The patch titled
hugetlb: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions
has been added to the -mm tree. Its filename is
hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions.patch
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out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: hugetlb: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions
From: Eric B Munson <ebmunson@xxxxxxxxxx>
Add a flag for mmap that will be used to request a huge page region that
will look like anonymous memory to userspace. This is accomplished by
using a file on the internal vfsmount. MAP_HUGETLB is a modifier of
MAP_ANONYMOUS and so must be specified with it. The region will behave
the same as a MAP_ANONYMOUS region using small pages.
Signed-off-by: Eric B Munson <ebmunson@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Adam Litke <agl@xxxxxxxxxx>
Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-generic/mman-common.h | 1 +
include/linux/hugetlb.h | 7 +++++++
mm/mmap.c | 19 +++++++++++++++++++
3 files changed, 27 insertions(+)
diff -puN include/asm-generic/mman-common.h~hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions include/asm-generic/mman-common.h
--- a/include/asm-generic/mman-common.h~hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions
+++ a/include/asm-generic/mman-common.h
@@ -19,6 +19,7 @@
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
+#define MAP_HUGETLB 0x40 /* create a huge page mapping */
#define MS_ASYNC 1 /* sync memory asynchronously */
#define MS_INVALIDATE 2 /* invalidate the caches */
diff -puN include/linux/hugetlb.h~hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions include/linux/hugetlb.h
--- a/include/linux/hugetlb.h~hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions
+++ a/include/linux/hugetlb.h
@@ -110,12 +110,19 @@ static inline void hugetlb_report_meminf
#endif /* !CONFIG_HUGETLB_PAGE */
+#define HUGETLB_ANON_FILE "anon_hugepage"
+
enum {
/*
* The file will be used as an shm file so shmfs accounting rules
* apply
*/
HUGETLB_SHMFS_INODE = 1,
+ /*
+ * The file is being created on the internal vfs mount and shmfs
+ * accounting rules do not apply
+ */
+ HUGETLB_ANONHUGE_INODE = 2,
};
#ifdef CONFIG_HUGETLBFS
diff -puN mm/mmap.c~hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions mm/mmap.c
--- a/mm/mmap.c~hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions
+++ a/mm/mmap.c
@@ -30,6 +30,7 @@
#include <linux/ksm.h>
#include <linux/mmu_notifier.h>
#include <linux/perf_counter.h>
+#include <linux/hugetlb.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
@@ -950,6 +951,24 @@ unsigned long do_mmap_pgoff(struct file
if (mm->map_count > sysctl_max_map_count)
return -ENOMEM;
+ if (flags & MAP_HUGETLB) {
+ struct user_struct *user = NULL;
+ if (file)
+ return -EINVAL;
+
+ /*
+ * VM_NORESERVE is used because the reservations will be
+ * taken when vm_ops->mmap() is called
+ * A dummy user value is used because we are not locking
+ * memory so no accounting is necessary
+ */
+ len = ALIGN(len, huge_page_size(&default_hstate));
+ file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
+ &user, HUGETLB_ANONHUGE_INODE);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+ }
+
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
_
Patches currently in -mm which might be from ebmunson@xxxxxxxxxx are
hugetlbfs-allow-the-creation-of-files-suitable-for-map_private-on-the-vfs-internal-mount.patch
hugetlb-add-map_hugetlb-for-mmaping-pseudo-anonymous-huge-page-regions.patch
hugetlb-add-map_hugetlb-example.patch
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