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From: Taylor Blau <me@ttaylorr.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Taylor Blau <me@ttaylorr.com>,
	git@vger.kernel.org, peff@peff.net, dstolee@microsoft.com,
	szeder.dev@gmail.com
Subject: Re: [PATCH v2 12/14] commit-graph: add large-filters bitmap chunk
Date: Wed, 5 Aug 2020 18:25:31 -0400	[thread overview]
Message-ID: <20200805222531.GA30420@syl.lan> (raw)
In-Reply-To: <xmqqh7tgn37w.fsf@gitster.c.googlers.com>

On Wed, Aug 05, 2020 at 03:21:39PM -0700, Junio C Hamano wrote:
> Taylor Blau <me@ttaylorr.com> writes:
>
> > On Wed, Aug 05, 2020 at 02:01:29PM -0700, Junio C Hamano wrote:
> >> Taylor Blau <me@ttaylorr.com> writes:
> >>
> >> > @@ -71,6 +72,10 @@ struct commit_graph {
> >> >  	const unsigned char *chunk_base_graphs;
> >> >  	const unsigned char *chunk_bloom_indexes;
> >> >  	const unsigned char *chunk_bloom_data;
> >> > +	const unsigned char *chunk_bloom_large_filters;
> >> > +
> >> > +	size_t bloom_large_to_alloc;
> >> > +	struct bitmap bloom_large;
> >>
> >> Hmph, is the API rich enough to allow users to release the resource
> >> used by such an embedded bitmap?  I ask becuase...
> >>
> >> > @@ -2503,6 +2577,7 @@ void free_commit_graph(struct commit_graph *g)
> >> >  	}
> >> >  	free(g->filename);
> >> >  	free(g->bloom_filter_settings);
> >> > +	bitmap_free(g->bloom_large);
> >> >  	free(g);
> >> >  }
> >>
> >> ... this hunk cannot be possibly correct as-is, and cannot be made
> >> correct without changing g->bloom_large to a pointer into a heap
> >> allocated bitmap, because bitmap_free() wants to not just release
> >> the resource held by the bitmap but the bitmap itself.
> >
> > Yuck, that's definitely wrong. Serves me right for sneaking this in
> > after I had run `git rebase -x 'make -j40 DEVELOPER=1 test'
> > upstream/master` ;-).
> >
> > Below the scissors line should do the trick. It should apply cleanly at
> > this point in the series, but it'll produce a compilation failure on the
> > very last patch (fixing it is straightforward and looks like the
> > following diff):
> >
> > diff --git a/bloom.c b/bloom.c
> > index d0c0fd049d..8d07209c6b 100644
> > --- a/bloom.c
> > +++ b/bloom.c
> > @@ -52,7 +52,7 @@ static int load_bloom_filter_from_graph(struct commit_graph *g,
> >                 start_index = 0;
> >
> >         if ((start_index == end_index) &&
> > -           (g->bloom_large.word_alloc && !bitmap_get(&g->bloom_large, lex_pos))) {
> > +           (g->bloom_large && !bitmap_get(g->bloom_large, lex_pos))) {
> >                 /*
> >                  * If the filter is zero-length, either (1) the filter has no
> >                  * changes, (2) the filter has too many changes, or (3) it
> >
> > In either case, this will fix the bad free():
> >
> > --- >8 ---
> >
> > Subject: [PATCH] fixup! commit-graph: add large-filters bitmap chunk
> >
> > Signed-off-by: Taylor Blau <me@ttaylorr.com>
> > ---
> >  commit-graph.c | 18 ++++++++++--------
> >  commit-graph.h |  2 +-
> >  2 files changed, 11 insertions(+), 9 deletions(-)
> > ...
> > @@ -2360,6 +2361,7 @@ int write_commit_graph(struct object_directory *odb,
> >  	free(ctx->graph_name);
> >  	free(ctx->commits.list);
> >  	free(ctx->oids.list);
> > +	free(ctx->bloom_large);
>
> Is this correct, or shouldn't it be bitmap_free() instead?

Ack, that should be 'bitmap_free()'. Double checking, 'bitmap_free' does
handle a 'NULL' argument like 'free', so dealing with an old
commit-graph lacking this chunk will work fine.

Thanks for catching my mistake. I'm off tomorrow, Friday, and Monday,
so my responses from now on may be intermittent, but I should have some
time.

