From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Hugh Dickins <hughd@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@gentwo.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Jerome Marchand <jmarchan@redhat.com>,
Yang Shi <yang.shi@linaro.org>,
Sasha Levin <sasha.levin@oracle.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCHv2 27/28] shmem: get_unmapped_area align huge page
Date: Thu, 11 Feb 2016 17:21:55 +0300 [thread overview]
Message-ID: <1455200516-132137-28-git-send-email-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <1455200516-132137-1-git-send-email-kirill.shutemov@linux.intel.com>
From: Hugh Dickins <hughd@google.com>
Provide a shmem_get_unmapped_area method in file_operations, called
at mmap time to decide the mapping address. It could be conditional
on CONFIG_TRANSPARENT_HUGEPAGE, but save #ifdefs in other places by
making it unconditional.
shmem_get_unmapped_area() first calls the usual mm->get_unmapped_area
(which we treat as a black box, highly dependent on architecture and
config and executable layout). Lots of conditions, and in most cases
it just goes with the address that chose; but when our huge stars are
rightly aligned, yet that did not provide a suitable address, go back
to ask for a larger arena, within which to align the mapping suitably.
There have to be some direct calls to shmem_get_unmapped_area(),
not via the file_operations: because of the way shmem_zero_setup()
is called to create a shmem object late in the mmap sequence, when
MAP_SHARED is requested with MAP_ANONYMOUS or /dev/zero. Though
this only matters when /proc/sys/vm/shmem_huge has been set.
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
drivers/char/mem.c | 24 ++++++++++++
include/linux/shmem_fs.h | 2 +
ipc/shm.c | 6 ++-
mm/mmap.c | 16 +++++++-
mm/shmem.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 140 insertions(+), 4 deletions(-)
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 6b1721f978c2..a4c3ce0c9ece 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -22,6 +22,7 @@
#include <linux/device.h>
#include <linux/highmem.h>
#include <linux/backing-dev.h>
+#include <linux/shmem_fs.h>
#include <linux/splice.h>
#include <linux/pfn.h>
#include <linux/export.h>
@@ -661,6 +662,28 @@ static int mmap_zero(struct file *file, struct vm_area_struct *vma)
return 0;
}
+static unsigned long get_unmapped_area_zero(struct file *file,
+ unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+#ifdef CONFIG_MMU
+ if (flags & MAP_SHARED) {
+ /*
+ * mmap_zero() will call shmem_zero_setup() to create a file,
+ * so use shmem's get_unmapped_area in case it can be huge;
+ * and pass NULL for file as in mmap.c's get_unmapped_area(),
+ * so as not to confuse shmem with our handle on "/dev/zero".
+ */
+ return shmem_get_unmapped_area(NULL, addr, len, pgoff, flags);
+ }
+
+ /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */
+ return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
+#else
+ return -ENOSYS;
+#endif
+}
+
static ssize_t write_full(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
@@ -768,6 +791,7 @@ static const struct file_operations zero_fops = {
.read_iter = read_iter_zero,
.write_iter = write_iter_zero,
.mmap = mmap_zero,
+ .get_unmapped_area = get_unmapped_area_zero,
#ifndef CONFIG_MMU
.mmap_capabilities = zero_mmap_capabilities,
#endif
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index c35482b1dd24..85f11d75bfaf 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -53,6 +53,8 @@ extern struct file *shmem_file_setup(const char *name,
extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
unsigned long flags);
extern int shmem_zero_setup(struct vm_area_struct *);
+extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags);
extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
extern bool shmem_mapping(struct address_space *mapping);
extern void shmem_unlock_mapping(struct address_space *mapping);
diff --git a/ipc/shm.c b/ipc/shm.c
index 3174634ca4e5..b797a6e49d78 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -476,13 +476,15 @@ static const struct file_operations shm_file_operations = {
.mmap = shm_mmap,
.fsync = shm_fsync,
.release = shm_release,
-#ifndef CONFIG_MMU
.get_unmapped_area = shm_get_unmapped_area,
-#endif
.llseek = noop_llseek,
.fallocate = shm_fallocate,
};
+/*
+ * shm_file_operations_huge is now identical to shm_file_operations,
+ * but we keep it distinct for the sake of is_file_shm_hugepages().
