Re: [Automake-NG] [PATCH 00/11] Several changes to parallel-tests support

[Bob Friesenhahn]

On Thu, 10 May 2012, Stefano Lattarini wrote:
> ===================================
> BEFORE the series is been applied
> ===================================
>
> $ make all                                      # 12 times
> 1.5 seconds
>
> ===================================
> AFTER the series has been applied
> ===================================
>
> $ make all                                      # 12 times
> 10 seconds
>
> These numbers are still acceptable IMHO, and are a price worth to paying
> for the improved cleanliness of the code.

10 seconds would not be at all acceptable to me.  To me classic 
Automake 'make all' "NOP" time is already 2X what it should be for my 
package due to the recursion (just over a second, or 1/2 a second, 
depending on the machine).

Building the whole package might take 40 seconds, and the time is 
primarily to blame on the compiler.  A typical case is to edit a 
single source file and type 'make'.  This typical case needs to be as 
optimized as possible.  Parsing and evaluating the Makefile should be 
a fraction of the time required to run the compiler on one source 
module and re-link.

> So, in conclusion: while I think we should keep an eye on performance,
> I believe this series should be merged as-is, and optimizations should
> be done later (once we'll have more framework about variable handling
> in place).
>
> WDYT?

There is some concern about corner-painting.  There needs to be a plan 
to avoid being painted into a corner without hope of restoring the 
performance which was lost.

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/