From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 5331E6B0150 for ; Wed, 26 Aug 2009 06:54:52 -0400 (EDT) Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e38.co.us.ibm.com (8.14.3/8.13.1) with ESMTP id n7QAfH8L003308 for ; Wed, 26 Aug 2009 04:41:17 -0600 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n7QAj0cL167744 for ; Wed, 26 Aug 2009 04:45:00 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n7QAj0pr011769 for ; Wed, 26 Aug 2009 04:45:00 -0600 From: Eric B Munson Subject: [PATCH 1/3] hugetlbfs: Allow the creation of files suitable for MAP_PRIVATE on the vfs internal mount Date: Wed, 26 Aug 2009 11:44:51 +0100 Message-Id: <1c66a9e98a73d61c611e5cf09b276e954965046e.1251282769.git.ebmunson@us.ibm.com> In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Cc: linux-man@vger.kernel.org, mtk.manpages@gmail.com, randy.dunlap@oracle.com, Eric B Munson List-ID: There are two means of creating mappings backed by huge pages: 1. mmap() a file created on hugetlbfs 2. Use shm which creates a file on an internal mount which essentially maps it MAP_SHARED The internal mount is only used for shared mappings but there is very little that stops it being used for private mappings. This patch extends hugetlbfs_file_setup() to deal with the creation of files that will be mapped MAP_PRIVATE on the internal hugetlbfs mount. This extended API is used in a subsequent patch to implement the MAP_HUGETLB mmap() flag. Signed-off-by: Eric Munson --- fs/hugetlbfs/inode.c | 21 +++++++++++++++++---- include/linux/hugetlb.h | 12 ++++++++++-- ipc/shm.c | 2 +- 3 files changed, 28 insertions(+), 7 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index cb88dac..5584d55 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -506,6 +506,13 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; INIT_LIST_HEAD(&inode->i_mapping->private_list); info = HUGETLBFS_I(inode); + /* + * The policy is initialized here even if we are creating a + * private inode because initialization simply creates an + * an empty rb tree and calls spin_lock_init(), later when we + * call mpol_free_shared_policy() it will just return because + * the rb tree will still be empty. + */ mpol_shared_policy_init(&info->policy, NULL); switch (mode & S_IFMT) { default: @@ -930,13 +937,19 @@ static struct file_system_type hugetlbfs_fs_type = { static struct vfsmount *hugetlbfs_vfsmount; -static int can_do_hugetlb_shm(void) +static int can_do_hugetlb_shm(int creat_flags) { - return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); + if (creat_flags != HUGETLB_SHMFS_INODE) + return 0; + if (capable(CAP_IPC_LOCK)) + return 1; + if (in_group_p(sysctl_hugetlb_shm_group)) + return 1; + return 0; } struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, - struct user_struct **user) + struct user_struct **user, int creat_flags) { int error = -ENOMEM; struct file *file; @@ -948,7 +961,7 @@ struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, if (!hugetlbfs_vfsmount) return ERR_PTR(-ENOENT); - if (!can_do_hugetlb_shm()) { + if (!can_do_hugetlb_shm(creat_flags)) { *user = current_user(); if (user_shm_lock(size, *user)) { WARN_ONCE(1, diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 5cbc620..38bb552 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -110,6 +110,14 @@ static inline void hugetlb_report_meminfo(struct seq_file *m) #endif /* !CONFIG_HUGETLB_PAGE */ +enum { + /* + * The file will be used as an shm file so shmfs accounting rules + * apply + */ + HUGETLB_SHMFS_INODE = 1, +}; + #ifdef CONFIG_HUGETLBFS struct hugetlbfs_config { uid_t uid; @@ -148,7 +156,7 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb) extern const struct file_operations hugetlbfs_file_operations; extern struct vm_operations_struct hugetlb_vm_ops; struct file *hugetlb_file_setup(const char *name, size_t size, int acct, - struct user_struct **user); + struct user_struct **user, int creat_flags); int hugetlb_get_quota(struct address_space *mapping, long delta); void hugetlb_put_quota(struct address_space *mapping, long delta); @@ -170,7 +178,7 @@ static inline void set_file_hugepages(struct file *file) #define is_file_hugepages(file) 0 #define set_file_hugepages(file) BUG() -#define hugetlb_file_setup(name,size,acct,user) ERR_PTR(-ENOSYS) +#define hugetlb_file_setup(name,size,acct,user,creat) ERR_PTR(-ENOSYS) #endif /* !CONFIG_HUGETLBFS */ diff --git a/ipc/shm.c b/ipc/shm.c index 1bc4701..5ba4962 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -370,7 +370,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (shmflg & SHM_NORESERVE) acctflag = VM_NORESERVE; file = hugetlb_file_setup(name, size, acctflag, - &shp->mlock_user); + &shp->mlock_user, HUGETLB_SHMFS_INODE); } else { /* * Do not allow no accounting for OVERCOMMIT_NEVER, even -- 1.6.3.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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