build-system: linux-module: Build and install in parallel.

* guix/build-system/linux-module.scm (linux-module-build)
(guix/build-system/linux-module.scm): Accept the PARALLEL-BUILD? keyword
and pass it on to the builder.
* guix/build/linux-module-build-system.scm (build, install): Capture and
honour it.

2 files changed, 19 insertions, 6 deletions

diff --git a/guix/build-system/linux-module.scm b/guix/build-system/linux-module.scm
index 33bc8c95df..548ed7a9aa 100644
--- a/guix/build-system/linux-module.scm
+++ b/guix/build-system/linux-module.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2019 Danny Milosavljevic <dannym@scratchpost.org>
 ;;; Copyright © 2020 Mathieu Othacehe <m.othacehe@gmail.com>
+;;; Copyright © 2021 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -157,6 +158,7 @@
                                          %standard-phases))
                              (outputs '("out"))
                              (make-flags ''())
+                             (parallel-build? #t)
                              (system (%current-system))
                              (source-directory ".")
                              (guile #f)
@@ -187,6 +189,7 @@
                      #:tests? ,tests?
                      #:outputs %outputs
                      #:make-flags ,make-flags
+                     #:parallel-build? ,parallel-build?
                      #:inputs %build-inputs)))
 
   (define guile-for-build
@@ -213,6 +216,7 @@
           (guile #f)
           (outputs '("out"))
           (make-flags ''())
+          (parallel-build? #t)
           (search-paths '())
           (native-search-paths '())
           (tests? #f)
diff --git a/guix/build/linux-module-build-system.scm b/guix/build/linux-module-build-system.scm
index 1541b6393e..7c0dba8445 100644
--- a/guix/build/linux-module-build-system.scm
+++ b/guix/build/linux-module-build-system.scm
@@ -50,16 +50,22 @@
   ; TODO: kernel ".config".
   #t)
 
-(define* (build #:key inputs make-flags (source-directory ".") #:allow-other-keys)
+(define* (build #:key (make-flags '()) (parallel-build? #t)
+                (source-directory ".")
+                inputs
+                #:allow-other-keys)
   (apply invoke "make" "-C"
          (string-append (assoc-ref inputs "linux-module-builder")
                         "/lib/modules/build")
          (string-append "M=" (canonicalize-path source-directory))
-         (or make-flags '())))
+         `(,@(if parallel-build?
+                 `("-j" ,(number->string (parallel-job-count)))
+                 '())
+           ,@make-flags)))
 
-;; This block was copied from make-linux-libre--only took the "modules_install"
-;; part.
-(define* (install #:key make-flags (source-directory ".")
+;; Similar to the "modules_install" part of make-linux-libre.
+(define* (install #:key (make-flags '()) (parallel-build? #t)
+                  (source-directory ".")
                   inputs native-inputs outputs
                   #:allow-other-keys)
   (let* ((out (assoc-ref outputs "out"))
@@ -80,7 +86,10 @@
             (string-append "INSTALL_MOD_PATH=" out)
             "INSTALL_MOD_STRIP=1"
             "modules_install"
-            (or make-flags '()))))
+         `(,@(if parallel-build?
+                 `("-j" ,(number->string (parallel-job-count)))
+                 '())
+           ,@make-flags))))
 
 (define %standard-phases
   (modify-phases gnu:%standard-phases