Re: [PATCH/RFC] Re: Kernel selection on i386 for Xen compatibility
On Wed, 2008-05-07 at 15:35 +0200, Frans Pop wrote:
> On Saturday 03 May 2008, Ian Campbell wrote:
> > v2 patch is below.
>
> This looks reasonable. Essential characteristic of the patch is that bigmem
> is only proposed if:
> - the system has pae support
> - the installer itself is also running a bigmem kernel
That's correct. I had considered the option of also installing -bigmem
if "pae && RAM>=4G" but decided not to.
> One question: is pae something used by both Intel and AMD?
I'm pretty sure it is the same on AMD and Intel.
$ grep -E vendor_id\|flags /proc/cpuinfo | head -n 2
vendor_id : GenuineIntel
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm
constant_tsc pni monitor ds_cpl vmx tm2 cx16 xtpr lahf_lm
$ grep -E vendor_id\|flags /proc/cpuinfo | head -n 2
vendor_id : AuthenticAMD
flags : fpu de tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush
mmx fxsr sse sse2 syscall nx mmxext fxsr_opt lm 3dnowext 3dnow up
lahf_lm
> I seem to recall that one had something different. In that case, should this
> be extended to also cover whatever the other manufacturer has?
>
> Please submit the final patch as a wishlist BR against base-installer with a
> link to this discussion in the mailing list archives.
Will do. Thanks,
Ian.
>
> > Index: kernel/i386.sh
> > ===================================================================
> > --- kernel/i386.sh (revision 53021)
> > +++ kernel/i386.sh (working copy)
> > @@ -2,16 +2,24 @@
> > VENDOR=`grep '^vendor_id' "$CPUINFO" | head -n1 | cut -d: -f2`
> > FAMILY=`grep '^cpu family' "$CPUINFO" | head -n1 | cut -d: -f2`
> > MODEL=`grep '^model[[:space:]]*:' "$CPUINFO" | head -n1 | cut -d: -f2`
> > +
> > + if grep '^flags' "$CPUINFO" | grep -q pae ; then
> > + case "$KERNEL_FLAVOUR" in
> > + 686-bigmem*) BIGMEM="-bigmem" ;;
> > + *) ;;
> > + esac
> > + fi
>
> This could do with a comment before the new code:
> # Only offer bigmem is the system supports pae and the installer
> # itself is also using a bigmem kernel
>
> Cheers,
> FJP
--
Ian Campbell
Current Noise: Rollins Band - Almost Real
I know not how I came into this, shall I call it a dying life or a
living death?
-- St. Augustine
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