Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933144AbcCKW7z (ORCPT ); Fri, 11 Mar 2016 17:59:55 -0500 Received: from mga02.intel.com ([134.134.136.20]:34808 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753087AbcCKW7a (ORCPT ); Fri, 11 Mar 2016 17:59:30 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,321,1455004800"; d="scan'208";a="908395054" From: "Kirill A. Shutemov" To: Hugh Dickins , Andrea Arcangeli , Andrew Morton Cc: Dave Hansen , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Jerome Marchand , Yang Shi , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv4 05/25] mm: introduce do_set_pmd() Date: Sat, 12 Mar 2016 01:58:57 +0300 Message-Id: <1457737157-38573-6-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457737157-38573-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1457737157-38573-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4180 Lines: 155 With postponed page table allocation we have chance to setup huge pages. do_set_pte() calls do_set_pmd() if following criteria met: - page is compound; - pmd entry in pmd_none(); - vma has suitable size and alignment; Signed-off-by: Kirill A. Shutemov --- include/linux/huge_mm.h | 2 ++ mm/huge_memory.c | 8 ------ mm/memory.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++- mm/migrate.c | 3 +-- 4 files changed, 74 insertions(+), 11 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 24918897f073..193fccdc275d 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -147,6 +147,8 @@ static inline bool is_huge_zero_pmd(pmd_t pmd) struct page *get_huge_zero_page(void); +#define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot)) + #else /* CONFIG_TRANSPARENT_HUGEPAGE */ #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1b111d5c0312..2e9e6f4afe40 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -780,14 +780,6 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) return pmd; } -static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot) -{ - pmd_t entry; - entry = mk_pmd(page, prot); - entry = pmd_mkhuge(entry); - return entry; -} - static inline struct list_head *page_deferred_list(struct page *page) { /* diff --git a/mm/memory.c b/mm/memory.c index a6c1c4955560..0109db96fdff 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2837,6 +2837,66 @@ map_pte: return 0; } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + +#define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1) +static inline bool transhuge_vma_suitable(struct vm_area_struct *vma, + unsigned long haddr) +{ + if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) != + (vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK)) + return false; + if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) + return false; + return true; +} + +static int do_set_pmd(struct fault_env *fe, struct page *page) +{ + struct vm_area_struct *vma = fe->vma; + bool write = fe->flags & FAULT_FLAG_WRITE; + unsigned long haddr = fe->address & HPAGE_PMD_MASK; + pmd_t entry; + int i, ret; + + if (!transhuge_vma_suitable(vma, haddr)) + return VM_FAULT_FALLBACK; + + ret = VM_FAULT_FALLBACK; + page = compound_head(page); + + fe->ptl = pmd_lock(vma->vm_mm, fe->pmd); + if (unlikely(!pmd_none(*fe->pmd))) + goto out; + + for (i = 0; i < HPAGE_PMD_NR; i++) + flush_icache_page(vma, page + i); + + entry = mk_huge_pmd(page, vma->vm_page_prot); + if (write) + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); + + add_mm_counter(vma->vm_mm, MM_FILEPAGES, HPAGE_PMD_NR); + page_add_file_rmap(page, true); + + set_pmd_at(vma->vm_mm, haddr, fe->pmd, entry); + + update_mmu_cache_pmd(vma, haddr, fe->pmd); + + /* fault is handled */ + ret = 0; +out: + spin_unlock(fe->ptl); + return ret; +} +#else +static int do_set_pmd(struct fault_env *fe, struct page *page) +{ + BUILD_BUG(); + return 0; +} +#endif + /** * alloc_set_pte - setup new PTE entry for given page and add reverse page * mapping. If needed, the fucntion allocates page table or use pre-allocated. @@ -2856,9 +2916,19 @@ int alloc_set_pte(struct fault_env *fe, struct mem_cgroup *memcg, struct vm_area_struct *vma = fe->vma; bool write = fe->flags & FAULT_FLAG_WRITE; pte_t entry; + int ret; + + if (pmd_none(*fe->pmd) && PageTransCompound(page)) { + /* THP on COW? */ + VM_BUG_ON_PAGE(memcg, page); + + ret = do_set_pmd(fe, page); + if (ret != VM_FAULT_FALLBACK) + return ret; + } if (!fe->pte) { - int ret = pte_alloc_one_map(fe); + ret = pte_alloc_one_map(fe); if (ret) return ret; } diff --git a/mm/migrate.c b/mm/migrate.c index d20276fffce7..5c9cd90334ea 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1820,8 +1820,7 @@ fail_putback: } orig_entry = *pmd; - entry = mk_pmd(new_page, vma->vm_page_prot); - entry = pmd_mkhuge(entry); + entry = mk_huge_pmd(new_page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); /* -- 2.7.0