[PATCH] Fold numa_maps into mempolicies.c

First discussed at http://marc.theaimsgroup.com/?t=113149255100001&r=1&w=2

- Use the check_range() in mempolicy.c to gather statistics.

- Improve the numa_maps code in general and fix some comments.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 142 insertions, 123 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 50bd5a8f0446..0eaad41f4658 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -390,129 +390,12 @@ struct seq_operations proc_pid_smaps_op = {
 };
 
 #ifdef CONFIG_NUMA
-
-struct numa_maps {
-        unsigned long pages;
-        unsigned long anon;
-        unsigned long mapped;
-        unsigned long mapcount_max;
-        unsigned long node[MAX_NUMNODES];
-};
-
-/*
- * Calculate numa node maps for a vma
- */
-static struct numa_maps *get_numa_maps(struct vm_area_struct *vma)
-{
-        int i;
-        struct page *page;
-        unsigned long vaddr;
-        struct numa_maps *md = kmalloc(sizeof(struct numa_maps), GFP_KERNEL);
-
-        if (!md)
-                return NULL;
-        md->pages = 0;
-        md->anon = 0;
-        md->mapped = 0;
-        md->mapcount_max = 0;
-        for_each_node(i)
-                md->node[i] =0;
-
-        for (vaddr = vma->vm_start; vaddr < vma->vm_end; vaddr += PAGE_SIZE) {
-                page = follow_page(vma, vaddr, 0);
-                if (page) {
-                        int count = page_mapcount(page);
-
-                        if (count)
-                                md->mapped++;
-                        if (count > md->mapcount_max)
-                                md->mapcount_max = count;
-                        md->pages++;
-                        if (PageAnon(page))
-                                md->anon++;
-                        md->node[page_to_nid(page)]++;
-                }
-                cond_resched();
-        }
-        return md;
-}
-
-static int show_numa_map(struct seq_file *m, void *v)
-{
-        struct task_struct *task = m->private;
-        struct vm_area_struct *vma = v;
-        struct mempolicy *pol;
-        struct numa_maps *md;
-        struct zone **z;
-        int n;
-        int first;
-
-        if (!vma->vm_mm)
-                return 0;
-
-        md = get_numa_maps(vma);
-        if (!md)
-                return 0;
-
-        seq_printf(m, "%08lx", vma->vm_start);
-        pol = get_vma_policy(task, vma, vma->vm_start);
-        /* Print policy */
-        switch (pol->policy) {
-        case MPOL_PREFERRED:
-                seq_printf(m, " prefer=%d", pol->v.preferred_node);
-                break;
-        case MPOL_BIND:
-                seq_printf(m, " bind={");
-                first = 1;
-                for (z = pol->v.zonelist->zones; *z; z++) {
-
-                        if (!first)
-                                seq_putc(m, ',');
-                        else
-                                first = 0;
-                        seq_printf(m, "%d/%s", (*z)->zone_pgdat->node_id,
-                                        (*z)->name);
-                }
-                seq_putc(m, '}');
-                break;
-        case MPOL_INTERLEAVE:
-                seq_printf(m, " interleave={");
-                first = 1;
-                for_each_node(n) {
-                        if (node_isset(n, pol->v.nodes)) {
-                                if (!first)
-                                        seq_putc(m,',');
-                                else
-                                        first = 0;
-                                seq_printf(m, "%d",n);
-                        }
-                }
-                seq_putc(m, '}');
-                break;
-        default:
-                seq_printf(m," default");
-                break;
-        }
-        seq_printf(m, " MaxRef=%lu Pages=%lu Mapped=%lu",
-                        md->mapcount_max, md->pages, md->mapped);
-        if (md->anon)
-                seq_printf(m," Anon=%lu",md->anon);
-
-        for_each_online_node(n) {
-                if (md->node[n])
-                        seq_printf(m, " N%d=%lu", n, md->node[n]);
-        }
-        seq_putc(m, '\n');
-        kfree(md);
-        if (m->count < m->size)  /* vma is copied successfully */
-                m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
-        return 0;
-}
+extern int show_numa_map(struct seq_file *m, void *v);
 
 struct seq_operations proc_pid_numa_maps_op = {
-        .start  = m_start,
-        .next   = m_next,
-        .stop   = m_stop,
-        .show   = show_numa_map
+        .start  = m_start,
+        .next   = m_next,
+        .stop   = m_stop,
+        .show   = show_numa_map
 };
 #endif
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 270e9a39ec15..44b9d69900bc 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -84,6 +84,8 @@
 #include <linux/compat.h>
 #include <linux/mempolicy.h>
 #include <linux/swap.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
 
