Thinning out GENERIC

[John Baldwin]

On Friday, February 17, 2017 12:54:29 PM Sean Bruno wrote:
> 
> On 02/17/17 12:49, John Baldwin wrote:
> > On Friday, February 17, 2017 11:43:45 AM Sean Bruno wrote:
> >>
> >> On 02/13/17 11:33, John Baldwin wrote:
> >>> On Monday, February 13, 2017 10:51:36 AM Warner Losh wrote:
> >>>> [[ It isn't just GENERIC, it's in every single kernel ]]
> >>>>
> >>>> On Sun, Feb 12, 2017 at 7:59 AM, Sean Bruno <sbruno at freebsd.org> wrote:
> >>>>> Index: sys/conf/files
> >>>>> ===================================================================
> >>>>> --- sys/conf/files      (revision 313683)
> >>>>> +++ sys/conf/files      (working copy)
> >>>>> @@ -2419,7 +2419,7 @@
> >>>>>  dev/pci/pci_user.c             optional pci
> >>>>>  dev/pci/pcib_if.m              standard
> >>>>>  dev/pci/pcib_support.c         standard
> >>>>> -dev/pci/vga_pci.c              optional pci
> >>>>> +#dev/pci/vga_pci.c             optional pci
> >>>>>  dev/pcn/if_pcn.c               optional pcn pci
> >>>>>  dev/pdq/if_fea.c               optional fea eisa
> >>>>>  dev/pdq/if_fpa.c               optional fpa pci
> >>>>>
> >>>>> I'm playing around with small x86 builds and wanted to come up with a
> >>>>> knob that disables the vga_pci driver.  Obviously I still want pci(4) to
> >>>>> be enabled, but I definitely do not need the vga interfaces for
> >>>>> anything.  Any suggestions?
> >>>>
> >>>> You could make it dependent on vt or sc as well as pci, no?
> >>>
> >>> This is a fairly small driver:
> >>>
> >>>      6139      340         8      6487     0x1957   /usr/obj/usr/src/sys/GENERIC
> >>> /vga_pci.o
> >>>
> >>> (From an 11.0-stable build)
> >>>
> >>> device ppc and friends is a lot more for example:
> >>>
> >>>   text   data   bss    dec      hex   filename
> >>>   6238      0     0   6238   0x185e   /usr/obj/usr/src/sys/GENERIC/ppb_1284.o
> >>>   1675     28     0   1703    0x6a7   /usr/obj/usr/src/sys/GENERIC/ppb_base.o
> >>>   2042      0     0   2042    0x7fa   /usr/obj/usr/src/sys/GENERIC/ppb_msq.o
> >>>   6025    296     8   6329   0x18b9   /usr/obj/usr/src/sys/GENERIC/ppbconf.o
> >>>      0    168     0    168     0xa8   /usr/obj/usr/src/sys/GENERIC/ppbus_if.o
> >>>   9099     36     0   9135   0x23af   /usr/obj/usr/src/sys/GENERIC/ppc.o
> >>>    495    256     0    751    0x2ef   /usr/obj/usr/src/sys/GENERIC/ppc_acpi.o
> >>>   1671    256     0   1927    0x787   /usr/obj/usr/src/sys/GENERIC/ppc_isa.o
> >>>   1124    208     0   1332    0x534   /usr/obj/usr/src/sys/GENERIC/ppc_pci.o
> >>>    451    208     0    659    0x293   /usr/obj/usr/src/sys/GENERIC/ppc_puc.o
> >>>   2751    428     8   3187    0xc73   /usr/obj/usr/src/sys/GENERIC/ppi.o
> >>>
> >>> It is needed for drm.
> >>>
> >>
> >> Ok, so ... make it dependant on drm, vt, sc and pci?
> > 
> > You can kldload drm at runtime, so a static dependency isn't sufficient.
> > It's not clear why removing this from GENERIC is that important.  ppc is on far
> > fewer machines than vga_pci and takes up 10x more space.
> > 
> 
> I don't want to remove it from GENERIC.  I want to add the capability to
> remove it.  Sorry if that wasn't clear from my subject line, because it
> doesn't look clear now that I re-read it.

Why not make this conditional on 'vga'?  GENERIC already contains 'device vga'
that the VGA-specific bits of 'vt', etc. are dependent on.

-- 
John Baldwin