build: fix race condition building enam.o

build: fix race condition building enam.o

[dave_cheney.net, 2011-03-01 10:48:42]

Under high concurrency, MAKEFLAGS=-j16 on a large machine there is a race
condition between $(O)a and ($O)l building $(O)l/enam.o

This patch restores the original ordering from make.bash that was removed in CL
4221047.

[rsc, 2011-03-01 12:54:52]

please drop the blank lines between dependency-only rules.

shouldn't the new rule be

$(O)a.install $(O)c.install $(O)g.install: $(O)l.install

?


On Tue, Mar 1, 2011 at 05:48,  <dave@cheney.net> wrote:
> Reviewers: golang-dev_googlegroups.com,
>
> Message:
> Under high concurrency, MAKEFLAGS=-j16 on a large machine there is a
> race condition between $(O)a and ($O)l building $(O)l/enam.o
>
> This patch restores the original ordering from make.bash that was
> removed in CL 4221047.
>
> Description:
> build: fix race condition building enam.o
>
> Please review this at http://codereview.appspot.com/4240055/
>
> Affected files:
>  M src/cmd/Makefile
>
>
> Index: src/cmd/Makefile
> ===================================================================
> --- a/src/cmd/Makefile
> +++ b/src/cmd/Makefile
> @@ -61,6 +61,8 @@
>
>  $(O)g.install: gc.install
>
> +$(O)a.install: $(O)l.install
> +
>  %.clean:
>        $(MAKE) -C $* clean
>
>
>
>

[dave_cheney.net, 2011-03-01 13:14:04]

On 2011/03/01 12:54:52, rsc wrote:
> please drop the blank lines between dependency-only rules.

Done.
 
> shouldn't the new rule be
> 
> $(O)a.install $(O)c.install $(O)g.install: $(O)l.install

Yes, thank you for spotting that.

Please take another look

[rsc, 2011-03-02 18:46:45]

LGTM

[rsc, 2011-03-02 19:22:41]

*** Submitted as 8bbb099b8547 ***

build: fix race condition building enam.o

R=golang-dev, rsc
CC=albert.strasheim, golang-dev
http://codereview.appspot.com/4240055

Committer: Russ Cox <rsc@golang.org>