mm: proc: move show_numa_map() to fs/proc/task_mmu.c

Moving show_numa_map() from mempolicy.c to task_mmu.c solves several
issues.

  - Having the show() operation "miles away" from the corresponding
    seq_file iteration operations is a maintenance burden.

  - The need to export ad hoc info like struct proc_maps_private is
    eliminated.

  - The implementation of show_numa_map() can be improved in a simple
    manner by cooperating with the other seq_file operations (start,
    stop, etc) -- something that would be messy to do without this
    change.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 182 insertions, 2 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 318d8654989b..2ed53d18b2ef 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -858,8 +858,188 @@ const struct file_operations proc_pagemap_operations = {
 #endif /* CONFIG_PROC_PAGE_MONITOR */
 
 #ifdef CONFIG_NUMA
-extern int show_numa_map(struct seq_file *m, void *v);
 
+struct numa_maps {
+        struct vm_area_struct *vma;
+        unsigned long pages;
+        unsigned long anon;
+        unsigned long active;
+        unsigned long writeback;
+        unsigned long mapcount_max;
+        unsigned long dirty;
+        unsigned long swapcache;
+        unsigned long node[MAX_NUMNODES];
+};
+
+static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty)
+{
+        int count = page_mapcount(page);
+
+        md->pages++;
+        if (pte_dirty || PageDirty(page))
+                md->dirty++;
+
+        if (PageSwapCache(page))
+                md->swapcache++;
+
+        if (PageActive(page) || PageUnevictable(page))
+                md->active++;
+
+        if (PageWriteback(page))
+                md->writeback++;
+
+        if (PageAnon(page))
+                md->anon++;
+
+        if (count > md->mapcount_max)
+                md->mapcount_max = count;
+
+        md->node[page_to_nid(page)]++;
+}
+
+static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
+                unsigned long end, struct mm_walk *walk)
+{
+        struct numa_maps *md;
+        spinlock_t *ptl;
+        pte_t *orig_pte;
+        pte_t *pte;
+
+        md = walk->private;
+        orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+        do {
+                struct page *page;
+                int nid;
+
+                if (!pte_present(*pte))
+                        continue;
+
+                page = vm_normal_page(md->vma, addr, *pte);
+                if (!page)
+                        continue;
+
+                if (PageReserved(page))
+                        continue;
+
+                nid = page_to_nid(page);
+                if (!node_isset(nid, node_states[N_HIGH_MEMORY]))
+                        continue;
+
+                gather_stats(page, md, pte_dirty(*pte));
+
+        } while (pte++, addr += PAGE_SIZE, addr != end);
+        pte_unmap_unlock(orig_pte, ptl);
+        return 0;
+}
+#ifdef CONFIG_HUGETLB_PAGE
+static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
+                unsigned long addr, unsigned long end, struct mm_walk *walk)
+{
+        struct numa_maps *md;
+        struct page *page;
+
+        if (pte_none(*pte))
+                return 0;
+
+        page = pte_page(*pte);
+        if (!page)
+                return 0;
+
+        md = walk->private;
+        gather_stats(page, md, pte_dirty(*pte));
+        return 0;
+}
+
+#else
+static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
+                unsigned long addr, unsigned long end, struct mm_walk *walk)
+{
+        return 0;
+}
+#endif
+
+/*
+ * Display pages allocated per node and memory policy via /proc.
+ */
+static int show_numa_map(struct seq_file *m, void *v)
+{
+        struct proc_maps_private *priv = m->private;
+        struct vm_area_struct *vma = v;
+        struct numa_maps *md;
+        struct file *file = vma->vm_file;
+        struct mm_struct *mm = vma->vm_mm;
+        struct mm_walk walk = {};
+        struct mempolicy *pol;
+        int n;
+        char buffer[50];
+
+        if (!mm)
+                return 0;
+
+        md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL);
+        if (!md)
+                return 0;
+
+        md->vma = vma;
+
+        walk.hugetlb_entry = gather_hugetbl_stats;
+        walk.pmd_entry = gather_pte_stats;
+        walk.private = md;
+        walk.mm = mm;
+
+        pol = get_vma_policy(priv->task, vma, vma->vm_start);
+        mpol_to_str(buffer, sizeof(buffer), pol, 0);
+        mpol_cond_put(pol);
+
+        seq_printf(m, "%08lx %s", vma->vm_start, buffer);
+
+        if (file) {
+                seq_printf(m, " file=");
+                seq_path(m, &file->f_path, "\n\t= ");
+        } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
+                seq_printf(m, " heap");
+        } else if (vma->vm_start <= mm->start_stack &&
+                        vma->vm_end >= mm->start_stack) {
+                seq_printf(m, " stack");
+        }
+
+        walk_page_range(vma->vm_start, vma->vm_end, &walk);
+
+        if (!md->pages)
+                goto out;
+
+        if (md->anon)
+                seq_printf(m, " anon=%lu", md->anon);
+
+        if (md->dirty)
+                seq_printf(m, " dirty=%lu", md->dirty);
+
+        if (md->pages != md->anon && md->pages != md->dirty)
+                seq_printf(m, " mapped=%lu", md->pages);
+
+        if (md->mapcount_max > 1)
+                seq_printf(m, " mapmax=%lu", md->mapcount_max);
+
+        if (md->swapcache)
+                seq_printf(m, " swapcache=%lu", md->swapcache);
+
+        if (md->active < md->pages && !is_vm_hugetlb_page(vma))
+                seq_printf(m, " active=%lu", md->active);
+
+        if (md->writeback)
+                seq_printf(m, " writeback=%lu", md->writeback);
+
+        for_each_node_state(n, N_HIGH_MEMORY)
+                if (md->node[n])
+                        seq_printf(m, " N%d=%lu", n, md->node[n]);
+out:
+        seq_putc(m, '\n');
+        kfree(md);
+
+        if (m->count < m->size)
+                m->version = (vma != priv->tail_vma) ? vma->vm_start : 0;
+        return 0;
+}
 static const struct seq_operations proc_pid_numa_maps_op = {
         .start  = m_start,
         .next   = m_next,
@@ -878,4 +1058,4 @@ const struct file_operations proc_numa_maps_operations = {
         .llseek         = seq_lseek,
         .release        = seq_release_private,
 };
-#endif
+#endif /* CONFIG_NUMA */