From: Stephan Beyer <s-beyer@gmx.net>
To: git@vger.kernel.org
Cc: Stephan Beyer <s-beyer@gmx.net>,
Christian Couder <christian.couder@gmail.com>,
Junio C Hamano <gitster@pobox.com>
Subject: [PATCH v2 10/21] bisect: get rid of recursion in count_distance()
Date: Sun, 10 Apr 2016 15:19:03 +0200 [thread overview]
Message-ID: <1460294354-7031-11-git-send-email-s-beyer@gmx.net> (raw)
In-Reply-To: <1460294354-7031-1-git-send-email-s-beyer@gmx.net>
Large repositories with a huge amount of merge commits in the
bisection process could lead to stack overflows in git bisect.
In order to prevent this, this commit uses an *iterative* version
for counting the number of ancestors of a commit.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
---
bisect.c | 55 ++++++++++++++++++++++---------------------------------
1 file changed, 22 insertions(+), 33 deletions(-)
diff --git a/bisect.c b/bisect.c
index 1a13f35..16bbfa6 100644
--- a/bisect.c
+++ b/bisect.c
@@ -26,33 +26,23 @@ static const char *term_good;
/* Remember to update object flag allocation in object.h */
#define COUNTED (1u<<16)
-/*
- * This is a truly stupid algorithm, but it's only
- * used for bisection, and we just don't care enough.
- *
- * We care just barely enough to avoid recursing for
- * non-merge entries.
- */
static int count_distance(struct commit_list *entry)
{
int nr = 0;
+ struct commit_list *todo = NULL;
+ commit_list_append(entry->item, &todo);
- while (entry) {
- struct commit *commit = entry->item;
- struct commit_list *p;
+ while (todo) {
+ struct commit *commit = pop_commit(&todo);
- if (commit->object.flags & (UNINTERESTING | COUNTED))
- break;
- if (!(commit->object.flags & TREESAME))
- nr++;
- commit->object.flags |= COUNTED;
- p = commit->parents;
- entry = p;
- if (p) {
- p = p->next;
- while (p) {
- nr += count_distance(p);
- p = p->next;
+ if (!(commit->object.flags & (UNINTERESTING | COUNTED))) {
+ struct commit_list *p;
+ if (!(commit->object.flags & TREESAME))
+ nr++;
+ commit->object.flags |= COUNTED;
+
+ for (p = commit->parents; p; p = p->next) {
+ commit_list_insert(p->item, &todo);
}
}
}
@@ -287,7 +277,7 @@ static struct commit_list *do_find_bisection(struct commit_list *list,
* can reach. So we do not have to run the expensive
* count_distance() for single strand of pearls.
*
- * However, if you have more than one parents, you cannot
+ * However, if you have more than one parent, you cannot
* just add their distance and one for yourself, since
* they usually reach the same ancestor and you would
* end up counting them twice that way.
@@ -296,17 +286,16 @@ static struct commit_list *do_find_bisection(struct commit_list *list,
* way, and then fill the blanks using cheaper algorithm.
