Re: `pci_apply_final_quirks()` taking half a second

[Paul Menzel]

Dear Bjorn,


Am 08.04.2017 um 17:41 schrieb Bjorn Helgaas:
> On Fri, Apr 07, 2017 at 11:07:15PM +0200, Paul Menzel wrote:

> > Measuring where time is spent during boot with `systemd-bootchart`
> > on an Asus A780FullHD, it turns out that half a second is spent in
> > `pci_apply_final_quirks()`.
>
> I agree, that seems like a crazy amount of time.
>
> Can you figure out how to turn on pr_debug() (via the dynamic debug
> mess or whatever) and boot with "initcall_debug"?  That should tell us
> how long each quirk took.

I am sorry for taking so long to reply. I finally added `dyndbg=file 
quirks.c +p` to the command line of Linux 4.13.13. This is on another 
AMD system (Asus F285M Pro).

```
[â]
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:00.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_no_pm_reset+0x0/0x20 returned after 0 usecs for 0000:00:01.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:18.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:18.1
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:18.2
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:18.3
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:18.4
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_mmio_always_on+0x0/0x10 returned after 0 usecs for 0000:00:18.5
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
pci_fixup_video+0x0/0x110 returned after 4 usecs for 0000:00:01.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 197 usecs for 0000:00:10.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 127 usecs for 0000:00:10.1
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 88643 usecs for 
0000:00:12.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 137 usecs for 0000:00:12.2
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
pci_fixup_amd_ehci_pme+0x0/0x30 returned after 1 usecs for 0000:00:12.2
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 85770 usecs for 
0000:00:13.0
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 134 usecs for 0000:00:13.2
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
pci_fixup_amd_ehci_pme+0x0/0x30 returned after 1 usecs for 0000:00:13.2
Dez 26 16:21:46 asus-f2a85-pro kernel: pci fixup 
quirk_usb_early_handoff+0x0/0x6b0 returned after 125 usecs for 
0000:03:00.0[â]
```

So itâs `pci fixup quirk_usb_early_handoff` taking around 85 ms, and 
that twice.

> > Here are the times copied from the SVG:
> >
> >    init_ladder 0.012s
> >    init_menu 0.012s
> >    pm_sysrq_init 0.012s
> >    acpi_init 0.027s
> >    pci_subsys_init 0.008s
> >    hpet_late_init 0.004s
> >    tracer_init_tracefs 0.002s
> >    event_trace_init 0.008s
> >    pnpacpi_init 0.002s
> >    chr_dev_init 0.003s
> >    init_acpi_pm_clocksource 0.004s
> >    pci_apply_final_quirks 0.452s
> >    populate_rootfs 0.400s
> >    pci_iommu_init 0.003s
> >    rsa_init 0.058s
> >    serial8250_init 0.020s
> >    i8042_init 0.003s
> >    load_system_certificate_list 0.002s
> >    ata_init 0.007s
> >    ehci_pci_init 0.030s
> >    ohci_pci_init 0.312s
> >    ahci_pci_driver_init 0.342s
> >    atiixp_pci_driver_init 0.337s
> >    hid_init 0.004s
> >    init_sr 0.031s

[â]
> > Itâd be great, if the times could be reduced, so that the time from
> > GRUB to entering the LUKS passphrase gets smaller.


Kind regards,

Paul