From: Dan McGee <dpmcgee@gmail.com>
To: git@vger.kernel.org
Cc: Dan McGee <dpmcgee@gmail.com>
Subject: [PATCH 3/5] tree-walk: micro-optimization in tree_entry_interesting
Date: Wed, 30 Mar 2011 20:37:59 -0500 [thread overview]
Message-ID: <1301535481-1085-3-git-send-email-dpmcgee@gmail.com> (raw)
In-Reply-To: <1301535481-1085-1-git-send-email-dpmcgee@gmail.com>
In the case of a wide breadth top-level tree (~2400 entries, all trees
in this case), we can see a noticeable cost in the profiler calling
strncmp() here. Most of the time we are at the base level of the
repository, so base is "" and baselen == 0, which means we will always
test true. Break out this one tiny case so we can short circuit the
strncmp() call.
This resulted in an ~11% improvement (43 to 38 secs) for a reasonable
log operation on the Arch Linux Packages SVN clone repository, which
contained 117220 commits and the aforementioned 2400 top-level objects:
git log -- autogen/trunk pacman/trunk/ wget/trunk/
Negligible slowdown was noted with other repositories (e.g. linux-2.6).
Signed-off-by: Dan McGee <dpmcgee@gmail.com>
---
tree-walk.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/tree-walk.c b/tree-walk.c
index 9be8007..f386151 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -591,8 +591,8 @@ int tree_entry_interesting(const struct name_entry *entry,
ps->max_depth);
}
- /* Does the base match? */
- if (!strncmp(base_str, match, baselen)) {
+ /* Either there must be no base, or the base must match. */
+ if (baselen == 0 || !strncmp(base_str, match, baselen)) {
if (match_entry(entry, pathlen,
match + baselen, matchlen - baselen,
&never_interesting))
--
1.7.4.2
next prev parent reply other threads:[~2011-03-31 1:38 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-31 1:37 [PATCH 1/5] diff_tree_sha1: skip diff_tree if old == new Dan McGee
2011-03-31 1:37 ` [PATCH 2/5] tree-walk: drop unused parameter from match_dir_prefix Dan McGee
2011-08-30 18:55 ` Dan McGee
2011-03-31 1:37 ` Dan McGee [this message]
2011-04-03 4:01 ` [PATCH 3/5] tree-walk: micro-optimization in tree_entry_interesting Nguyen Thai Ngoc Duy
2011-04-03 18:55 ` Junio C Hamano
2011-04-05 0:22 ` Dan McGee
[not found] ` <CAEik5nOKrpFycZYVnSu4_5LYWxn0JS_hVXyiQH-80Bu-C4k8VQ@mail.gmail.com>
2011-08-30 19:51 ` Dan McGee
2011-08-30 20:40 ` Junio C Hamano
2011-09-09 2:02 ` [PATCH 1/2] tree-walk: drop unused parameter from match_dir_prefix Dan McGee
2011-09-09 2:02 ` [PATCH 2/2] tree-walk: micro-optimization in tree_entry_interesting Dan McGee
2011-04-04 14:46 ` [PATCH] tree_entry_interesting: inline strncmp() Nguyễn Thái Ngọc Duy
2011-03-31 1:38 ` [PATCH 4/5] tree-walk: unroll get_mode since loop boundaries are well-known Dan McGee
2011-04-02 9:28 ` Nguyen Thai Ngoc Duy
2011-04-02 17:28 ` Dan McGee
2011-04-03 4:07 ` Nguyen Thai Ngoc Duy
2011-04-04 10:29 ` Erik Faye-Lund
2011-04-04 12:30 ` Andreas Ericsson
2011-04-04 16:55 ` Junio C Hamano
2011-04-05 5:33 ` Dan McGee
2011-04-05 23:55 ` Antriksh Pany
2011-04-06 20:45 ` Dan McGee
2011-03-31 1:38 ` [PATCH 5/5] tree-walk: match_entry microoptimization Dan McGee
2011-04-02 9:06 ` Nguyen Thai Ngoc Duy
2011-04-02 17:54 ` Dan McGee
2011-03-31 12:58 ` [PATCH 1/5] diff_tree_sha1: skip diff_tree if old == new Nguyen Thai Ngoc Duy
2011-03-31 13:56 ` Dan McGee
2011-04-01 22:28 ` Junio C Hamano
[not found] ` <AANLkTinPSqDPdGi5nA3sH1D2wMSW1SQc+5gRqdLy++y0@mail.gmail.com>
2011-04-02 18:38 ` Fwd: " Dan McGee
2011-05-03 7:34 ` Nguyen Thai Ngoc Duy
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