Eric Bavier <ericbav...@centurylink.net> skribis:
> On Sun, 22 Oct 2017 19:51:14 -0700
> l...@gnu.org (Ludovic Courtès) wrote:
[...]
>> > It Would Be Nice if the functionality worked for older versions of make
>> > that people might have on their systems.
>>
>> With the patch I posted, Scheme compilation would always use one thread
>> per core, which is what it currently does in ‘master’.
Oops, that was not quite true: it would use one thread.
I fixed it like this:
diff --git a/build-aux/compile-all.scm b/build-aux/compile-all.scm
index 4aa4ac9b9..c7ca5a6f6 100644
--- a/build-aux/compile-all.scm
+++ b/build-aux/compile-all.scm
@@ -19,6 +19,7 @@
(use-modules (ice-9 match)
(ice-9 threads)
+ (srfi srfi-1)
(guix build compile)
(guix build utils))
@@ -50,24 +51,32 @@ to 'make'."
(match flags
(#f (current-processor-count))
(flags
- (let loop ((flags (string-tokenize flags)))
- (match flags
- (()
- 1)
- (("-j" (= string->number count) _ ...)
- (if (integer? count)
- count
- (current-processor-count)))
- ((head tail ...)
- (if (string-prefix? "-j" head)
- (match (string-drop head 2)
- (""
- (current-processor-count))
- ((= string->number count)
- (if (integer? count)
- count
- (current-processor-count))))
- (loop tail))))))))
+ (let ((initial-flags (string-tokenize flags)))
+ (let loop ((flags initial-flags))
+ (match flags
+ (()
+ ;; Note: GNU make prior to version 4.2 would hide "-j" flags from
+ ;; $MAKEFLAGS. Thus, check for a "--jobserver" flag here and
+ ;; assume we're using all cores if specified.
+ (if (any (lambda (flag)
+ (string-prefix? "--jobserver" flag))
+ initial-flags)
+ (current-processor-count) ;GNU make < 4.2
+ 1)) ;sequential make
+ (("-j" (= string->number count) _ ...)
+ (if (integer? count)
+ count
+ (current-processor-count)))
+ ((head tail ...)
+ (if (string-prefix? "-j" head)
+ (match (string-drop head 2)
+ (""
+ (current-processor-count))
+ ((= string->number count)
+ (if (integer? count)
+ count
+ (current-processor-count))))
+ (loop tail)))))))))
;; Install a SIGINT handler to give unwind handlers in 'compile-file' an
;; opportunity to run upon SIGINT and to remove temporary output files.
>> > Using the jobserver directly would require quite a bit of work for the
>> > current patch set, but I wonder if there is another way to determine
>> > the -jN parameter for make<4.2 that we could use. Maybe simply
>> > polling the jobserver fds at the start?
>>
>> AIUI the job server does not reveal how many jobs are allowed. It
>> merely grants you an execution token.
>>
>> Or did you have something else in mind?
>
> The idea (hardely tested) would be to read tokens from the input fd
> until it blocks, do the scheme compiles with however many tokens were
> read, then write them back out. Crude, I guess, and probably error
> prone; compile-all.scm could be invoked when make has job tokens tied
> up building the daemon source...
>
> Anyhow, the current patch works well for me with a recent make. I'm
> content leaving further improvements to a future hypothetical hacker. :)
Sounds reasonable. Let’s make sure the hypothetical hacker has enough
on their plate. :-)
I’ve pushed this and the easy parts of this patch series, with commit
d298c815e638581d466222f3a883b280f019b368 as the tip.
Thanks for the review!
Ludo’.