*/
for (p = list; p; p = p->next) {
- if (p->item->object.flags & UNINTERESTING)
- continue;
- if (weight(p) != -2)
- continue;
- weight_set(p, count_distance(p));
- clear_distance(list);
+ if (!(p->item->object.flags & UNINTERESTING)
+ && (weight(p) == -2)) {
+ weight_set(p, count_distance(p));
+ clear_distance(list);
- /* Does it happen to be at exactly half-way? */
- if (!find_all && halfway(p, nr))
- return p;
- counted++;
+ /* Does it happen to be at exactly half-way? */
+ if (!find_all && halfway(p, nr))
+ return p;
+ counted++;
+ }
}
show_list("bisection 2 count_distance", counted, nr, list);
--
2.8.1.137.g522756c
next prev parent reply other threads:[~2016-04-10 13:20 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-10 13:18 [PATCH v2 00/21] git bisect improvements Stephan Beyer
2016-04-10 13:18 ` [PATCH v2 01/21] bisect: write about `bisect next` in documentation Stephan Beyer
2016-04-10 13:18 ` [PATCH v2 02/21] bisect: allow 'bisect run' if no good commit is known Stephan Beyer
2016-04-10 13:18 ` [PATCH v2 03/21] t/test-lib-functions.sh: generalize test_cmp_rev Stephan Beyer
2016-04-11 0:07 ` Eric Sunshine
2016-04-15 20:00 ` Junio C Hamano
2016-04-24 19:51 ` Stephan Beyer
2016-04-25 18:08 ` Junio C Hamano
2016-04-10 13:18 ` [PATCH v2 04/21] t: use test_cmp_rev() where appropriate Stephan Beyer
2016-04-11 0:07 ` Eric Sunshine
2016-04-15 20:48 ` Junio C Hamano
2016-04-10 13:18 ` [PATCH v2 05/21] t6030: generalize test to not rely on current implementation Stephan Beyer
2016-04-10 13:47 ` Torsten Bögershausen
2016-04-10 19:16 ` Junio C Hamano
2016-04-10 19:37 ` Stephan Beyer
2016-04-11 0:23 ` Eric Sunshine
2016-04-15 21:07 ` Junio C Hamano
2016-04-10 13:18 ` [PATCH v2 06/21] bisect: add test for the bisect algorithm Stephan Beyer
2016-04-15 21:13 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 07/21] bisect: plug the biggest memory leak Stephan Beyer
2016-04-15 21:18 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 08/21] bisect: make bisect compile if DEBUG_BISECT is set Stephan Beyer
2016-04-15 21:22 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 09/21] bisect: make algorithm behavior independent of DEBUG_BISECT Stephan Beyer
2016-04-15 21:25 ` Junio C Hamano
2016-04-10 13:19 ` Stephan Beyer [this message]
2016-04-15 21:31 ` [PATCH v2 10/21] bisect: get rid of recursion in count_distance() Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 11/21] bisect: use struct node_data array instead of int array Stephan Beyer
2016-04-12 23:02 ` Christian Couder
2016-04-15 21:47 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 12/21] bisect: replace clear_distance() by unique markers Stephan Beyer
2016-04-12 23:20 ` Christian Couder
2016-04-15 22:07 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 13/21] bisect: use commit instead of commit list as arguments when appropriate Stephan Beyer
2016-04-15 22:08 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 14/21] bisect: extract get_distance() function from code duplication Stephan Beyer
2016-04-15 22:08 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 15/21] bisect: introduce distance_direction() Stephan Beyer
2016-04-15 22:10 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 16/21] bisect: make total number of commits global Stephan Beyer
2016-04-13 13:23 ` Christian Couder
2016-04-15 22:11 ` Junio C Hamano
2016-04-16 0:44 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 17/21] bisect: rename count_distance() to compute_weight() Stephan Beyer
2016-04-13 13:32 ` Christian Couder
2016-04-15 22:12 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 18/21] bisect: prepare for different algorithms based on find_all Stephan Beyer
2016-04-15 22:36 ` Junio C Hamano
2016-04-10 13:19 ` [PATCH v2 19/21] bisect: use a bottom-up traversal to find relevant weights Stephan Beyer
2016-04-13 14:11 ` Christian Couder
2016-04-15 22:47 ` Junio C Hamano
2016-04-15 22:49 ` Junio C Hamano
2016-04-26 18:27 ` Junio C Hamano
2016-04-10 13:24 ` [PATCH v2 20/21] bisect: compute best bisection in compute_relevant_weights() Stephan Beyer
2016-04-10 13:24 ` [PATCH v2 21/21] bisect: get back halfway shortcut Stephan Beyer
2016-04-15 22:53 ` Junio C Hamano
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