Thanks,
Taylor

  reply	other threads:[~2020-08-05 22:25 UTC|newest]

Thread overview: 117+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-03 18:57 [PATCH 00/10] more miscellaneous Bloom filter improvements Taylor Blau
2020-08-03 18:57 ` [PATCH 01/10] commit-graph: introduce 'get_bloom_filter_settings()' Taylor Blau
2020-08-04  7:24   ` Jeff King
2020-08-04 20:08     ` Taylor Blau
2020-08-03 18:57 ` [PATCH 02/10] commit-graph: pass a 'struct repository *' in more places Taylor Blau
2020-08-03 18:57 ` [PATCH 03/10] t4216: use an '&&'-chain Taylor Blau
2020-08-03 18:57 ` [PATCH 04/10] t/helper/test-read-graph.c: prepare repo settings Taylor Blau
2020-08-03 18:57 ` [PATCH 05/10] commit-graph: respect 'commitgraph.readChangedPaths' Taylor Blau
2020-08-03 18:57 ` [PATCH 06/10] commit-graph.c: sort index into commits list Taylor Blau
2020-08-04 12:31   ` Derrick Stolee
2020-08-04 20:10     ` Taylor Blau
2020-08-03 18:57 ` [PATCH 07/10] commit-graph: add large-filters bitmap chunk Taylor Blau
2020-08-03 18:59   ` Taylor Blau
2020-08-04 12:57   ` Derrick Stolee
2020-08-03 18:57 ` [PATCH 08/10] bloom: split 'get_bloom_filter()' in two Taylor Blau
2020-08-04 13:00   ` Derrick Stolee
2020-08-04 20:12     ` Taylor Blau
2020-08-03 18:57 ` [PATCH 09/10] commit-graph: rename 'split_commit_graph_opts' Taylor Blau
2020-08-03 18:57 ` [PATCH 10/10] builtin/commit-graph.c: introduce '--max-new-filters=<n>' Taylor Blau
2020-08-04 13:03   ` Derrick Stolee
2020-08-04 20:14     ` Taylor Blau
2020-08-05 17:01 ` [PATCH v2 00/14] more miscellaneous Bloom filter improvements Taylor Blau
2020-08-05 17:01   ` [PATCH v2 01/14] commit-graph: introduce 'get_bloom_filter_settings()' Taylor Blau
2020-08-05 17:02   ` [PATCH v2 02/14] t4216: use an '&&'-chain Taylor Blau
2020-08-05 17:02   ` [PATCH v2 03/14] commit-graph: pass a 'struct repository *' in more places Taylor Blau
2020-08-05 17:02   ` [PATCH v2 04/14] t/helper/test-read-graph.c: prepare repo settings Taylor Blau
2020-08-05 17:02   ` [PATCH v2 05/14] commit-graph: respect 'commitGraph.readChangedPaths' Taylor Blau
2020-08-05 17:02   ` [PATCH v2 06/14] commit-graph.c: store maximum changed paths Taylor Blau
2020-08-05 17:02   ` [PATCH v2 07/14] bloom: split 'get_bloom_filter()' in two Taylor Blau
2020-08-05 17:02   ` [PATCH v2 08/14] bloom: use provided 'struct bloom_filter_settings' Taylor Blau
2020-08-05 17:02   ` [PATCH v2 09/14] bloom/diff: properly short-circuit on max_changes Taylor Blau
2020-08-05 17:02   ` [PATCH v2 10/14] commit-graph.c: sort index into commits list Taylor Blau
2020-08-05 17:02   ` [PATCH v2 11/14] csum-file.h: introduce 'hashwrite_be64()' Taylor Blau
2020-08-05 17:02   ` [PATCH v2 12/14] commit-graph: add large-filters bitmap chunk Taylor Blau
2020-08-05 21:01     ` Junio C Hamano
2020-08-05 21:17       ` Taylor Blau
2020-08-05 22:21         ` Junio C Hamano
2020-08-05 22:25           ` Taylor Blau [this message]
2020-08-11 13:48             ` Taylor Blau
2020-08-11 18:59               ` Junio C Hamano
2020-08-05 17:03   ` [PATCH v2 13/14] commit-graph: rename 'split_commit_graph_opts' Taylor Blau
2020-08-05 17:03   ` [PATCH v2 14/14] builtin/commit-graph.c: introduce '--max-new-filters=<n>' Taylor Blau
2020-08-11 20:51 ` [PATCH v3 00/14] more miscellaneous Bloom filter improvements Taylor Blau
2020-08-11 20:51   ` [PATCH v3 01/14] commit-graph: introduce 'get_bloom_filter_settings()' Taylor Blau
2020-08-11 21:18     ` SZEDER Gábor
2020-08-11 21:21       ` Taylor Blau
2020-08-11 21:27         ` SZEDER Gábor
2020-08-11 21:34           ` Taylor Blau
2020-08-11 23:55             ` SZEDER Gábor
2020-08-12 11:48               ` Derrick Stolee
2020-08-14 20:17                 ` Taylor Blau
2020-08-11 20:51   ` [PATCH v3 02/14] t4216: use an '&&'-chain Taylor Blau
2020-08-11 20:51   ` [PATCH v3 03/14] commit-graph: pass a 'struct repository *' in more places Taylor Blau
2020-08-11 20:51   ` [PATCH v3 04/14] t/helper/test-read-graph.c: prepare repo settings Taylor Blau
