* [PATCH 2/2 v5][rfc] tmpfs: interleave the starting node of /dev/shmem
2012-07-03 19:44 ` [PATCH 1/2 v5][rfc] shmem: provide vm_ops when also providing a mem policy Nathan Zimmer
@ 2012-07-03 19:44 ` Nathan Zimmer
0 siblings, 0 replies; 3+ messages in thread
From: Nathan Zimmer @ 2012-07-03 19:44 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: Nathan Zimmer, Christoph Lameter, Nick Piggin, Hugh Dickins,
Lee Schermerhorn, KOSAKI Motohiro, Rik van Riel
The tmpfs superblock grants an offset for each inode as they are created. Each
inode then uses that offset to provide a preferred first node for its interleave
in the newly provided shmem_interleave.
Cc: Christoph Lameter <cl@linux.com>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
---
include/linux/mm.h | 7 +++++++
include/linux/shmem_fs.h | 3 +++
mm/mempolicy.c | 4 ++++
mm/shmem.c | 17 +++++++++++++++++
4 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b36d08c..651109e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -238,6 +238,13 @@ struct vm_operations_struct {
*/
struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
unsigned long addr);
+
+ /*
+ * If the policy is interleave allow the vma to suggest a node.
+ */
+ unsigned long (*interleave)(struct vm_area_struct *vma,
+ unsigned long addr);
+
int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
const nodemask_t *to, unsigned long flags);
#endif
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index bef2cf0..6995556 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -17,6 +17,7 @@ struct shmem_inode_info {
char *symlink; /* unswappable short symlink */
};
struct shared_policy policy; /* NUMA memory alloc policy */
+ unsigned long node_offset; /* bias for interleaved nodes */
struct list_head swaplist; /* chain of maybes on swap */
struct list_head xattr_list; /* list of shmem_xattr */
struct inode vfs_inode;
@@ -32,6 +33,8 @@ struct shmem_sb_info {
kgid_t gid; /* Mount gid for root directory */
umode_t mode; /* Mount mode for root directory */
struct mempolicy *mpol; /* default memory policy for mappings */
+ unsigned long next_pref_node;
+ /* next interleave bias to suggest for inodes */
};
static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 1d771e4..e2cbe9e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1663,6 +1663,10 @@ static inline unsigned interleave_nid(struct mempolicy *pol,
{
if (vma) {
unsigned long off;
+ if (vma->vm_ops && vma->vm_ops->interleave) {
+ off = vma->vm_ops->interleave(vma, addr);
+ return offset_il_node(pol, vma, off);
+ }
/*
* for small pages, there is no difference between
diff --git a/mm/shmem.c b/mm/shmem.c
index d073252..e569338 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -922,6 +922,7 @@ static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp,
pvma.vm_start = 0;
pvma.vm_pgoff = index;
pvma.vm_policy = spol;
+ pvma.vm_private_data = (void *) info->node_offset;
if (pvma.vm_policy)
pvma.vm_ops = &shmem_vm_ops;
else
@@ -938,6 +939,7 @@ static struct page *shmem_alloc_page(gfp_t gfp,
pvma.vm_start = 0;
pvma.vm_pgoff = index;
pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index);
+ pvma.vm_private_data = (void *) info->node_offset;
if (pvma.vm_policy)
pvma.vm_ops = &shmem_vm_ops;
else
@@ -1314,6 +1316,19 @@ static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index);
}
+
+static unsigned long shmem_interleave(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ unsigned long offset;
+
+ /* Use the vm_files prefered node as the initial offset. */
+ offset = (unsigned long *) vma->vm_private_data;
+
+ offset += ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+
+ return offset;
+}
#endif
int shmem_lock(struct file *file, int lock, struct user_struct *user)
@@ -1386,6 +1401,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
inode->i_fop = &shmem_file_operations;
mpol_shared_policy_init(&info->policy,
shmem_get_sbmpol(sbinfo));
+ info->node_offset = ++(sbinfo->next_pref_node);
break;
case S_IFDIR:
inc_nlink(inode);
@@ -2871,6 +2887,7 @@ static const struct super_operations shmem_ops = {
static const struct vm_operations_struct shmem_vm_ops = {
.fault = shmem_fault,
#ifdef CONFIG_NUMA
+ .interleave = shmem_interleave,
.set_policy = shmem_set_policy,
.get_policy = shmem_get_policy,
#endif
--
1.6.0.2
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