On 13/01/2021 15.41, Takashi Iwai wrote:
On Wed, 13 Jan 2021 14:57:06 +0100, Marcus Meissner wrote:
On Wed, Jan 13, 2021 at 01:53:36PM +0000, Michael Schroeder wrote:
On Wed, Jan 13, 2021 at 02:43:00PM +0100, Stephan Kulow wrote:
Well, you can still serialze the scriplet part and parallelize the payload uncompression and file installation
Maybe, but somewhat should first take a look where all the time is spent in the rpm installation code. Maybe uncompression is just 10% and file system operation is 70%. Or the other way round. Or maybe it's the fsync() on the database?
It is the dracut initrd regeneration for me actually, even on SSD it takes *minutes* :).
That's a long-standing pain, yeah. Did anyone profile the dracut operation to point out what takes so long? I know xz takes quite some time, but it's not dominant, I guess.
On 15.2 I prefixed some commands with /usr/bin/time -p to get for cpio: real 4.06 user 0.05 sys 0.13 for xz (the line with | $compress) real 4.18 user 4.14 sys 0.02 total run time for 2 kernels is real 0m20.917s user 0m17.552s sys 0m3.835s so the compression alone takes 40% of the total time. Using date '+%s.%N' I found that another 28% (2.95s per kernel) is spent on the section "Including module"