Re: [Xen-devel] 2.6.27 - SMP enabled, but only 1 CPU

From: Jeremy Fitzhardinge
Date: Thu Nov 06 2008 - 16:48:36 EST


Ingo Molnar wrote:
where exactly is that use? My grep didnt show any users of pud_page(). pud_page() was changed in an incompatible way, all users of it must be updated.

pgd_page() uses it in pgtable-nopud.h, so any users of pgd_page() also need to be looked at. It so happens the only user is arch/x86/xen/mmu.c, which expects it to return the vaddr. Fixed below.

J

Subject: xen: fix use of pgd_page now that it really does return a page

On 32-bit PAE, pud_page, for no good reason, didn't really return a
struct page *. Since Jan Beulich's fix "i386/PAE: fix pud_page()",
pud_page does return a struct page *.

Because PAE has 3 pagetable levels, the pud level is folded into the
pgd level, so pgd_page() is the same as pud_page(), and now returns
a struct page *. Update the xen/mmu.c code which uses pgd_page()
accordingly.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/xen/mmu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

===================================================================
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -877,7 +877,7 @@
#else /* CONFIG_X86_32 */
#ifdef CONFIG_X86_PAE
/* Need to make sure unshared kernel PMD is pinnable */
- xen_pin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+ xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
PT_PMD);
#endif
xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
@@ -994,7 +994,7 @@

#ifdef CONFIG_X86_PAE
/* Need to make sure unshared kernel PMD is unpinned */
- xen_unpin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+ xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
PT_PMD);
#endif



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