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author | Hugh Dickins <hugh@veritas.com> | 2009-02-24 20:51:52 +0000 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-25 12:21:42 -0800 |
commit | 0b0a0806b0d8635e046bf533225a25903b1cddce (patch) | |
tree | 245ac39eb1b7c6008a669ab2d68ed174d66bd7bc | |
parent | c15d8a6499d04e5d2cac07f8120f207bb275f60f (diff) | |
download | kernel_samsung_smdk4412-0b0a0806b0d8635e046bf533225a25903b1cddce.zip kernel_samsung_smdk4412-0b0a0806b0d8635e046bf533225a25903b1cddce.tar.gz kernel_samsung_smdk4412-0b0a0806b0d8635e046bf533225a25903b1cddce.tar.bz2 |
shmem: fix shared anonymous accounting
Each time I exit Firefox, /proc/meminfo's Committed_AS goes down almost
400 kB: OVERCOMMIT_NEVER would be allowing overcommits it should
prohibit.
Commit fc8744adc870a8d4366908221508bb113d8b72ee "Stop playing silly
games with the VM_ACCOUNT flag" changed shmem_file_setup() to set the
shmem file's VM_ACCOUNT flag according to VM_NORESERVE not being set in
the vma flags; but did so only _after_ the shmem_acct_size(flags, size)
call which is expected to pre-account a shared anonymous object.
It's all clearer if we switch shmem.c over to use VM_NORESERVE
throughout in place of !VM_ACCOUNT.
But I very nearly sent in a patch which mistakenly removed the
accounting from tmpfs files: shmem_get_inode()'s memset was good for not
setting VM_ACCOUNT, but now it needs to set VM_NORESERVE.
Rather than setting that by default, then perhaps clearing it again in
shmem_file_setup(), let's pass it as a flag to shmem_get_inode(): that
allows us to remove the #ifdef CONFIG_SHMEM from shmem_file_setup().
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/shmem.c | 43 |
1 files changed, 21 insertions, 22 deletions
@@ -169,13 +169,13 @@ static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) */ static inline int shmem_acct_size(unsigned long flags, loff_t size) { - return (flags & VM_ACCOUNT) ? - security_vm_enough_memory_kern(VM_ACCT(size)) : 0; + return (flags & VM_NORESERVE) ? + 0 : security_vm_enough_memory_kern(VM_ACCT(size)); } static inline void shmem_unacct_size(unsigned long flags, loff_t size) { - if (flags & VM_ACCOUNT) + if (!(flags & VM_NORESERVE)) vm_unacct_memory(VM_ACCT(size)); } @@ -187,13 +187,13 @@ static inline void shmem_unacct_size(unsigned long flags, loff_t size) */ static inline int shmem_acct_block(unsigned long flags) { - return (flags & VM_ACCOUNT) ? - 0 : security_vm_enough_memory_kern(VM_ACCT(PAGE_CACHE_SIZE)); + return (flags & VM_NORESERVE) ? + security_vm_enough_memory_kern(VM_ACCT(PAGE_CACHE_SIZE)) : 0; } static inline void shmem_unacct_blocks(unsigned long flags, long pages) { - if (!(flags & VM_ACCOUNT)) + if (flags & VM_NORESERVE) vm_unacct_memory(pages * VM_ACCT(PAGE_CACHE_SIZE)); } @@ -1515,8 +1515,8 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma) return 0; } -static struct inode * -shmem_get_inode(struct super_block *sb, int mode, dev_t dev) +static struct inode *shmem_get_inode(struct super_block *sb, int mode, + dev_t dev, unsigned long flags) { struct inode *inode; struct shmem_inode_info *info; @@ -1537,6 +1537,7 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev) info = SHMEM_I(inode); memset(info, 0, (char *)inode - (char *)info); spin_lock_init(&info->lock); + info->flags = flags & VM_NORESERVE; INIT_LIST_HEAD(&info->swaplist); switch (mode & S_IFMT) { @@ -1779,9 +1780,10 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) static int shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) { - struct inode *inode = shmem_get_inode(dir->i_sb, mode, dev); + struct inode *inode; int error = -ENOSPC; + inode = shmem_get_inode(dir->i_sb, mode, dev, VM_NORESERVE); if (inode) { error = security_inode_init_security(inode, dir, NULL, NULL, NULL); @@ -1920,7 +1922,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s if (len > PAGE_CACHE_SIZE) return -ENAMETOOLONG; - inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0); + inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE); if (!inode) return -ENOSPC; @@ -2332,7 +2334,7 @@ static int shmem_fill_super(struct super_block *sb, sb->s_flags |= MS_POSIXACL; #endif - inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0); + inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE); if (!inode) goto failed; inode->i_uid = sbinfo->uid; @@ -2574,12 +2576,12 @@ int shmem_unuse(swp_entry_t entry, struct page *page) return 0; } -#define shmem_file_operations ramfs_file_operations -#define shmem_vm_ops generic_file_vm_ops -#define shmem_get_inode ramfs_get_inode -#define shmem_acct_size(a, b) 0 -#define shmem_unacct_size(a, b) do {} while (0) -#define SHMEM_MAX_BYTES LLONG_MAX +#define shmem_vm_ops generic_file_vm_ops +#define shmem_file_operations ramfs_file_operations +#define shmem_get_inode(sb, mode, dev, flags) ramfs_get_inode(sb, mode, dev) +#define shmem_acct_size(flags, size) 0 +#define shmem_unacct_size(flags, size) do {} while (0) +#define SHMEM_MAX_BYTES LLONG_MAX #endif /* CONFIG_SHMEM */ @@ -2589,7 +2591,7 @@ int shmem_unuse(swp_entry_t entry, struct page *page) * shmem_file_setup - get an unlinked file living in tmpfs * @name: name for dentry (to be seen in /proc/<pid>/maps * @size: size to be set for the file - * @flags: vm_flags + * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size */ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) { @@ -2623,13 +2625,10 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) goto put_dentry; error = -ENOSPC; - inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0); + inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0, flags); if (!inode) goto close_file; -#ifdef CONFIG_SHMEM - SHMEM_I(inode)->flags = (flags & VM_NORESERVE) ? 0 : VM_ACCOUNT; -#endif d_instantiate(dentry, inode); inode->i_size = size; inode->i_nlink = 0; /* It is unlinked */ |