Messages in this thread | | | Date | Wed, 18 Jun 2008 22:11:08 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH] x86: update mptable v7 |
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On Wed, Jun 18, 2008 at 9:32 PM, Eric W. Biederman <ebiederm@xmission.com> wrote: > "Yinghai Lu" <yhlu.kernel@gmail.com> writes: > >> On Wed, Jun 18, 2008 at 5:33 PM, Len Brown <lenb@kernel.org> wrote: >>> >>> >>> On Wed, 18 Jun 2008, Yinghai Lu wrote: >>> >>>> On Wed, Jun 18, 2008 at 3:18 PM, Len Brown <lenb@kernel.org> wrote: >>>> > >>>> > >>>> > On Sun, 1 Jun 2008, Yinghai Lu wrote: >>>> > >>>> >> >>>> >> make mptable to be consistent to acpi routing, so we could >>>> >> 1. kexec kernel with acpi=off >>>> >> 2. workaround BIOS that acpi routing is working, but mptable is not right. >>>> >> so can use kernel/kexec to start other os that doesn't have good acpi >> support >>>> > >>>> > Is this an effort to boot an ACPI-mode kernel, >>>> > and then kexec a non-ACPI kernel? >>>> >>>> Yes, >>> >>> Why is this feature needed? >>> There are a number of ways that the resulting kernel may fail, >>> all platform specific. >> >> other os still doesn't have update acpi irq routing support. but has >> broken mptable. > > Which is at least in part a reason to go back to the BIOS manufacturer > and get them to fix their table. > > I can see a warning coming from the kernel if these two tables are inconsistent > though. > >>>> > Doing so could confuse the heck out of the platform firmware, >>>> > which will think that an ACPI-mode kernel is still running. >>>> > >>>> > Note that it is a historic artifact, now considered a bug, >>>> > that ACPI uses the MPS code. We should be divorcing these >>>> > two bodies of code rather than mixing them further. >>>> >>>> how about adding config option to not compile mptable related info? >>> >>> That's the idea. >>> CONFIG_MPS=n CONFIG_ACPI=y should build and run on >>> every PC built in this century. >>> >>> This was prototyped a long while back, but the >>> tree has churned so much since then the old >>> prototype is worthless. >> >> will look at it tonight. >> >> when EFI is popular, there is no reason to compile mps related stuff >> in kernel again. esp for 64 bit. > > ? EFI has nothing to do with this. ACPI is popular today and EFI preserves > EFI. > >> BTW, it is funny that Suse still has fallsafe boot entry with acpi=off. > > Silly question. Given that even writing to this table is platform specific. > Any chance we can do this any a userspace utility writing through /dev/mem > for the systems that need it? We can even bundle the utility in the kexec-tools > package to make it easier to distribute.
interesting, never thought that.
need to call pci_acpi_enable_irq==>mp_config_acpi_gsi in kernel to save mp_irqs...
also we could use old kernel kexec second kernel (with this patch and acpi, and uptable) and then use second kernel to kexec last kernel...
YH
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