linux/include/linux/shmem_fs.h
Robin Holt 7339ff8302 [PATCH] Add tmpfs options for memory placement policies
Anything that writes into a tmpfs filesystem is liable to disproportionately
decrease the available memory on a particular node.  Since there's no telling
what sort of application (e.g.  dd/cp/cat) might be dropping large files
there, this lets the admin choose the appropriate default behavior for their
site's situation.

Introduce a tmpfs mount option which allows specifying a memory policy and
a second option to specify the nodelist for that policy.  With the default
policy, tmpfs will behave as it does today.  This patch adds support for
preferred, bind, and interleave policies.

The default policy will cause pages to be added to tmpfs files on the node
which is doing the writing.  Some jobs expect a single process to create
and manage the tmpfs files.  This results in a node which has a
significantly reduced number of free pages.

With this patch, the administrator can specify the policy and nodes for
that policy where they would prefer allocations.

This patch was originally written by Brent Casavant and Hugh Dickins.  I
added support for the bind and preferred policies and the mpol_nodelist
mount option.

Signed-off-by: Brent Casavant <bcasavan@sgi.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:27:07 -08:00

40 lines
1.2 KiB
C

#ifndef __SHMEM_FS_H
#define __SHMEM_FS_H
#include <linux/swap.h>
#include <linux/mempolicy.h>
/* inode in-kernel data */
#define SHMEM_NR_DIRECT 16
struct shmem_inode_info {
spinlock_t lock;
unsigned long flags;
unsigned long alloced; /* data pages alloced to file */
unsigned long swapped; /* subtotal assigned to swap */
unsigned long next_index; /* highest alloced index + 1 */
struct shared_policy policy; /* NUMA memory alloc policy */
struct page *i_indirect; /* top indirect blocks page */
swp_entry_t i_direct[SHMEM_NR_DIRECT]; /* first blocks */
struct list_head swaplist; /* chain of maybes on swap */
struct inode vfs_inode;
};
struct shmem_sb_info {
unsigned long max_blocks; /* How many blocks are allowed */
unsigned long free_blocks; /* How many are left for allocation */
unsigned long max_inodes; /* How many inodes are allowed */
unsigned long free_inodes; /* How many are left for allocation */
int policy; /* Default NUMA memory alloc policy */
nodemask_t policy_nodes; /* nodemask for preferred and bind */
spinlock_t stat_lock;
};
static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
{
return container_of(inode, struct shmem_inode_info, vfs_inode);
}
#endif