src/sys_kernel_mm_ksm.c

   1 #include "common.h"
   2
   3 typedef struct ksm_name_value {
   4     char filename[FILENAME_MAX + 1];
   5     unsigned long long value;
   6 } KSM_NAME_VALUE;
   7
   8 #define PAGES_SHARED 0
   9 #define PAGES_SHARING 1
  10 #define PAGES_UNSHARED 2
  11 #define PAGES_VOLATILE 3
  12 #define PAGES_TO_SCAN 4
  13
  14 KSM_NAME_VALUE values[] = {
  15         [PAGES_SHARED] = { "/sys/kernel/mm/ksm/pages_shared", 0ULL },
  16         [PAGES_SHARING] = { "/sys/kernel/mm/ksm/pages_sharing", 0ULL },
  17         [PAGES_UNSHARED] = { "/sys/kernel/mm/ksm/pages_unshared", 0ULL },
  18         [PAGES_VOLATILE] = { "/sys/kernel/mm/ksm/pages_volatile", 0ULL },
  19         [PAGES_TO_SCAN] = { "/sys/kernel/mm/ksm/pages_to_scan", 0ULL },
  20 };
  21
  22 int do_sys_kernel_mm_ksm(int update_every, usec_t dt) {
  23     (void)dt;
  24     static procfile *ff_pages_shared = NULL, *ff_pages_sharing = NULL, *ff_pages_unshared = NULL, *ff_pages_volatile = NULL, *ff_pages_to_scan = NULL;
  25     static long page_size = -1;
  26
  27     if(page_size == -1)
  28         page_size = sysconf(_SC_PAGESIZE);
  29
  30     if(!ff_pages_shared) {
  31         snprintfz(values[PAGES_SHARED].filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/kernel/mm/ksm/pages_shared");
  32         snprintfz(values[PAGES_SHARED].filename, FILENAME_MAX, "%s", config_get("plugin:proc:/sys/kernel/mm/ksm", "/sys/kernel/mm/ksm/pages_shared", values[PAGES_SHARED].filename));
  33         ff_pages_shared = procfile_open(values[PAGES_SHARED].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  34     }
  35
  36     if(!ff_pages_sharing) {
  37         snprintfz(values[PAGES_SHARING].filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/kernel/mm/ksm/pages_sharing");
  38         snprintfz(values[PAGES_SHARING].filename, FILENAME_MAX, "%s", config_get("plugin:proc:/sys/kernel/mm/ksm", "/sys/kernel/mm/ksm/pages_sharing", values[PAGES_SHARING].filename));
  39         ff_pages_sharing = procfile_open(values[PAGES_SHARING].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  40     }
  41
  42     if(!ff_pages_unshared) {
  43         snprintfz(values[PAGES_UNSHARED].filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/kernel/mm/ksm/pages_unshared");
  44         snprintfz(values[PAGES_UNSHARED].filename, FILENAME_MAX, "%s", config_get("plugin:proc:/sys/kernel/mm/ksm", "/sys/kernel/mm/ksm/pages_unshared", values[PAGES_UNSHARED].filename));
  45         ff_pages_unshared = procfile_open(values[PAGES_UNSHARED].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  46     }
  47
  48     if(!ff_pages_volatile) {
  49         snprintfz(values[PAGES_VOLATILE].filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/kernel/mm/ksm/pages_volatile");
  50         snprintfz(values[PAGES_VOLATILE].filename, FILENAME_MAX, "%s", config_get("plugin:proc:/sys/kernel/mm/ksm", "/sys/kernel/mm/ksm/pages_volatile", values[PAGES_VOLATILE].filename));
  51         ff_pages_volatile = procfile_open(values[PAGES_VOLATILE].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  52     }
  53
  54     if(!ff_pages_to_scan) {
  55         snprintfz(values[PAGES_TO_SCAN].filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/kernel/mm/ksm/pages_to_scan");
  56         snprintfz(values[PAGES_TO_SCAN].filename, FILENAME_MAX, "%s", config_get("plugin:proc:/sys/kernel/mm/ksm", "/sys/kernel/mm/ksm/pages_to_scan", values[PAGES_TO_SCAN].filename));
  57         ff_pages_to_scan = procfile_open(values[PAGES_TO_SCAN].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  58     }
  59
  60     if(!ff_pages_shared || !ff_pages_sharing || !ff_pages_unshared || !ff_pages_volatile || !ff_pages_to_scan) return 1;
  61
  62     unsigned long long pages_shared = 0, pages_sharing = 0, pages_unshared = 0, pages_volatile = 0, pages_to_scan = 0, offered = 0, saved = 0;
  63
