Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932763AbVLIAQj (ORCPT ); Thu, 8 Dec 2005 19:16:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932765AbVLIAQj (ORCPT ); Thu, 8 Dec 2005 19:16:39 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:7138 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S932763AbVLIAQi (ORCPT ); Thu, 8 Dec 2005 19:16:38 -0500 Subject: Re: 2.6.15-rc4 panic in __nr_to_section() with CONFIG_SPARSEMEM From: Dave Hansen To: David Gibson Cc: Badari Pulavarty , Andy Whitcroft , lkml , "ADAM G. LITKE [imap]" In-Reply-To: <20051208234841.GA30254@localhost.localdomain> References: <1133995060.21841.56.camel@localhost.localdomain> <43976AA4.2060606@uk.ibm.com> <1133997772.21841.62.camel@localhost.localdomain> <1134002888.30387.82.camel@localhost> <1134058055.21841.70.camel@localhost.localdomain> <1134069335.6159.21.camel@localhost> <20051208234841.GA30254@localhost.localdomain> Content-Type: text/plain Date: Thu, 08 Dec 2005 16:16:29 -0800 Message-Id: <1134087389.18179.2.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4220 Lines: 132 On Fri, 2005-12-09 at 10:48 +1100, David Gibson wrote: > On Thu, Dec 08, 2005 at 11:15:35AM -0800, Dave Hansen wrote: > > On Thu, 2005-12-08 at 08:07 -0800, Badari Pulavarty wrote: > > > No. It doesn't help. It looks like ppc pmd_huge() always returns 0. > > > Don't know why ? :( > > > > The ppc64 hugetlb pages don't line up on PMD boundaries like they do on > > i386. The entries are stored in regular old PTEs. > > > > I really don't like coding the two different hugetlb cases, but I can't > > think of a better way to do it. Anyone care to test on ppc64? > > > - mss->resident += PAGE_SIZE; > > + page_size = PAGE_SIZE; > > + if (is_hugepage_only_range(vma->vm_mm, addr, end - addr)) > > + page_size = HPAGE_SIZE; > > This is an incorrect usage of is_hugepage_only_range(). Although it > will get the right answer by accident here, that function should > *only* be used for testing whether a range is suitable for normal > pages, never for determining if hugepages are actually in use here. > You have the VMA here, so test its flag instead here. Sounds good to me. The flag should be faster to test as well. Updated patch attached. Shall I cook another one up to comment is_hugepage_only_range() so poor suckers like me don't make the mistake again? -- Dave proc-dups-dave/fs/proc/task_mmu.c | 53 +++++++++++++++++++++++++++----------- 2 files changed, 39 insertions(+), 14 deletions(-) diff -puN fs/proc/task_mmu.c~task_mmu_fix fs/proc/task_mmu.c --- proc-dups/fs/proc/task_mmu.c~task_mmu_fix 2005-12-07 16:34:38.000000000 -0800 +++ proc-dups-dave/fs/proc/task_mmu.c 2005-12-08 16:13:55.000000000 -0800 @@ -198,6 +198,24 @@ static int show_map(struct seq_file *m, return show_map_internal(m, v, NULL); } +static void smaps_account_for_page(pte_t ptent, struct page *page, + unsigned long page_size, + struct mem_size_stats *mss) +{ + mss->resident += page_size; + if (page_count(page) >= 2) { + if (pte_dirty(ptent)) + mss->shared_dirty += page_size; + else + mss->shared_clean += page_size; + } else { + if (pte_dirty(ptent)) + mss->private_dirty += page_size; + else + mss->private_clean += page_size; + } +} + static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, struct mem_size_stats *mss) @@ -205,32 +223,38 @@ static void smaps_pte_range(struct vm_ar pte_t *pte, ptent; spinlock_t *ptl; unsigned long pfn; + unsigned long page_size; struct page *page; + if (pmd_huge(*pmd)) { + struct page *page; + + page = follow_huge_pmd(vma->vm_mm, addr, pmd, 0); + if (!page) + return; + + ptent = *(pte_t *)pmd; + smaps_account_for_page(ptent, page, HPAGE_SIZE, mss); + return; + } pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); do { ptent = *pte; if (!pte_present(ptent)) continue; - mss->resident += PAGE_SIZE; + page_size = PAGE_SIZE; + if (is_vm_hugetlb_page(vma)) + page_size = HPAGE_SIZE; + + mss->resident += page_size; pfn = pte_pfn(ptent); if (!pfn_valid(pfn)) continue; page = pfn_to_page(pfn); - if (page_count(page) >= 2) { - if (pte_dirty(ptent)) - mss->shared_dirty += PAGE_SIZE; - else - mss->shared_clean += PAGE_SIZE; - } else { - if (pte_dirty(ptent)) - mss->private_dirty += PAGE_SIZE; - else - mss->private_clean += PAGE_SIZE; - } - } while (pte++, addr += PAGE_SIZE, addr != end); + smaps_account_for_page(ptent, page, page_size, mss); + } while (pte++, addr += page_size, addr != end); pte_unmap_unlock(pte - 1, ptl); cond_resched(); } @@ -245,7 +269,8 @@ static inline void smaps_pmd_range(struc pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); - if (pmd_none_or_clear_bad(pmd)) + + if (!pmd_huge(*pmd) && pmd_none_or_clear_bad(pmd)) continue; smaps_pte_range(vma, pmd, addr, next, mss); } while (pmd++, addr = next, addr != end); diff -puN include/linux/hugetlb.h~task_mmu_fix include/linux/hugetlb.h _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/