Add back check_pgt_cache call.

Add nop definition for x86.

include/asm-i386/pgalloc.h

@@ -223,4 +223,6 @@ static inline void flush_tlb_pgtables(struct mm_struct *mm,
 	/* i386 does not keep any page table caches in TLB */
 }
 
+#define check_pgt_cache()	do { } while (0)
+
 #endif /* _I386_PGALLOC_H */

mm/memory.c

@@ -140,6 +140,9 @@ void clear_page_tables(struct mm_struct *mm, unsigned long first, int nr)
 		page_dir++;
 	} while (--nr);
 	spin_unlock(&mm->page_table_lock);
+
+	/* keep the page table cache within bounds */
+	check_pgt_cache();
 }
 
 pte_t * pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address)