friedl@mtndew.UUCP (Stephen J. Friedl) (07/10/90)
Hi folks,
In my Allegely Portable Software Package, my focus has turned
onto makefiles. Some machines support a parallel make facility, and
I would rather this it than not use it, but I don't know how common
the syntax is. Sequent uses the notation:
target : & file1.o file2.o file3.o
commands
where the & marks the start of the dependencies that can be
parallelized (BSD make only, not in the Sys V make).
What other notations are out there? I already have a
front-end to make that can take care of some of this syntax
difference by sticking macros on the command line, but I
gotta know where to start.
Steve
--
Stephen J. Friedl, KA8CMY / Software Consultant / Tustin, CA / 3B2-kind-of-guy
+1 714 544 6561 / friedl@mtndew.Tustin.CA.US / {uunet,attmail}!mtndew!friedl
Berkeley UNIX is for people who don't have real work to doprc@erbe.se (Robert Claeson) (07/11/90)
In article <464@mtndew.UUCP>, friedl@mtndew.UUCP (Stephen J. Friedl) writes: > In my Allegely Portable Software Package, my focus has turned > onto makefiles. Some machines support a parallel make facility, and > I would rather this it than not use it, but I don't know how common > the syntax is. Sequent uses the notation: > target : & file1.o file2.o file3.o > commands I'm "quite" familiar (read: use it daily) with the parallel make that Encore Computer Corp. ships with their o/s'es (BSD 4.3, SysV R3.2, Mach) for the Multimax computers. The sequential make is named "make" and the parallel one has the name "pmake" (I believe that there's a PD parallel make that's also named "pmake"). Pmake doesn't require any modifications to a well-written makefile. It recognizes when compiles aren't depending on each other and runs them in parallel. The number of compiles that can be performed simultaneously is determined by the environment variable "PARALLEL", or via a command-line switch. If not given, a default of 3 is used. Just make sure that all dependencies are explicitly defined in the makefile. Don't rely on that a sequential make will run them in the right order, it might not work with a parallel make, which can otherwise start to link a program before all source files that belongs to it are compiled. -- Robert Claeson |Reasonable mailers: rclaeson@erbe.se ERBE DATA AB | Dumb mailers: rclaeson%erbe.se@sunet.se | Perverse mailers: rclaeson%erbe.se@encore.com These opinions reflect my personal views and not those of my employer (ask him).
bob@MorningStar.Com (Bob Sutterfield) (07/12/90)
GNU Make, when invoked with the -j<number> option, will do up to <number> tasks in parallel. Rather than requiring a novel Makefile syntax, it deduces independent tasks from a well-written but otherwise normal Makefile. Once forked by the Makefile, tasks are subject to the operating system's normal process scheduler. It can perform some tasks in parallel, then a few in serial, then some more in parallel, if the dependencies are appropriate. For example, `gmake -j7 libXt.a' is about right for a Sun-4/60 with 16Mb, plenty of swap space, and nothing else to do. If your CC is gcc and your CFLAGS include -pipe, you may want to back down to -j4 or so.