Re: what is the minimal version of make supported for building the kernel?

[Jim Davis]

On Mon, Jun 20, 2016 at 5:15 AM, Robert P. J. Day  wrote:

>   now, Documentation/Changes currently does indeed state:
>
> Current Minimal Requirements
> 
> ... snip ...
> o  GNU make   3.80# make --version
>
> but i did a quick grep to find:
>
>   $ grep -r "else ifeq" *
>   lib/raid6/test/Makefile:else ifeq ($(HAS_NEON),yes)
>   $
>
> so would that single test not violate the rule just described above?
> is Documentation/Changes entirely up to date with respect to minimal
> requirements?

Probably not.  Checking with the latest 4.x and 3.x stable releases,
on a CentOS 5.11 i386 VM with 4GB of RAM,  'make defconfig' fails in
4.6.3 using make 3.80:

make[1]: *** virtual memory exhausted.  Stop.

which looks like a bug that was fixed in 3.81.  'make defconfig' using
make 3.80 works with 3.14.73, but curiously 'make distclean' then
fails with

Extraneous text after 'else' directive

in kernel/gcov/Makefile.

As make 3.80 dates from 2002... it might be time to bump the minimum
required make version up to 3.81 (which is only ten years old now).

-- 
Jim

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

what is the minimal version of make supported for building the kernel?

[Robert P. J. Day]

  another curiosity related to my current travels through the
initramfs code, i noticed this git commit from back in 2013:

$ git show 7ac1815683
commit 7ac181568342ec618d4da1ab03c2babcaa7ee84f
Author: Jan Beulich 
Date:   Wed Dec 18 17:08:57 2013 -0800

fix build with make 3.80

According to Documentation/Changes, make 3.80 is still being supported
for building the kernel, hence make files must not make (unconditional)
use of features introduced only in newer versions.

Commit 1bf49dd4be0b ("./Makefile: export initial ramdisk compression
config option") however introduced "else ifeq" constructs which make
3.80 doesn't understand.  Replace the logic there with more conventional
(in the kernel build infrastructure) list constructs (except that the
list here is intentionally limited to exactly one element).

Signed-off-by: Jan Beulich 
Cc: P J P 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 

diff --git a/Makefile b/Makefile
index 858a147..89cee86 100644
--- a/Makefile
+++ b/Makefile
@@ -732,19 +732,13 @@ export mod_strip_cmd
 # Select initial ramdisk compression format, default is gzip(1).
 # This shall be used by the dracut(8) tool while creating an
initramfs image.
 #
-INITRD_COMPRESS=gzip
-ifeq ($(CONFIG_RD_BZIP2), y)
-INITRD_COMPRESS=bzip2
-else ifeq ($(CONFIG_RD_LZMA), y)
-INITRD_COMPRESS=lzma
-else ifeq ($(CONFIG_RD_XZ), y)
-INITRD_COMPRESS=xz
-else ifeq ($(CONFIG_RD_LZO), y)
-INITRD_COMPRESS=lzo
-else ifeq ($(CONFIG_RD_LZ4), y)
-INITRD_COMPRESS=lz4
-endif
-export INITRD_COMPRESS
+INITRD_COMPRESS-y  := gzip
+INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
+INITRD_COMPRESS-$(CONFIG_RD_LZMA)  := lzma
+INITRD_COMPRESS-$(CONFIG_RD_XZ):= xz
+INITRD_COMPRESS-$(CONFIG_RD_LZO)   := lzo
+INITRD_COMPRESS-$(CONFIG_RD_LZ4)   := lz4
+export INITRD_COMPRESS := $(INITRD_COMPRESS-y)

... etc etc ...

  now, Documentation/Changes currently does indeed state:

Current Minimal Requirements

... snip ...
o  GNU make   3.80# make --version

but i did a quick grep to find:

  $ grep -r "else ifeq" *
  lib/raid6/test/Makefile:else ifeq ($(HAS_NEON),yes)
  $

so would that single test not violate the rule just described above?
is Documentation/Changes entirely up to date with respect to minimal
requirements?

rday

-- 


Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca

Twitter:   http://twitter.com/rpjday
LinkedIn:   http://ca.linkedin.com/in/rpjday



___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies