I added further instrumentation and got this profile of where the
remaining time goes
1000x drive_new 18.347secs
-> 1000x blockdev_init 18.328secs
-> 1000x monitor_add_blk 4.515secs
-> 1000x blk_by_name 1.545secs
-> 1000x bdrv_find_node 2.968secs
-> 1000x blk_new_open 13.786secs
I instrumented drive_new to time how long 1000 creations took with
current code:
1000 drive_new() in 0 secs
1000 drive_new() in 2 secs
1000 drive_new() in 18 secs
1000 drive_new() in 61 secs
As a quick hack you can just disable the drive_get() calls when if=none.
They're mostly just used to fill
The first place where it ages an insane amount of time is simply
processing -drive options. The stack trace I see is this
(gdb) bt
#0 0x5583b596719a in drive_get (type=type@entry=IF_NONE, bus=bus@entry=0,
unit=unit@entry=2313) at blockdev.c:223
#1 0x5583b59679bd in drive_new (all_opts=0
