5a6e75f811
This patch adds new mount option "huge=". It can have following values: - "always": Attempt to allocate huge pages every time we need a new page; - "never": Do not allocate huge pages; - "within_size": Only allocate huge page if it will be fully within i_size. Also respect fadvise()/madvise() hints; - "advise: Only allocate huge pages if requested with fadvise()/madvise(); Default is "never" for now. "mount -o remount,huge= /mountpoint" works fine after mount: remounting huge=never will not attempt to break up huge pages at all, just stop more from being allocated. No new config option: put this under CONFIG_TRANSPARENT_HUGEPAGE, which is the appropriate option to protect those who don't want the new bloat, and with which we shall share some pmd code. Prohibit the option when !CONFIG_TRANSPARENT_HUGEPAGE, just as mpol is invalid without CONFIG_NUMA (was hidden in mpol_parse_str(): make it explicit). Allow enabling THP only if the machine has_transparent_hugepage(). But what about Shmem with no user-visible mount? SysV SHM, memfds, shared anonymous mmaps (of /dev/zero or MAP_ANONYMOUS), GPU drivers' DRM objects, Ashmem. Though unlikely to suit all usages, provide sysfs knob /sys/kernel/mm/transparent_hugepage/shmem_enabled to experiment with huge on those. And allow shmem_enabled two further values: - "deny": For use in emergencies, to force the huge option off from all mounts; - "force": Force the huge option on for all - very useful for testing; Based on patch by Hugh Dickins. Link: http://lkml.kernel.org/r/1466021202-61880-28-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
88 lines
3.0 KiB
C
88 lines
3.0 KiB
C
#ifndef __SHMEM_FS_H
|
|
#define __SHMEM_FS_H
|
|
|
|
#include <linux/file.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/mempolicy.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/percpu_counter.h>
|
|
#include <linux/xattr.h>
|
|
|
|
/* inode in-kernel data */
|
|
|
|
struct shmem_inode_info {
|
|
spinlock_t lock;
|
|
unsigned int seals; /* shmem seals */
|
|
unsigned long flags;
|
|
unsigned long alloced; /* data pages alloced to file */
|
|
unsigned long swapped; /* subtotal assigned to swap */
|
|
struct shared_policy policy; /* NUMA memory alloc policy */
|
|
struct list_head swaplist; /* chain of maybes on swap */
|
|
struct simple_xattrs xattrs; /* list of xattrs */
|
|
struct inode vfs_inode;
|
|
};
|
|
|
|
struct shmem_sb_info {
|
|
unsigned long max_blocks; /* How many blocks are allowed */
|
|
struct percpu_counter used_blocks; /* How many are allocated */
|
|
unsigned long max_inodes; /* How many inodes are allowed */
|
|
unsigned long free_inodes; /* How many are left for allocation */
|
|
spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
|
|
umode_t mode; /* Mount mode for root directory */
|
|
unsigned char huge; /* Whether to try for hugepages */
|
|
kuid_t uid; /* Mount uid for root directory */
|
|
kgid_t gid; /* Mount gid for root directory */
|
|
struct mempolicy *mpol; /* default memory policy for mappings */
|
|
};
|
|
|
|
static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
|
|
{
|
|
return container_of(inode, struct shmem_inode_info, vfs_inode);
|
|
}
|
|
|
|
/*
|
|
* Functions in mm/shmem.c called directly from elsewhere:
|
|
*/
|
|
extern int shmem_init(void);
|
|
extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
|
|
extern struct file *shmem_file_setup(const char *name,
|
|
loff_t size, unsigned long flags);
|
|
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 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);
|
|
extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
|
|
pgoff_t index, gfp_t gfp_mask);
|
|
extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
|
|
extern int shmem_unuse(swp_entry_t entry, struct page *page);
|
|
|
|
extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
|
|
extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
|
|
pgoff_t start, pgoff_t end);
|
|
|
|
static inline struct page *shmem_read_mapping_page(
|
|
struct address_space *mapping, pgoff_t index)
|
|
{
|
|
return shmem_read_mapping_page_gfp(mapping, index,
|
|
mapping_gfp_mask(mapping));
|
|
}
|
|
|
|
#ifdef CONFIG_TMPFS
|
|
|
|
extern int shmem_add_seals(struct file *file, unsigned int seals);
|
|
extern int shmem_get_seals(struct file *file);
|
|
extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg);
|
|
|
|
#else
|
|
|
|
static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif
|