  64     ff_pages_shared = procfile_readall(ff_pages_shared);
  65     if(!ff_pages_shared) return 0; // we return 0, so that we will retry to open it next time
  66     pages_shared = str2ull(procfile_lineword(ff_pages_shared, 0, 0));
  67
  68     ff_pages_sharing = procfile_readall(ff_pages_sharing);
  69     if(!ff_pages_sharing) return 0; // we return 0, so that we will retry to open it next time
  70     pages_sharing = str2ull(procfile_lineword(ff_pages_sharing, 0, 0));
  71
  72     ff_pages_unshared = procfile_readall(ff_pages_unshared);
  73     if(!ff_pages_unshared) return 0; // we return 0, so that we will retry to open it next time
  74     pages_unshared = str2ull(procfile_lineword(ff_pages_unshared, 0, 0));
  75
  76     ff_pages_volatile = procfile_readall(ff_pages_volatile);
  77     if(!ff_pages_volatile) return 0; // we return 0, so that we will retry to open it next time
  78     pages_volatile = str2ull(procfile_lineword(ff_pages_volatile, 0, 0));
  79
  80     ff_pages_to_scan = procfile_readall(ff_pages_to_scan);
  81     if(!ff_pages_to_scan) return 0; // we return 0, so that we will retry to open it next time
  82     pages_to_scan = str2ull(procfile_lineword(ff_pages_to_scan, 0, 0));
  83
  84     offered = pages_sharing + pages_shared + pages_unshared + pages_volatile;
  85     saved = pages_sharing - pages_shared;
  86
  87     if(!offered || !pages_to_scan) return 0;
  88
  89     RRDSET *st;
  90
  91     // --------------------------------------------------------------------
  92
  93     st = rrdset_find_localhost("mem.ksm");
  94     if(!st) {
  95         st = rrdset_create_localhost("mem", "ksm", NULL, "ksm", NULL, "Kernel Same Page Merging", "MB", 5000
  96                                      , update_every, RRDSET_TYPE_AREA);
  97
  98         rrddim_add(st, "shared", NULL, 1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
  99         rrddim_add(st, "unshared", NULL, -1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
 100         rrddim_add(st, "sharing", NULL, 1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
 101         rrddim_add(st, "volatile", NULL, -1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
 102         rrddim_add(st, "to_scan", "to scan", -1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
 103     }
 104     else rrdset_next(st);
 105
 106     rrddim_set(st, "shared", pages_shared * page_size);
 107     rrddim_set(st, "unshared", pages_unshared * page_size);
 108     rrddim_set(st, "sharing", pages_sharing * page_size);
 109     rrddim_set(st, "volatile", pages_volatile * page_size);
 110     rrddim_set(st, "to_scan", pages_to_scan * page_size);
 111     rrdset_done(st);
 112
 113     st = rrdset_find_localhost("mem.ksm_savings");
 114     if(!st) {
 115         st = rrdset_create_localhost("mem", "ksm_savings", NULL, "ksm", NULL, "Kernel Same Page Merging Savings", "MB"
 116                                      , 5001, update_every, RRDSET_TYPE_AREA);
 117
 118         rrddim_add(st, "savings", NULL, -1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
 119         rrddim_add(st, "offered", NULL, 1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
 120     }
 121     else rrdset_next(st);
 122
 123     rrddim_set(st, "savings", saved * page_size);
 124     rrddim_set(st, "offered", offered * page_size);
 125     rrdset_done(st);
 126
 127     st = rrdset_find_localhost("mem.ksm_ratios");
 128     if(!st) {
 129         st = rrdset_create_localhost("mem", "ksm_ratios", NULL, "ksm", NULL, "Kernel Same Page Merging Effectiveness"
 130                                      , "percentage", 5002, update_every, RRDSET_TYPE_LINE);
 131
 132         rrddim_add(st, "savings", NULL, 1, 10000, RRD_ALGORITHM_ABSOLUTE);
 133     }
 134     else rrdset_next(st);
 135
 136     rrddim_set(st, "savings", (saved * 1000000) / offered);
 137     rrdset_done(st);
 138
 139     return 0;
 140 }