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mempolicy: rework shmem mpol parsing and display

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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>
This commit is contained in:
Lee Schermerhorn
2008-04-28 02:13:23 -07:00
committed by Linus Torvalds
parent 2291990ab3
commit 095f1fc4eb
3 changed files with 135 additions and 106 deletions
Download Patch File Download Diff File Expand all files Collapse all files

116
mm/shmem.c
View File

@ -1079,108 +1079,22 @@ redirty:
#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 @@ static struct page *shmem_alloc_page(gfp_t gfp,
}
#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 @@ static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
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",