Messages in this thread | | | Subject | Re: linux/Makefile: CONFIG_SHELL and SHELL | From | Andreas Schwab <> | Date | 01 Sep 1998 11:29:44 +0200 |
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Clifford Wolf <clifford@clifford.at> writes:
|> On 31 Aug 1998, Andreas Schwab wrote: |> |> > Clifford Wolf <clifford@clifford.at> writes: |> > |> > |> At the top of the Makefile we set the variable CONFIG_SHELL which than |> > |> should be a bash (if possible). Why don't setting the variable SHELL to |> > |> the value of CONFIG_SHELL? If we need bash features we should force to |> > |> use bash - or don't use bash features. |> > |> > Please do the latter. Setting SHELL to a nonstandard value (different |> > from /bin/sh) causes *all* commands to be started with '$(SHELL) -c cmd' |> > instead of internally by make (which knows about the /bin/sh parsing |> > rules). That would kill performance quite a bit. |> |> I don't know much about the internals of GNU make - and I'm sure you are |> right in theory - but this are the values I got: |> |> with "SHELL := $(CONFIG_SHELL)": |> |> real 13m32.125s |> user 12m20.000s |> sys 0m46.000s |> |> without "SHELL := $(CONFIG_SHELL)": |> |> real 13m14.745s |> user 12m18.910s |> sys 0m45.030s
It depends on whether /bin/sh can be kept cached while the compiler is running. If it needs to be loaded from disk each time then the difference is noticable.
-- Andreas Schwab "And now for something schwab@issan.informatik.uni-dortmund.de completely different" schwab@gnu.org
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