Re: [HACKERS] Compile timing

> Not sure why -j2 is not faster than normal -j...

I was just looking at this a little while ago at work. It is not
faster because gmake does not propagate the "-j2" flag to submakes, on
the (correct) theory that you might get a geometrically growing system
load, rather than just keeping two makes running through all the
subdirectories.

This is the behavior of "-j", unless you specify it without a numeric
parameter, in which case it *does* allow parallel submakes.

The first time I tried "-j", I did it without reading the man pages
and without specifying a numeric parameter. It did a magnificent job
of bringing down my system trying to build ACE/TAO, a *large* Corba
package. Chewed up all of real memory, then all of swap; not sure if I
ran out of process slots or memory first but it wasn't pretty. It was
*very* fast though :)

- Thomas

--
Thomas Lockhart lockhart(at)alumni(dot)caltech(dot)edu
South Pasadena, California