[arch-general] Multi-threaded mkinitpcio

[Lone_Wolf]

On 06-04-2020 12:43, Ralph Corderoy wrote:
> Hi Lone Wolf,
>
>>>       $ perf stat -e instructions gzip <initramfs-linux-lts-fallback >/dev/null
>>>       $ perf stat -e instructions lzop <initramfs-linux-lts-fallback >/dev/null
>> Those outputs appear to be from unpacking initramfs.
>> I do think OP and Giancarlo were talking about creating an initramfs .
> Oh, sorry for the noise if I'm wrong, but
> /boot/initramfs-linux-lts-fallback.img is gzip-compressed here.
> I uncompressed it to give the initramfs-linux-lts-fallback used above.
> I thought the compression of it was the step OP and Giancarlo were
> discussing, as you say.
>

Guess I misinterpretated the command, ralph .

Below are some data from my own system (threadripper 1920x , NvME2 ssd) .

lzop is about twice as fast as gzip , while xz is very slow.

Lone_Wolf


$ perf stat -e instructions mkinitcpio --generate testing --compress 
gzip > /dev/null

  Performance counter stats for 'mkinitcpio --generate testing 
--compress gzip':

     16,585,047,999 instructions:u

        4.706074377 seconds time elapsed

        4.000137000 seconds user
        1.187220000 seconds sys


$ perf stat -e instructions mkinitcpio --generate testing --compress xz 
 > /dev/null

  Performance counter stats for 'mkinitcpio --generate testing 
--compress xz':

     84,360,010,752 instructions:u

       17.415348248 seconds time elapsed

       16.756740000 seconds user
        1.500338000 seconds sys


$ perf stat -e instructions mkinitcpio --generate testing --compress 
lzop > /dev/null

  Performance counter stats for 'mkinitcpio --generate testing 
--compress lzop':

      5,316,618,410 instructions:u

        2.426944720 seconds time elapsed

        1.695263000 seconds user
        1.027651000 seconds sys


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