+ */
static const struct file_operations shm_file_operations_huge = {
.mmap = shm_mmap,
.fsync = shm_fsync,
diff --git a/mm/mmap.c b/mm/mmap.c
index c9d0c412b6dd..6c2044ce9af0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -25,6 +25,7 @@
#include <linux/personality.h>
#include <linux/security.h>
#include <linux/hugetlb.h>
+#include <linux/shmem_fs.h>
#include <linux/profile.h>
#include <linux/export.h>
#include <linux/mount.h>
@@ -2017,8 +2018,19 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
return -ENOMEM;
get_area = current->mm->get_unmapped_area;
- if (file && file->f_op->get_unmapped_area)
- get_area = file->f_op->get_unmapped_area;
+ if (file) {
+ if (file->f_op->get_unmapped_area)
+ get_area = file->f_op->get_unmapped_area;
+ } else if (flags & MAP_SHARED) {
+ /*
+ * mmap_region() will call shmem_zero_setup() to create a file,
+ * so use shmem's get_unmapped_area in case it can be huge.
+ * do_mmap_pgoff() will clear pgoff, so match alignment.
+ */
+ pgoff = 0;
+ get_area = shmem_get_unmapped_area;
+ }
+
addr = get_area(file, addr, len, pgoff, flags);
if (IS_ERR_VALUE(addr))
return addr;
diff --git a/mm/shmem.c b/mm/shmem.c
index 0ba46c92ccc8..6069062d93b0 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1470,6 +1470,94 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
return ret;
}
+unsigned long shmem_get_unmapped_area(struct file *file,
+ unsigned long uaddr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ unsigned long (*get_area)(struct file *,
+ unsigned long, unsigned long, unsigned long, unsigned long);
+ unsigned long addr;
+ unsigned long offset;
+ unsigned long inflated_len;
+ unsigned long inflated_addr;
+ unsigned long inflated_offset;
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ get_area = current->mm->get_unmapped_area;
+ addr = get_area(file, uaddr, len, pgoff, flags);
+
+ if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
+ return addr;
+ if (IS_ERR_VALUE(addr))
+ return addr;
+ if (addr & ~PAGE_MASK)
+ return addr;
+ if (addr > TASK_SIZE - len)
+ return addr;
+
+ if (shmem_huge == SHMEM_HUGE_DENY)
+ return addr;
+ if (len < HPAGE_PMD_SIZE)
+ return addr;
+ if (flags & MAP_FIXED)
+ return addr;
+ /*
+ * Our priority is to support MAP_SHARED mapped hugely;
+ * and support MAP_PRIVATE mapped hugely too, until it is COWed.
+ * But if caller specified an address hint, respect that as before.
+ */
+ if (uaddr)
+ return addr;
+
+ if (shmem_huge != SHMEM_HUGE_FORCE) {
+ struct super_block *sb;
+
+ if (file) {
+ VM_BUG_ON(file->f_op != &shmem_file_operations);
+ sb = file_inode(file)->i_sb;
+ } else {
+ /*
+ * Called directly from mm/mmap.c, or drivers/char/mem.c
+ * for "/dev/zero", to create a shared anonymous object.
+ */
+ if (IS_ERR(shm_mnt))
+ return addr;
+ sb = shm_mnt->mnt_sb;
+ }
+ if (!SHMEM_SB(sb)->huge)
+ return addr;
+ }
+
+ offset = (pgoff << PAGE_SHIFT) & (HPAGE_PMD_SIZE-1);
+ if (offset && offset + len < 2 * HPAGE_PMD_SIZE)
+ return addr;
+ if ((addr & (HPAGE_PMD_SIZE-1)) == offset)
+ return addr;
+
+ inflated_len = len + HPAGE_PMD_SIZE - PAGE_SIZE;
+ if (inflated_len > TASK_SIZE)
+ return addr;
+ if (inflated_len < len)
+ return addr;
+
+ inflated_addr = get_area(NULL, 0, inflated_len, 0, flags);
+ if (IS_ERR_VALUE(inflated_addr))
+ return addr;
+ if (inflated_addr & ~PAGE_MASK)
+ return addr;
+
+ inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1);
+ inflated_addr += offset - inflated_offset;
+ if (inflated_offset > offset)
+ inflated_addr += HPAGE_PMD_SIZE;
+
+ if (inflated_addr > TASK_SIZE - len)
+ return addr;
+ return inflated_addr;
+}
+
#ifdef CONFIG_NUMA
static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol)
{
@@ -3249,6 +3337,7 @@ static const struct address_space_operations shmem_aops = {
static const struct file_operations shmem_file_operations = {
.mmap = shmem_mmap,
+ .get_unmapped_area = shmem_get_unmapped_area,
#ifdef CONFIG_TMPFS
.llseek = shmem_file_llseek,
.read_iter = shmem_file_read_iter,
@@ -3448,6 +3537,13 @@ void shmem_unlock_mapping(struct address_space *mapping)
{
}
+unsigned long shmem_get_unmapped_area(struct file *file,
+ unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