 #include <asm/tlbflush.h>
 #include <asm/uaccess.h>
@@ -91,6 +93,7 @@
 /* Internal flags */
 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0)    /* Skip checks for continuous vmas */
 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1)          /* Invert check for nodemask */
+#define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2)           /* Gather statistics */
 
 static kmem_cache_t *policy_cache;
 static kmem_cache_t *sn_cache;
@@ -228,6 +231,8 @@ static void migrate_page_add(struct vm_area_struct *vma,
         }
 }
 
+static void gather_stats(struct page *, void *);
+
 /* Scan through pages checking if pages follow certain conditions. */
 static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                 unsigned long addr, unsigned long end,
@@ -252,7 +257,9 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
                         continue;
 
-                if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+                if (flags & MPOL_MF_STATS)
+                        gather_stats(page, private);
+                else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
                         migrate_page_add(vma, page, private, flags);
                 else
                         break;
@@ -1460,3 +1467,132 @@ void numa_policy_rebind(const nodemask_t *old, const nodemask_t *new)
 {
         rebind_policy(current->mempolicy, old, new);
 }
+
+/*
+ * Display pages allocated per node and memory policy via /proc.
+ */
+
+static const char *policy_types[] = { "default", "prefer", "bind",
+                                      "interleave" };
+
+/*
+ * Convert a mempolicy into a string.
+ * Returns the number of characters in buffer (if positive)
+ * or an error (negative)
+ */
+static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
+{
+        char *p = buffer;
+        int l;
+        nodemask_t nodes;
+        int mode = pol ? pol->policy : MPOL_DEFAULT;
+
+        switch (mode) {
+        case MPOL_DEFAULT:
+                nodes_clear(nodes);
+                break;
+
+        case MPOL_PREFERRED:
+                nodes_clear(nodes);
+                node_set(pol->v.preferred_node, nodes);
+                break;
+
+        case MPOL_BIND:
+                get_zonemask(pol, &nodes);
+                break;
+
+        case MPOL_INTERLEAVE:
+                nodes = pol->v.nodes;
+                break;
+
+        default:
+                BUG();
+                return -EFAULT;
+        }
+
+        l = strlen(policy_types[mode]);
+        if (buffer + maxlen < p + l + 1)
+                return -ENOSPC;
+
+        strcpy(p, policy_types[mode]);
+        p += l;
+
+        if (!nodes_empty(nodes)) {
+                if (buffer + maxlen < p + 2)
+                        return -ENOSPC;
+                *p++ = '=';
+                p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
+        }
+        return p - buffer;
+}
+
+struct numa_maps {
+        unsigned long pages;
+        unsigned long anon;
+        unsigned long mapped;
+        unsigned long mapcount_max;
+        unsigned long node[MAX_NUMNODES];
+};
+
+static void gather_stats(struct page *page, void *private)
+{
+        struct numa_maps *md = private;
+        int count = page_mapcount(page);
+
+        if (count)
+                md->mapped++;
+
+        if (count > md->mapcount_max)
+                md->mapcount_max = count;
+
+        md->pages++;
+
+        if (PageAnon(page))
+                md->anon++;
+
+        md->node[page_to_nid(page)]++;
+        cond_resched();
+}
+
+int show_numa_map(struct seq_file *m, void *v)
+{
+        struct task_struct *task = m->private;
+        struct vm_area_struct *vma = v;
+        struct numa_maps *md;
+        int n;
+        char buffer[50];
+
+        if (!vma->vm_mm)
+                return 0;
+
+        md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL);
+        if (!md)
+                return 0;
+
+        check_pgd_range(vma, vma->vm_start, vma->vm_end,
+                    &node_online_map, MPOL_MF_STATS, md);
+
+        if (md->pages) {
+                mpol_to_str(buffer, sizeof(buffer),
+                            get_vma_policy(task, vma, vma->vm_start));
+
+                seq_printf(m, "%08lx %s pages=%lu mapped=%lu maxref=%lu",
+                           vma->vm_start, buffer, md->pages,
+                           md->mapped, md->mapcount_max);
+
+                if (md->anon)
+                        seq_printf(m," anon=%lu",md->anon);
+
+                for_each_online_node(n)
+                        if (md->node[n])
+                                seq_printf(m, " N%d=%lu", n, md->node[n]);
+
+                seq_putc(m, '\n');
+        }
+        kfree(md);
+
+        if (m->count < m->size)
+                m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
+        return 0;
+}
+