2020-08-11 20:51   ` [PATCH v3 05/14] commit-graph: respect 'commitGraph.readChangedPaths' Taylor Blau
2020-08-11 20:51   ` [PATCH v3 06/14] commit-graph.c: store maximum changed paths Taylor Blau
2020-08-11 20:51   ` [PATCH v3 07/14] bloom: split 'get_bloom_filter()' in two Taylor Blau
2020-08-11 20:51   ` [PATCH v3 11/14] csum-file.h: introduce 'hashwrite_be64()' Taylor Blau
2020-08-11 20:51   ` [PATCH v3 08/14] bloom: use provided 'struct bloom_filter_settings' Taylor Blau
2020-08-11 20:51   ` [PATCH v3 09/14] bloom/diff: properly short-circuit on max_changes Taylor Blau
2020-08-11 20:52   ` [PATCH v3 10/14] commit-graph.c: sort index into commits list Taylor Blau
2020-08-11 20:52   ` [PATCH v3 12/14] commit-graph: add large-filters bitmap chunk Taylor Blau
2020-08-11 21:11     ` Derrick Stolee
2020-08-11 21:18       ` Taylor Blau
2020-08-11 22:05         ` Taylor Blau
2020-08-19 13:35     ` SZEDER Gábor
2020-09-02 20:23       ` Taylor Blau
2020-09-01 14:35     ` SZEDER Gábor
2020-09-02 20:40       ` Taylor Blau
2020-08-11 20:52   ` [PATCH v3 13/14] commit-graph: rename 'split_commit_graph_opts' Taylor Blau
2020-08-19  9:56     ` SZEDER Gábor
2020-09-02 21:02       ` Taylor Blau
2020-08-11 20:52   ` [PATCH v3 14/14] builtin/commit-graph.c: introduce '--max-new-filters=<n>' Taylor Blau
2020-08-12 11:49     ` SZEDER Gábor
2020-08-14 20:20       ` Taylor Blau
2020-08-17 22:50         ` SZEDER Gábor
2020-09-02 21:03           ` Taylor Blau
2020-08-12 12:29     ` Derrick Stolee
2020-08-14 20:10       ` Taylor Blau
2020-08-18 22:23     ` SZEDER Gábor
2020-09-03 16:35       ` Taylor Blau
2020-08-19  8:20     ` SZEDER Gábor
2020-09-03 16:42       ` Taylor Blau
2020-09-04  8:50         ` SZEDER Gábor
2020-09-01 14:36     ` SZEDER Gábor
2020-09-03 18:49       ` Taylor Blau
2020-09-03 21:45   ` [PATCH v3 00/14] more miscellaneous Bloom filter improvements Junio C Hamano
2020-09-03 22:33     ` Taylor Blau
2020-09-03 22:45 ` [PATCH v4 " Taylor Blau
2020-09-03 22:46   ` [PATCH v4 01/14] commit-graph: introduce 'get_bloom_filter_settings()' Taylor Blau
2020-09-03 22:46   ` [PATCH v4 02/14] t4216: use an '&&'-chain Taylor Blau
2020-09-03 22:46   ` [PATCH v4 03/14] commit-graph: pass a 'struct repository *' in more places Taylor Blau
2020-09-03 22:46   ` [PATCH v4 04/14] t/helper/test-read-graph.c: prepare repo settings Taylor Blau
2020-09-03 22:46   ` [PATCH v4 05/14] commit-graph: respect 'commitGraph.readChangedPaths' Taylor Blau
2020-09-03 22:46   ` [PATCH v4 06/14] commit-graph.c: store maximum changed paths Taylor Blau
2020-09-03 22:46   ` [PATCH v4 07/14] bloom: split 'get_bloom_filter()' in two Taylor Blau
2020-09-05 17:22     ` Jakub Narębski
2020-09-05 17:38       ` Taylor Blau
2020-09-05 17:50         ` Jakub Narębski
2020-09-05 18:01           ` Taylor Blau
2020-09-05 18:18             ` Jakub Narębski
2020-09-05 18:38               ` Taylor Blau
2020-09-05 18:55                 ` Taylor Blau
2020-09-05 19:04                   ` SZEDER Gábor
2020-09-05 19:49                     ` Taylor Blau
2020-09-06 21:52                       ` Junio C Hamano
2020-09-03 22:46   ` [PATCH v4 08/14] bloom: use provided 'struct bloom_filter_settings' Taylor Blau
2020-09-03 22:46   ` [PATCH v4 09/14] bloom/diff: properly short-circuit on max_changes Taylor Blau
2020-09-03 22:46   ` [PATCH v4 10/14] commit-graph.c: sort index into commits list Taylor Blau
2020-09-03 22:46   ` [PATCH v4 11/14] csum-file.h: introduce 'hashwrite_be64()' Taylor Blau
2020-09-04 20:18     ` René Scharfe
2020-09-04 20:22       ` Taylor Blau
2020-09-03 22:46   ` [PATCH v4 12/14] commit-graph: add large-filters bitmap chunk Taylor Blau
2020-09-03 22:46   ` [PATCH v4 13/14] commit-graph: rename 'split_commit_graph_opts' Taylor Blau
2020-09-04 15:20     ` Taylor Blau
2020-09-03 22:47   ` [PATCH v4 14/14] builtin/commit-graph.c: introduce '--max-new-filters=<n>' Taylor Blau
2020-09-04 14:39   ` [PATCH v4 00/14] more miscellaneous Bloom filter improvements Derrick Stolee

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