[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1457737157-38573-6-git-send-email-kirill.shutemov@linux.intel.com>
Date: Sat, 12 Mar 2016 01:58:57 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Hugh Dickins <hughd@...gle.com>,
Andrea Arcangeli <aarcange@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>
Cc: Dave Hansen <dave.hansen@...el.com>,
Vlastimil Babka <vbabka@...e.cz>,
Christoph Lameter <cl@...two.org>,
Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
Jerome Marchand <jmarchan@...hat.com>,
Yang Shi <yang.shi@...aro.org>,
Sasha Levin <sasha.levin@...cle.com>,
linux-kernel@...r.kernel.org, linux-mm@...ck.org,
linux-fsdevel@...r.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCHv4 05/25] mm: introduce do_set_pmd()
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 <kirill.shutemov@...ux.intel.com>
---
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
Powered by blists - more mailing lists