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| author | Eric B Munson <ebmunson@us.ibm.com> | 2009-09-21 17:03:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 07:17:42 -0700 |
| commit | 4e52780d41a741fb4861ae1df2413dd816ec11b1 (patch) | |
| tree | b3722349661ed0ce87841b110f568616892cf719 | |
| parent | 90f72aa58bbf076b68e289fbd71eb829bc505923 (diff) | |
| download | lwn-4e52780d41a741fb4861ae1df2413dd816ec11b1.tar.gz lwn-4e52780d41a741fb4861ae1df2413dd816ec11b1.zip | |
hugetlb: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions
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.
[akpm@linux-foundation.org: fix arch definitions of MAP_HUGETLB]
Signed-off-by: Eric B Munson <ebmunson@us.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/hugetlb.h | 7 | ||||
| -rw-r--r-- | mm/mmap.c | 18 |
2 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index f6505ad86657..176e7ee73eff 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -112,12 +112,19 @@ static inline void hugetlb_report_meminfo(struct seq_file *m) #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 --git a/mm/mmap.c b/mm/mmap.c index 1aeef6625e6a..21d4029a07b3 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -949,6 +949,24 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, 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. */ |