From: Derrick Stolee <stolee@gmail.com>
Date: Sun, 25 Feb 2018 01:41:02 GMT
Subject: Re: [PATCH] revision.c: reduce object database queries
Message-ID: <e70fe6eb-994a-66b0-3c20-d19ea6635e07@gmail.com>
In-Reply-To: <1519522496-73090-1-git-send-email-dstolee@microsoft.com>

On 2/24/2018 8:34 PM, Derrick Stolee wrote:
> In mark_parents_uninteresting(), we check for the existence of an
> object file to see if we should treat a commit as parsed. The result
> is to set the "parsed" bit on the commit.
>
> Modify the condition to only check has_object_file() if the result
> would change the parsed bit.
>
> When a local branch is different from its upstream ref, "git status"
> will compute ahead/behind counts. This uses paint_down_to_common()
> and hits mark_parents_uninteresting(). On a copy of the Linux repo
> with a local instance of "master" behind the remote branch
> "origin/master" by ~60,000 commits, we find the performance of
> "git status" went from 1.42 seconds to 1.32 seconds, for a relative
> difference of -7.0%.

I do want to add that the exact same "git status" performance test with 
the commit-graph feature goes from 0.29 seconds to 0.21 seconds for a 
relative change of -27.5%.

Thanks,

-Stolee