From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 28 Aug 2012 21:35:03 GMT
Subject: Re: [PATCH 5/5] (BROKEN) get_merge_bases_many(): walk from many tips in parallel
Message-ID: <7v8vcyzomw.fsf@alter.siamese.dyndns.org>
In-Reply-To: <7vipc3q041.fsf@alter.siamese.dyndns.org>

Junio C Hamano <gitster@pobox.com> writes:

> Junio C Hamano <gitster@pobox.com> writes:
>
>>  	for (i = 0; i < cnt; i++) {
>> -		if (rslt[i])
>> +		/*
>> +		 * Is rslt[i] an ancestor of any of the others?
>> +		 * then it is not interesting to us.
>> +		 */
>> +		for (j = 0; j < i; j++)
>> +			others[j] = rslt[j];
>> +		for (j = 1 + 1; j < cnt; j++)
>
> s/1 + 1/i + 1/;
>
> With that, all tests seem to pass ;-)

"git merge-base" itself seems to have more room for improvement.
Trying to recompute bases for recent 200 merges in the kernel
history with the attached script does not show any improvement with
or without the series on top of recent "master".  Correctnesswise it
seems to be OK, though---I get byte-for-byte identical output.

-- >8 --
#!/bin/sh

git rev-list --committer=torvalds@linux-foundation.org \
    --max-parents=2 --min-parents=2 --parents v3.5..v3.6-rc2 >RL

cmd='
	while read result parent1 parent2
	do
		$GIT merge-base $parent1 $parent2
	done <RL
'

GIT="rungit master" time sh -c "$cmd" >:stock
GIT=../git.git/git time sh -c "$cmd" >:optim
cmp :stock :optim
-- 8< --