>On Thu, Oct 18, 2012 at 01:50:10PM -0700, Yinghai Lu wrote:
I am pretty sure I gave you some ideas of how to fix up the commit description in earlier reviews, but it looks like you missed them. Let me write them here once more. > We are going to use buffer in BRK to pre-map page table buffer. What buffer? Is buffer the same thing as page table? > > Page table buffer could be only page aligned, but range around it are .. ranges > ram too, we could use bigger page to map it to avoid small pages. > > We will adjust page_size_mask in next patch to use big page size for Instead of saying "next patch" - include the title of the patch so that one can search for it. > small ram range. > > Before that, this patch will make start address to be aligned down s/will make/made/ > according to bigger page size, otherwise entry in page page will > not have correct value. I would structure this git commit description to first introduce the problem. Say at the start of the patch: "Before this patch, the start address was aligned down according to bigger a page size (1GB, 2MB). This is a problem b/c an entry in the page table will not have correct value. " Here can you explain why it does not have the correct value? > > Signed-off-by: Yinghai Lu <[email protected]> > --- > arch/x86/mm/init_32.c | 1 + > arch/x86/mm/init_64.c | 5 +++-- > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c > index 11a5800..27f7fc6 100644 > --- a/arch/x86/mm/init_32.c > +++ b/arch/x86/mm/init_32.c > @@ -310,6 +310,7 @@ repeat: > __pgprot(PTE_IDENT_ATTR | > _PAGE_PSE); > > + pfn &= PMD_MASK >> PAGE_SHIFT; > addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + > PAGE_OFFSET + PAGE_SIZE-1; > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index ab558eb..f40f383 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -461,7 +461,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, > unsigned long end, > pages++; > spin_lock(&init_mm.page_table_lock); > set_pte((pte_t *)pmd, > - pfn_pte(address >> PAGE_SHIFT, > + pfn_pte((address & PMD_MASK) >> PAGE_SHIFT, > __pgprot(pgprot_val(prot) | > _PAGE_PSE))); > spin_unlock(&init_mm.page_table_lock); > last_map_addr = next; > @@ -536,7 +536,8 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, > unsigned long end, > pages++; > spin_lock(&init_mm.page_table_lock); > set_pte((pte_t *)pud, > - pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); > + pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT, > + PAGE_KERNEL_LARGE)); > spin_unlock(&init_mm.page_table_lock); > last_map_addr = next; > continue; > -- > 1.7.7 > > -- > 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/ > -- 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/
