Re: Rebase performance

From: Stefan Beller <sbeller@google.com>
Date: Feb 25, 2016, 00:22 UTC
Message-ID: <CAGZ79kauMxxXcRu97CZ=uyau-fpNpZ-8q8vM5fDRmUmuLaMLPw@mail.gmail.com>
In-Reply-To: <CA+P7+xpC+gZijkcxcp8uFCmYjQf7-0xbBf7FWSsFnMXB1b7G+Q@mail.gmail.com>

On Wed, Feb 24, 2016 at 4:15 PM, Jacob Keller <jacob.keller@gmail.com> wrote:

Show 21 quoted lines

> On Wed, Feb 24, 2016 at 2:09 PM, Christian Couder
> <christian.couder@gmail.com> wrote:
>> Hi,
>> Another possibility would be to libify the "git apply" functionality
>> and then to use the libified "git apply" in run_apply() instead of
>> launching a separate "git apply" process. One benefit from this is
>> that we could probably get rid of the read_cache_from() call at the
>> end of run_apply() and this would likely further speed up things. Also
>> avoiding to launch separate processes might be a win especially on
>> Windows.
>>
>
> This is the route I would go, since the addition of a taskset option
> seems pretty difficult to get correct, and may not be portable. This
> above solution likely improves more in general, and is more portable.
> Not exactly sure how easy it would be to "libify" the required bits of
> apply, however.. it may be that this is already available as well but
> we just didn't go that route during the port of git-am into C code.
>
> Regards,
> Jake

IIRC Junio started libifying am after Paul Tan rewrote it in C, See origin/jc/am-mailinfo-direct (tip at 4b98bae2cbc6b).

That part however only libifyies the mailinfo which is used by apply (one layer below), so I am not sure if the run_apply has been attempted to libify.

I would also encourage to rather try to not call out to a child (libifying) instead of adding the taskset hack for servers.

Thanks, Stefan

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