From: ZheNing Hu <adlternative@gmail.com>
To: Christian Couder <christian.couder@gmail.com>
Cc: "Git List" <git@vger.kernel.org>,
"Junio C Hamano" <gitster@pobox.com>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Hariom verma" <hariom18599@gmail.com>
Subject: Re: [GSoC] Git Blog 12
Date: Wed, 11 Aug 2021 11:47:27 +0800 [thread overview]
Message-ID: <CAOLTT8S0etdnFNKuD7z5QMxWdERZ-FWimn4Sc+u+7Ra1F2WAmA@mail.gmail.com> (raw)
In-Reply-To: <CAOLTT8TQxz2xkQE7etDa3cgb-kRfho-WAyhfHTsK=FrYVsPN1A@mail.gmail.com>
ZheNing Hu <adlternative@gmail.com> 于2021年8月10日周二 下午10:20写道:
>
> Christian Couder <christian.couder@gmail.com> 于2021年8月10日周二 下午4:04写道:
>
> > > parse_object_buffer(), let's take a look at the result of gprof again:
> > >
> > > We need to call grab_sub_body_contents(), grab_person() to rescan the
> > > buffer and extract the data.
> > > What if we can combine these multiple scanning and parsing into one completion?
> > > At least intuitively, this has an opportunity to improve performance.
> >
> > Yeah, but is there a way to check that we indeed scan or parse the
> > same objects multiple times? This way we might get an idea about how
> > much scanning and parsing we could save.
> >
>
> I think find_subpos() called by grab_sub_body_contents() and find_wholine()
> called by grab_person() are evidences that we are repeating iteratively.
> But the proportion of time they occupy is too small. 0.0142% and 0.0109%
>
Using such a method may reduce some unnecessary scans [1]
But it can do very little optimization... 1.6%.
On the other hand, our optimization should focus on the default format of
`git cat-file --batch`.
My new idea is to need a fast path: when we use the default format,
let us directly execute get_object() to avoid unnecessary traversal
and checking.
Thanks,
--
ZheNing Hu
[1]: https://github.com/adlternative/git/commit/7d274971d2b5e1d4e6061d1e29e4a0b2c6a10ea5
next prev parent reply other threads:[~2021-08-11 3:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-09 5:56 [GSoC] Git Blog 12 ZheNing Hu
2021-08-10 8:04 ` Christian Couder
2021-08-10 14:20 ` ZheNing Hu
2021-08-11 3:47 ` ZheNing Hu [this message]
2021-08-11 8:20 ` Christian Couder
2021-08-13 8:25 ` ZheNing Hu
2021-08-11 8:15 ` Christian Couder
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