mempolicy: rework shmem mpol parsing and display
mm/shmem.c currently contains functions to parse and display memory policy
strings for the tmpfs 'mpol' mount option. Move this to mm/mempolicy.c with
the rest of the mempolicy support. With subsequent patches, we'll be able to
remove knowledge of the details [mode, flags, policy, ...] completely from
shmem.c
1) replace shmem_parse_mpol() in mm/shmem.c with mpol_parse_str() in
mm/mempolicy.c. Rework to use the policy_types[] array [used by
mpol_to_str()] to look up mode by name.
2) use mpol_to_str() to format policy for shmem_show_mpol(). mpol_to_str()
expects a pointer to a struct mempolicy, so temporarily construct one.
This will be replaced with a reference to a struct mempolicy in the tmpfs
superblock in a subsequent patch.
NOTE 1: I changed mpol_to_str() to use a colon ':' rather than an equal
sign '=' as the nodemask delimiter to match mpol_parse_str() and the
tmpfs/shmem mpol mount option formatting that now uses mpol_to_str(). This
is a user visible change to numa_maps, but then the addition of the mode
flags already changed the display. It makes sense to me to have the mounts
and numa_maps display the policy in the same format. However, if anyone
objects strongly, I can pass the desired nodemask delimeter as an arg to
mpol_to_str().
Note 2: Like show_numa_map(), I don't check the return code from
mpol_to_str(). I do use a longer buffer than the one provided by
show_numa_map(), which seems to have sufficed so far.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index 0b591c66..3c620dc 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1079,108 +1079,22 @@
#ifdef CONFIG_NUMA
#ifdef CONFIG_TMPFS
-static int shmem_parse_mpol(char *value, unsigned short *policy,
- unsigned short *mode_flags, nodemask_t *policy_nodes)
-{
- char *nodelist = strchr(value, ':');
- char *flags = strchr(value, '=');
- int err = 1;
-
- if (nodelist) {
- /* NUL-terminate policy string */
- *nodelist++ = '\0';
- if (nodelist_parse(nodelist, *policy_nodes))
- goto out;
- if (!nodes_subset(*policy_nodes, node_states[N_HIGH_MEMORY]))
- goto out;
- }
- if (flags)
- *flags++ = '\0';
- if (!strcmp(value, "default")) {
- *policy = MPOL_DEFAULT;
- /* Don't allow a nodelist */
- if (!nodelist)
- err = 0;
- } else if (!strcmp(value, "prefer")) {
- *policy = MPOL_PREFERRED;
- /* Insist on a nodelist of one node only */
- if (nodelist) {
- char *rest = nodelist;
- while (isdigit(*rest))
- rest++;
- if (!*rest)
- err = 0;
- }
- } else if (!strcmp(value, "bind")) {
- *policy = MPOL_BIND;
- /* Insist on a nodelist */
- if (nodelist)
- err = 0;
- } else if (!strcmp(value, "interleave")) {
- *policy = MPOL_INTERLEAVE;
- /*
- * Default to online nodes with memory if no nodelist
- */
- if (!nodelist)
- *policy_nodes = node_states[N_HIGH_MEMORY];
- err = 0;
- }
-
- *mode_flags = 0;
- if (flags) {
- /*
- * Currently, we only support two mutually exclusive
- * mode flags.
- */
- if (!strcmp(flags, "static"))
- *mode_flags |= MPOL_F_STATIC_NODES;
- else if (!strcmp(flags, "relative"))
- *mode_flags |= MPOL_F_RELATIVE_NODES;
- else
- err = 1; /* unrecognized flag */
- }
-out:
- /* Restore string for error message */
- if (nodelist)
- *--nodelist = ':';
- if (flags)
- *--flags = '=';
- return err;
-}
-
-static void shmem_show_mpol(struct seq_file *seq, unsigned short policy,
+static void shmem_show_mpol(struct seq_file *seq, unsigned short mode,
unsigned short flags, const nodemask_t policy_nodes)
{
- char *policy_string;
+ struct mempolicy temp;
+ char buffer[64];
- switch (policy) {
- case MPOL_PREFERRED:
- policy_string = "prefer";
- break;
- case MPOL_BIND:
- policy_string = "bind";
- break;
- case MPOL_INTERLEAVE:
- policy_string = "interleave";
- break;
- default:
- /* MPOL_DEFAULT */
- return;
- }
+ if (mode == MPOL_DEFAULT)
+ return; /* show nothing */
- seq_printf(seq, ",mpol=%s", policy_string);
+ temp.mode = mode;
+ temp.flags = flags;
+ temp.v.nodes = policy_nodes;
- if (policy != MPOL_INTERLEAVE ||
- !nodes_equal(policy_nodes, node_states[N_HIGH_MEMORY])) {
- char buffer[64];
- int len;
+ mpol_to_str(buffer, sizeof(buffer), &temp);
- len = nodelist_scnprintf(buffer, sizeof(buffer), policy_nodes);
- if (len < sizeof(buffer))
- seq_printf(seq, ":%s", buffer);
- else
- seq_printf(seq, ":?");
- }
+ seq_printf(seq, ",mpol=%s", buffer);
}
#endif /* CONFIG_TMPFS */
@@ -1221,12 +1135,6 @@
}
#else /* !CONFIG_NUMA */
#ifdef CONFIG_TMPFS
-static inline int shmem_parse_mpol(char *value, unsigned short *policy,
- unsigned short *mode_flags, nodemask_t *policy_nodes)
-{
- return 1;
-}
-
static inline void shmem_show_mpol(struct seq_file *seq, unsigned short policy,
unsigned short flags, const nodemask_t policy_nodes)
{
@@ -2231,8 +2139,8 @@
if (*rest)
goto bad_val;
} else if (!strcmp(this_char,"mpol")) {
- if (shmem_parse_mpol(value, &sbinfo->policy,
- &sbinfo->flags, &sbinfo->policy_nodes))
+ if (mpol_parse_str(value, &sbinfo->policy,
+ &sbinfo->flags, &sbinfo->policy_nodes))
goto bad_val;
} else {
printk(KERN_ERR "tmpfs: Bad mount option %s\n",