mem2node.c

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#include <errno.h>
#include <inttypes.h>
#include <linux/bitmap.h>
#include "mem2node.h"
#include "util.h"

struct phys_entry {
    struct rb_node  rb_node;
    u64 start;
    u64 end;
    u64 node;
};

static void phys_entry__insert(struct phys_entry *entry, struct rb_root *root)
{
    struct rb_node **p = &root->rb_node;
    struct rb_node *parent = NULL;
    struct phys_entry *e;

    while (*p != NULL) {
        parent = *p;
        e = rb_entry(parent, struct phys_entry, rb_node);

        if (entry->start < e->start)
            p = &(*p)->rb_left;
        else
            p = &(*p)->rb_right;
    }

    rb_link_node(&entry->rb_node, parent, p);
    rb_insert_color(&entry->rb_node, root);
}

static void
phys_entry__init(struct phys_entry *entry, u64 start, u64 bsize, u64 node)
{
    entry->start = start;
    entry->end   = start + bsize;
    entry->node  = node;
    RB_CLEAR_NODE(&entry->rb_node);
}

int mem2node__init(struct mem2node *map, struct perf_env *env)
{
    struct memory_node *n, *nodes = &env->memory_nodes[0];
    struct phys_entry *entries, *tmp_entries;
    u64 bsize = env->memory_bsize;
    int i, j = 0, max = 0;

    memset(map, 0x0, sizeof(*map));
    map->root = RB_ROOT;

    for (i = 0; i < env->nr_memory_nodes; i++) {
        n = &nodes[i];
        max += bitmap_weight(n->set, n->size);
    }

    entries = zalloc(sizeof(*entries) * max);
    if (!entries)
        return -ENOMEM;

    for (i = 0; i < env->nr_memory_nodes; i++) {
        u64 bit;

        n = &nodes[i];

        for (bit = 0; bit < n->size; bit++) {
            u64 start;

            if (!test_bit(bit, n->set))
                continue;

            start = bit * bsize;

            /*
             * Merge nearby areas, we walk in order
             * through the bitmap, so no need to sort.
             */
            if (j > 0) {
                struct phys_entry *prev = &entries[j - 1];

                if ((prev->end == start) &&
                    (prev->node == n->node)) {
                    prev->end += bsize;
                    continue;
                }
            }

            phys_entry__init(&entries[j++], start, bsize, n->node);
        }
    }

    /* Cut unused entries, due to merging. */
    tmp_entries = realloc(entries, sizeof(*entries) * j);
    if (tmp_entries)
        entries = tmp_entries;

    for (i = 0; i < j; i++) {
        pr_debug("mem2node %03" PRIu64 " [0x%016" PRIx64 "-0x%016" PRIx64 "]\n",
             entries[i].node, entries[i].start, entries[i].end);

        phys_entry__insert(&entries[i], &map->root);
    }

    map->entries = entries;
    return 0;
}

void mem2node__exit(struct mem2node *map)
{
    zfree(&map->entries);
}

int mem2node__node(struct mem2node *map, u64 addr)
{
    struct rb_node **p, *parent = NULL;
    struct phys_entry *entry;

    p = &map->root.rb_node;
    while (*p != NULL) {
        parent = *p;
        entry = rb_entry(parent, struct phys_entry, rb_node);
        if (addr < entry->start)
            p = &(*p)->rb_left;
        else if (addr >= entry->end)
            p = &(*p)->rb_right;
        else
            goto out;
    }

    entry = NULL;
out:
    return entry ? (int) entry->node : -1;
}