list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: Ramsay Jones <>
To: Junio C Hamano <>
Cc: GIT Mailing-list <>
Subject: Re: [PATCH 2/8] Documentation/Makefile: conditionally include ../GIT-VERSION-FILE
Date: Fri, 6 Nov 2020 01:30:30 +0000	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 05/11/2020 21:52, Junio C Hamano wrote:
> Ramsay Jones <> writes:
>> The 'clean' target is still noticeably slow on cygwin, despite the
>> substantial improvement made by the previous patch. For example, the
>> second invocation of 'make clean' below:
>>   $ make clean >/dev/null 2>&1
>>   $ make clean
>>   ...
>>   make[1]: Entering directory '/home/ramsay/git/Documentation'
>>   make[2]: Entering directory '/home/ramsay/git'
>>   make[2]: 'GIT-VERSION-FILE' is up to date.
>>   make[2]: Leaving directory '/home/ramsay/git'
>>   ...
>>   $
>> has been timed at 12.364s on my laptop (on old core i5-4200M @ 2.50GHz,
>> 8GB RAM, 1TB HDD).
>> Notice that the 'clean' target is making a nested call to the parent
>> Makefile to ensure that the GIT-VERSION-FILE is up-to-date (prior to
>> the previous patch, there would have been _two_ such invocations).
>> This is to ensure that the $(GIT_VERSION) make variable is set, once
>> that file had been included.  However, the 'clean' target does not use
>> the $(GIT_VERSION) variable, so this is wasted effort.
>> In order to eliminate such wasted effort, use the value of the internal
>> $(MAKECMDGOALS) variable to only '-include ../GIT-VERSION-FILE' when the
>> target is not 'clean'. (This drops the time down to 10.361s, on my laptop,
>> giving an improvement of 16.20%).
> This obviously relies on the fact that none of our build products to
> be cleaned are named using $(GIT_VERSION)---in other words, if our
> cleaning rule contained
> 	rm -f git-$(GIT_VERSION)-manual.html
> this optimization would not work well.

Yes, indeed.

> Luckily, I think we use GIT_VERSION only to engrave version number
> in the resulting document, and it does not affect the name of the
> build product, so this change is safe, I think.

Yes, as I said in the commit message above:

    "However, the 'clean' target does not use
    the $(GIT_VERSION) variable, so this is wasted effort."


Ramsay Jones

  reply	other threads:[~2020-11-06  1:30 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-05 21:03 Ramsay Jones
2020-11-05 21:52 ` Junio C Hamano
2020-11-06  1:30   ` Ramsay Jones [this message]
2020-11-06 18:18 ` Jeff King
2020-11-06 19:38   ` Ramsay Jones
2020-11-06 20:56     ` Jeff King
2020-11-06 21:43     ` Junio C Hamano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

  List information:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \
    --subject='Re: [PATCH 2/8] Documentation/Makefile: conditionally include ../GIT-VERSION-FILE' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Code repositories for project(s) associated with this inbox:

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).