内存管理-31-系统内存统计-3-/proc/zoneinfo

基于msm-5.4

一、概述

/proc/zoneinfo 节点包含当前系统所有内存管理区的信息。

1. 打印内容

# cat /proc/zoneinfo
Node 0, zone   Normal          //Normal内存区
/* 第(1)部分，打印的是全局变量 vm_node_stat[i] 的值 */
  per-node stats
      nr_inactive_anon 152477
      nr_active_anon 749181
      nr_inactive_file 1028670
      nr_active_file 143843
      nr_unevictable 826
      nr_slab_reclaimable 50752
      nr_slab_unreclaimable 190516
      nr_isolated_anon 0
      nr_isolated_file 0
      workingset_nodes 29087
      workingset_refault 1824839
      workingset_activate 16816
      workingset_restore 204
      workingset_nodereclaim 0
      nr_anon_pages 883523
      nr_mapped    361497
      nr_file_pages 1205571
      nr_dirty     133
      nr_writeback 0
      nr_writeback_temp 0
      nr_shmem     18356
      nr_shmem_hugepages 0
      nr_shmem_pmdmapped 0
      nr_file_hugepages 0
      nr_file_pmdmapped 0
      nr_anon_transparent_hugepages 0
      nr_unstable  0
      nr_vmscan_write 51492
      nr_vmscan_immediate_reclaim 18
      nr_dirtied   3002641
      nr_written   2886401
      nr_kernel_misc_reclaimable 47191
      nr_unreclaimable_pages 206956
  /* 第(2)部分 */
  pages free     171227 //zone->vm_stat[NR_FREE_PAGES]
        min      32363  //zone->_watermark[WMARK_MIN] + zone->watermark_boost 单位: pages
        low      46813  //zone->_watermark[WMARK_LOW] + zone->watermark_boost
        high     47742  //zone->_watermark[WMARK_HIGH] + zone->watermark_boost
        spanned  8164351 //zone->spanned_pages
        present  3556807 //zone->present_pages
        managed  3463695 //zone->managed_pages
        protection: (0, 0) //zone->lowmem_reserve[0], zone->lowmem_reserve[1]
/* 第(3)部分, 打印的是 zone->vm_stat[item] 的值 */
      nr_free_pages 171227
      nr_zone_inactive_anon 152477
      nr_zone_active_anon 749181
      nr_zone_inactive_file 1028670
      nr_zone_active_file 143843
      nr_zone_unevictable 826
      nr_zone_write_pending 73
      nr_mlock     826
      nr_page_table_pages 28872
      nr_kernel_stack 62736
      nr_shadow_call_stack_bytes 16072704
      nr_bounce    0
      nr_zspages   7759
      nr_free_cma  1
/* 第(4)部分, 打印每cpu成员 zone->pageset 中部分成员的值 */
  pagesets
    cpu: 0                //cpu id
              count: 131  //zone->pageset->pcp.count
              high:  378  //zone->pageset->pcp.high
              batch: 63   //zone->pageset->pcp.batch
  vm stats threshold: 64  //zone->pageset->stat_threshold
    cpu: 1
              count: 46
              high:  378
              batch: 63
  vm stats threshold: 64
    cpu: 2
              count: 10
              high:  378
              batch: 63
  vm stats threshold: 64
    cpu: 3
              count: 102
              high:  378
              batch: 63
  vm stats threshold: 64
    cpu: 4
              count: 129
              high:  378
              batch: 63
  vm stats threshold: 64
    cpu: 5
              count: 150
              high:  378
              batch: 63
  vm stats threshold: 64
    cpu: 6
              count: 320
              high:  378
              batch: 63
  vm stats threshold: 64
    cpu: 7
              count: 33
              high:  378
              batch: 63
  vm stats threshold: 64
/* 第(5)部分 */
  node_unreclaimable:  0       //pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES(16) 的比较结果
  start_pfn:           716033  //zone->zone_start_pfn
/* 第(6)部分, 打印另一个zone的信息 */
Node 0, zone  Movable          //Movable内存区
  pages free     0
        min      0
        low      0
        high     0
        spanned  0
        present  0
        managed  0
        protection: (0, 0) //往下没有打印了，说明Movable zone->present_pages为0，即此zone没有物理内存

