Chris Wright wrote:
* Zachary Amsden ([EMAIL PROTECTED]) wrote:--- linux-2.6.13.orig/arch/i386/mm/init.c 2005-08-24 09:31:05.000000000 -0700 +++ linux-2.6.13/arch/i386/mm/init.c 2005-08-24 09:31:31.000000000 -0700 @@ -79,6 +79,7 @@ static pte_t * __init one_page_table_ini { if (pmd_none(*pmd)) { pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + SetPagePTE(virt_to_page(page_table));Xen has this on one_md_table_init() as well for pmd.
I'll add that in another patch. It's easy to miss some of the init time call sites (we don't actually depend on them for correctness).
spin_lock_irqsave(&pgd_lock, flags); pgd_list_del(pgd); spin_unlock_irqrestore(&pgd_lock, flags); @@ -244,13 +246,16 @@ pgd_t *pgd_alloc(struct mm_struct *mm) pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL); if (!pmd) goto out_oom; + SetPagePDE(virt_to_page(pmd)); set_pgd(&pgd[i], __pgd(1 + __pa(pmd))); } return pgd; out_oom: - for (i--; i >= 0; i--) + for (i--; i >= 0; i--) { + ClearPagePDE(pfn_to_page(pgd_val(pgd[i]) >> PAGE_SHIFT));Is that the right pfn? That -1 throws me off.kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); + } kmem_cache_free(pgd_cache, pgd); return NULL; } @@ -261,8 +266,10 @@ void pgd_free(pgd_t *pgd) /* in the PAE case user pgd entries are overwritten before usage */ if (PTRS_PER_PMD > 1) - for (i = 0; i < USER_PTRS_PER_PGD; ++i) - kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); + for (i = 0; i < USER_PTRS_PER_PGD; ++i) { + ClearPagePDE(pfn_to_page(pgd_val(pgd[i]) >> PAGE_SHIFT)); + kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i]) & PAGE_MASK));Why the switch of kmem_cache_free call?
Because pgd_val(pgd[i])-1 is confusing. Using (pgd_val(pgd[i]) - _PAGE_PRESENT) would be better, but the +/- 1s all over the place here could use some general cleanup as well. I smell a cleanup fit coming on. Using (pgd_val(pgd[i]) & PAGE_MASK) is a less error prone way to get the physical frame bits, since it is not wrong if you turn on PCD or PWD.
Zach - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
