This replaces the parallel gzip with the boring gzip from Go's standard
lib. The main motivations for doing this are:
1) Reduce runtime memory requirements
2) shed some external dependencies
There's obviously a trade-off with compression speed/time (as seen
below), but I feel like it's a worthwhile trade-off.
Note that there's likely very little impact to boot performance wrt
extracting these archives, the compression levels are similar.
Measured on a Shift 6mq, which is a very fast phone...
** compress/gzip:
User time (seconds): 1.81
System time (seconds): 0.38
Percent of CPU this job got: 104%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:02.09
Maximum resident set size (kbytes): 62024
-rw-r--r-- 1 clayton clayton 6.1M Sep 20 17:20 initramfs
-rw-r--r-- 1 clayton clayton 2.5M Sep 20 17:20 initramfs-extra
** pgzip:
User time (seconds): 1.19
System time (seconds): 0.48
Percent of CPU this job got: 159%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.05
Maximum resident set size (kbytes): 109952
-rw-r--r-- 1 clayton clayton 6.8M Sep 20 17:20 initramfs
-rw-r--r-- 1 clayton clayton 2.8M Sep 20 17:20 initramfs-extra
inspired by: https://gitlab.com/postmarketOS/pmaports/-/issues/1704
Checking for the app is unnecessary, since the cmd.Run later will fail
if it doesn't exist. This allows dropping the dependency on misc.Exists.
There's also no reason to print that the command failed, just return the
error.
This is kinda janky, passing both a list of modules and a directory path
is just because we support modules in deviceinfo and in directory file
lists... Maybe one day we can move away from having modules in the
deviceinfo...
