Re: Bad Illegal instruction traps on dual-Xeon (p4) Linux Dell box

From: Zwane Mwaikambo (zwane@linux.realnet.co.sz)
Date: Thu Mar 21 2002 - 02:19:41 EST


On Wed, 20 Mar 2002, James Washer wrote:

>
> The iTLB would be flushed when he did the reload of cr3 ( per your
> suggestion ) UNLESS the G bit was set.
> I suppose theres some small chance, that at the time this instruction was
> first cached and its corresponding iTLB entry was loaded, the G bit may
> have been set.. Seems unlikely. but I'll hack up something to
> unconditionally flush the iTLB.

I find vol3 somewhat confusing in this regard...

P104 - The only ways to deterministically invalidate global page entries
are as follows:
o Clear the PGE flag and then invalidate the TLBs.
o Execute the INVLPG instruction to invalidate individual page-directory
  or page-table entries in the TLBs.
o Write to control register CR3 to invalidate all TLB entries.

Then on page 381.

The following operations invalidate all TLB entries except global entries.
(A global entry is one for which the G (global) flag is set in its
corresponding page-directory or page-table entry. The global flag was
introduced into the IA-32 architecture in the P6 family processors, see
Section 10.5., Cache Control .)

o Writing to control register CR3.
o A task switch that changes control register CR3.

I would reckon reference 1 (p104) is incorrect, can someone shed some
light?

Thanks,
        Zwane

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Mar 23 2002 - 22:00:24 EST