Re: regression: 2f569af (CONFIG_HIGHPTE vs. sub-page page tables.)

[Martin Schwidefsky <schwidefsky@de.ibm.com>]

On Mon, 2008-02-25 at 14:26 +0100, Uwe Kleine-König wrote:
> I see the following:
> 
> 	/ # for i in 1 2 3; do grep PageTables /proc/meminfo; done
> 	PageTables:          4 kB
> 	PageTables:   4294967292 kB
> 	PageTables:   4294967284 kB
> 
> and I bisected it down to 2f569af (CONFIG_HIGHPTE vs. sub-page page
> tables.)  This still happens in 2.6.25-rc3.
> 
> I have not investigated further, so I cannot tell if it's only the
> output in meminfo that is broken.
> 
> This is on ARCH=arm, on a Digi cc9p9360 with ns9xxx_defconfig.

Hmm, not good. The number obviously went negative. There is an imbalance
in the number of pgtable_page_ctor vs. pgtable_page_dtor. Could you try
this patch and watch for warnings?

-- 
blue skies,
  Martin.

"Reality continues to ruin my life." - Calvin.

---
diff --git a/include/asm-arm/pgalloc.h b/include/asm-arm/pgalloc.h
index 163b030..eeb973a 100644
--- a/include/asm-arm/pgalloc.h
+++ b/include/asm-arm/pgalloc.h
@@ -94,6 +94,7 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 
 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
 {
+	WARN_ON(!pte);
 	pgtable_page_dtor(pte);
 	__free_page(pte);
 }