or_unpack_entry Thomas Rast
2013-03-27 20:03                 ` [PATCH v3 3/3] sha1_file: remove recursion in unpack_entry Thomas Rast
2013-03-27 20:29                   ` Junio C Hamano
2013-03-20  1:17       ` regression in multi-threaded git-pack-index Duy Nguyen

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