Roger Strain <rstrain@xxxxxxxx> writes: > After testing a previous patch at larger scale, a performance issue was > detected when using git show to locate parent revisions, with a single > run of the git show command taking 2 seconds or longer in a complex repo. > When the command is required tens or hundreds of times in a run of the > script, the additional wait time is unaccepatable. Replacing the command > with git rev-parse resulted in significantly increased performance, with > the command in question returning instantly. > > Signed-off-by: Roger Strain <rstrain@xxxxxxxx> > Thanks-to: Junio C Hamano <gitster@xxxxxxxxx> That usually is spelled as "Helped-by:". Will queue. Thanks. I still find it disturbing not to know why "show -s --format=..." takes measurable time, though. "-s" means "we do not need any diff output", so it ought to be comparable to "git cat-file commit $rev" with some formatting, but apparently your repository is making Git spend a lot more than that. Puzzled... > --- > contrib/subtree/git-subtree.sh | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh > index 1c157dbd9..147201dc6 100755 > --- a/contrib/subtree/git-subtree.sh > +++ b/contrib/subtree/git-subtree.sh > @@ -633,7 +633,7 @@ process_split_commit () { > else > # processing commit without normal parent information; > # fetch from repo > - parents=$(git show -s --pretty=%P "$rev") > + parents=$(git rev-parse "$rev^@") > extracount=$(($extracount + 1)) > fi