redhat/kernel.spec.template: Parallelize compression

Bugzilla: INTERNAL
Upstream Status: RHEL only

commit 7f5f91411c41096fff0b86718584363dd910cd6b
Author: Prarit Bhargava <prarit@redhat.com>
Date:   Sat Jan 21 07:54:21 2023 -0500

    redhat/kernel.spec.template: Parallelize compression

    This line in the kernel.spec file:

    find $RPM_BUILD_ROOT/lib/modules/ -type f -name '*.ko' | xargs -P${RPM_BUILD_NCPUS} -r xz;

    implies that ${RPM_BUILD_NCPUS} xz instances are run.  This is not true,
    and this line actually applies ${RPM_BUILD_NCPUS} to a single instance of
    xz.  This means that the compression has been done one module at a time
    (ie, in serial) rather than in parallel as is implied by the code.

    Use xarg's -n option to assign 16 cpus per process and parallelize the
    compression.

    Suggested-by: "Herton R. Krzesinski" <herton@redhat.com>
    Signed-off-by: Prarit Bhargava <prarit@redhat.com>

Signed-off-by: Herton R. Krzesinski <herton@redhat.com>

Author: Herton R. Krzesinski

redhat/kernel.spec.template

@@ -2594,7 +2594,8 @@ find Documentation -type d | xargs chmod u+w
     fi \
   fi \
   if [ "%{zipmodules}" -eq "1" ]; then \
-    find $RPM_BUILD_ROOT/lib/modules/ -type f -name '*.ko' | xargs -P${RPM_BUILD_NCPUS} -r xz; \
+    echo "Compressing kernel modules ..." \
+    find $RPM_BUILD_ROOT/lib/modules/ -type f -name '*.ko' | xargs -n 16 -P${RPM_BUILD_NCPUS} -r xz; \
   fi \
 %{nil}