xz kernel modules (Re: [packages/kernel] - updated config)

[Elan Ruusamäe]

On 13.12.2014 12:46, Jan Rękorajski wrote:
> On Thu, 11 Dec 2014, Elan Ruusamäe wrote:
>
>> On 10.12.2014 21:59, Jan Rękorajski wrote:
>>> What about switching to xz? That will require recent kmod, but we do it
>>> only for 3.18+ and if someone is running fresh kernel we can assume he
>>> has a fresh userspace.
>> i see you already switched. would be nice to see some du stats before
>> and after
> [root at home 3.17.2-1]# du -hs kernel*
> 54M	kernel.gz
> 46M	kernel.xz
>
> ~20% savings.
you compressed the files yourself?

because our rpm build automation does not strip the files:

[~/tmp/kernel-3.18.3-root-glen/lib] ➔ dus */
   1.  modules/  112.95 MiB
   2. firmware/    2.46 MiB
Total:             115.41 MiB


[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ l 
fs/xfs/xfs.ko.xz
-rw-r--r-- 1 glen users 702K 26. jaan  21:42 fs/xfs/xfs.ko.xz
[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ xz -d 
fs/xfs/xfs.ko.xz
[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ file 
fs/xfs/xfs.ko
fs/xfs/xfs.ko: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), 
BuildID[sha1]=63b5e04025bf63f7cd892e1f71785a0aa575fd28, not stripped


[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ strip 
fs/xfs/xfs.ko
[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ file 
fs/xfs/xfs.ko
fs/xfs/xfs.ko: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), 
BuildID[sha1]=63b5e04025bf63f7cd892e1f71785a0aa575fd28, stripped

[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ l 
fs/xfs/xfs.ko
-rw-r--r-- 1 glen users 723K 26. jaan  21:58 fs/xfs/xfs.ko

[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ xz -9 
fs/xfs/xfs.ko
xz: Adjusted the number of threads from 4 to 3 to not exceed the memory 
usage limit of 4,773 MiB
[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔ l 
fs/xfs/xfs.ko.xz
-rw-r--r-- 1 glen users 212K 26. jaan  21:58 fs/xfs/xfs.ko.xz
[~/tmp/kernel-3.18.3-root-glen/lib/modules/3.18.3-1/kernel] ➔

i checked build logs and no match for "Stripping kernel modules" [1]:
http://buildlogs.pld-linux.org//index.php?dist=th&arch=x86_64&ok=1&ns=&cnt=50&off=0&name=kernel&id=87e395d9-22b0-4451-9554-774e0d2b1444
[1] 
https://github.com/pld-linux/rpm-build-macros/blob/auto/th/rpm-build-macros-1.706-1/rpm.macros#L578

apparently kernel compresses themselves and our build automation just 
searches for "*o" only:
https://github.com/pld-linux/rpm-build-macros/blob/auto/th/rpm-build-macros-1.706-1/rpm.macros#L574-L583

-- 
glen