部分成员介绍：

pages free: 打印的是 zone->vm_stat[NR_FREE_PAGES]，表示这个内存管理区中空闲页面的数量。
min: 打印的是 zone->_watermark[WMARK_MIN] + zone->watermark_boost，表示这个内存管理区中处于最低警戒水位的页面的数量。详见 __setup_per_zone_wmarks()
low: 打印的是 zone->_watermark[WMARK_LOW] + zone->watermark_boost，表示这个内存管理区中处于低水位的页面的数量。
high: 打印的是 zone->_watermark[WMARK_HIGH] + zone->watermark_boost，表示这个内存管理区中处于高水位的页面的数量。
spanned: 打印的是 zone->spanned_pages，表示这个管理区跨越的页面数量，包含空洞。
present: 打印的是 zone->present_pages，表示这个管理区中实际页面的数量。
managed: 打印的是 zone->managed_pages，表示这个管理区中被伙伴系统管理的页面数量。
protection: 打印的是(zone->lowmem_reserve[0], zone->lowmem_reserve[1]), 表示这个管理区预留的内存的数量。

start_pfn: 打印的是 zone->zone_start_pfn, 表示此zone的起始页帧号。

二、打印位置

void __init init_mm_internals(void) //vmstat.c
    proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op);
}

static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, struct zone *zone) //vmstat.c
{
    int i;
    seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
    /* 找到第一个存在物理页面的zone */
    if (is_zone_first_populated(pgdat, zone)) {
        /* 打印第(1)部分 */
        seq_printf(m, "\n  per-node stats");
        /* 打印的是全局数组变量 vm_node_stat[i] 的值 */
        for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { //NR_VM_NUMA_STAT_ITEMS 是0
            seq_printf(m, "\n      %-12s %lu", vmstat_text[i + NR_VM_ZONE_STAT_ITEMS + NR_VM_NUMA_STAT_ITEMS], node_page_state(pgdat, i));
        }
    }
    /* 打印第(2)部分信息 */
    seq_printf(m,
           "\n  pages free     %lu"
           "\n        min      %lu"
           "\n        low      %lu"
           "\n        high     %lu"
           "\n        spanned  %lu"
           "\n        present  %lu"
           "\n        managed  %lu",
           zone_page_state(zone, NR_FREE_PAGES), //zone->vm_stat[NR_FREE_PAGES]
           min_wmark_pages(zone), //zone->_watermark[WMARK_MIN] + zone->watermark_boost
           low_wmark_pages(zone), //zone->_watermark[WMARK_LOW] + zone->watermark_boost
           high_wmark_pages(zone), //zone->_watermark[WMARK_HIGH] + zone->watermark_boost
           zone->spanned_pages,
           zone->present_pages,
           zone_managed_pages(zone)); //zone->managed_pages

    seq_printf(m, "\n        protection: (%ld", zone->lowmem_reserve[0]);
    for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) //2
        seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
    seq_putc(m, ')');

    /* If unpopulated, no other information is useful */
    if (!populated_zone(zone)) { //若 zone->present_pages 为0，则不打印了，Moveable zone将从则从这里退出
        seq_putc(m, '\n');
        return;
    }

    /* 打印第(3)部分信息，打印的是 zone->vm_stat[item] 的值 */
    for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
        seq_printf(m, "\n      %-12s %lu", vmstat_text[i], zone_page_state(zone, i));

    /* 打印第第(4)部分, 打印每cpu成员 zone->pageset 中部分成员的值 */
    seq_printf(m, "\n  pagesets");
    for_each_online_cpu(i) {
        struct per_cpu_pageset *pageset;

        pageset = per_cpu_ptr(zone->pageset, i);
        seq_printf(m,
               "\n    cpu: %i"
               "\n              count: %i"
               "\n              high:  %i"
               "\n              batch: %i",
               i,
               pageset->pcp.count,
               pageset->pcp.high,
               pageset->pcp.batch);
#ifdef CONFIG_SMP
        seq_printf(m, "\n  vm stats threshold: %d", pageset->stat_threshold);
#endif
    }
    /* 打印第(5)部分信息 */
    seq_printf(m,
           "\n  node_unreclaimable:  %u"
           "\n  start_pfn:           %lu",
           pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
           zone->zone_start_pfn);
    seq_putc(m, '\n');
}