+}
+
void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
{
truncate_inode_pages_range(inode->i_mapping, lstart, lend);
--
2.7.0
next prev parent reply other threads:[~2016-02-11 14:22 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-11 14:21 [PATCHv2 00/28] huge tmpfs implementation using compound pages Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 01/28] thp, dax: do not try to withdraw pgtable from non-anon VMA Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 02/28] rmap: introduce rmap_walk_locked() Kirill A. Shutemov
2016-02-11 18:52 ` Andi Kleen
2016-02-16 9:36 ` Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 03/28] rmap: extend try_to_unmap() to be usable by split_huge_page() Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 04/28] mm: make remove_migration_ptes() beyond mm/migration.c Kirill A. Shutemov
2016-02-12 16:54 ` Dave Hansen
2016-02-16 9:54 ` Kirill A. Shutemov
2016-02-16 15:29 ` Dave Hansen
2016-02-11 14:21 ` [PATCHv2 05/28] thp: rewrite freeze_page()/unfreeze_page() with generic rmap walkers Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 06/28] mm: do not pass mm_struct into handle_mm_fault Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 07/28] mm: introduce fault_env Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 08/28] mm: postpone page table allocation until do_set_pte() Kirill A. Shutemov
2016-02-12 17:44 ` Dave Hansen
2016-02-16 14:26 ` Kirill A. Shutemov
2016-02-16 17:17 ` Dave Hansen
2016-02-23 13:05 ` Kirill A. Shutemov
2016-02-16 17:38 ` Dave Hansen
2016-02-23 22:58 ` Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 09/28] rmap: support file thp Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 10/28] mm: introduce do_set_pmd() Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 11/28] mm, rmap: account file thp pages Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 12/28] thp, vmstats: add counters for huge file pages Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 13/28] thp: support file pages in zap_huge_pmd() Kirill A. Shutemov
2016-02-12 18:33 ` Dave Hansen
2016-02-16 10:00 ` Kirill A. Shutemov
2016-02-16 15:31 ` Dave Hansen
2016-02-18 12:19 ` Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 14/28] thp: handle file pages in split_huge_pmd() Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 15/28] thp: handle file COW faults Kirill A. Shutemov
2016-02-12 18:36 ` Dave Hansen
2016-02-16 10:08 ` Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 16/28] thp: handle file pages in mremap() Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 17/28] thp: skip file huge pmd on copy_huge_pmd() Kirill A. Shutemov
2016-02-12 18:42 ` Dave Hansen
2016-02-16 10:14 ` Kirill A. Shutemov
2016-02-16 15:46 ` Dave Hansen
2016-02-18 12:41 ` Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 18/28] thp: prepare change_huge_pmd() for file thp Kirill A. Shutemov
2016-02-12 18:48 ` Dave Hansen
2016-02-16 10:15 ` Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 19/28] thp: run vma_adjust_trans_huge() outside i_mmap_rwsem Kirill A. Shutemov
2016-02-12 18:50 ` Dave Hansen
2016-02-16 10:16 ` Kirill A. Shutemov
2016-02-16 15:49 ` Dave Hansen
2016-02-11 14:21 ` [PATCHv2 20/28] thp: file pages support for split_huge_page() Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 21/28] vmscan: split file huge pages before paging them out Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 22/28] page-flags: relax policy for PG_mappedtodisk and PG_reclaim Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 23/28] radix-tree: implement radix_tree_maybe_preload_order() Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 24/28] filemap: prepare find and delete operations for huge pages Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 25/28] truncate: handle file thp Kirill A. Shutemov
2016-02-11 14:21 ` [PATCHv2 26/28] shmem: prepare huge=N mount option and /proc/sys/vm/shmem_huge Kirill A. Shutemov
2016-02-11 14:21 ` Kirill A. Shutemov [this message]
2016-02-11 14:21 ` [PATCHv2 28/28] shmem: add huge pages support Kirill A. Shutemov
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