src/sys_kernel_mm_ksm.c

   1 #ifdef HAVE_CONFIG_H
   2 #include <config.h>
   3 #endif
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "common.h"
   9 #include "log.h"
  10 #include "appconfig.h"
  11 #include "procfile.h"
  12 #include "rrd.h"
  13 #include "plugin_proc.h"
  14
  15 typedef struct name_value {
  16         char filename[FILENAME_MAX + 1];
  17         unsigned long long value;
  18 } NAME_VALUE;
  19
  20 #define PAGES_SHARED 0
  21 #define PAGES_SHARING 1
  22 #define PAGES_UNSHARED 2
  23 #define PAGES_VOLATILE 3
  24 #define PAGES_TO_SCAN 4
  25
  26 NAME_VALUE values[] = {
  27                 [PAGES_SHARED] = { "/sys/kernel/mm/ksm/pages_shared", 0ULL },
  28                 [PAGES_SHARING] = { "/sys/kernel/mm/ksm/pages_sharing", 0ULL },
  29                 [PAGES_UNSHARED] = { "/sys/kernel/mm/ksm/pages_unshared", 0ULL },
  30                 [PAGES_VOLATILE] = { "/sys/kernel/mm/ksm/pages_volatile", 0ULL },
  31                 [PAGES_TO_SCAN] = { "/sys/kernel/mm/ksm/pages_to_scan", 0ULL },
  32 };
  33
  34 int do_sys_kernel_mm_ksm(int update_every, unsigned long long dt) {
  35         static procfile *ff_pages_shared = NULL, *ff_pages_sharing = NULL, *ff_pages_unshared = NULL, *ff_pages_volatile = NULL, *ff_pages_to_scan = NULL;
  36         static long page_size = -1;
  37
  38         if(dt) {};
  39
  40         if(page_size == -1)
  41                 page_size = sysconf(_SC_PAGESIZE);
  42
  43         if(!ff_pages_shared) {
  44                 snprintf(values[PAGES_SHARED].filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/kernel/mm/ksm/pages_shared");
  45                 snprintf(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));
  46                 ff_pages_shared = procfile_open(values[PAGES_SHARED].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  47         }
  48
  49         if(!ff_pages_sharing) {
  50                 snprintf(values[PAGES_SHARING].filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/kernel/mm/ksm/pages_sharing");
  51                 snprintf(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));
  52                 ff_pages_sharing = procfile_open(values[PAGES_SHARING].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  53         }
  54
  55         if(!ff_pages_unshared) {
  56                 snprintf(values[PAGES_UNSHARED].filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/kernel/mm/ksm/pages_unshared");
  57                 snprintf(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));
  58                 ff_pages_unshared = procfile_open(values[PAGES_UNSHARED].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  59         }
  60
  61         if(!ff_pages_volatile) {
  62                 snprintf(values[PAGES_VOLATILE].filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/kernel/mm/ksm/pages_volatile");
  63                 snprintf(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));
  64                 ff_pages_volatile = procfile_open(values[PAGES_VOLATILE].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  65         }
  66
  67         if(!ff_pages_to_scan) {
  68                 snprintf(values[PAGES_TO_SCAN].filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/kernel/mm/ksm/pages_to_scan");
  69                 snprintf(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));
  70                 ff_pages_to_scan = procfile_open(values[PAGES_TO_SCAN].filename, " \t:", PROCFILE_FLAG_DEFAULT);
  71         }
  72
  73         if(!ff_pages_shared || !ff_pages_sharing || !ff_pages_unshared || !ff_pages_volatile || !ff_pages_to_scan) return 1;
  74
  75         unsigned long long pages_shared = 0, pages_sharing = 0, pages_unshared = 0, pages_volatile = 0, pages_to_scan = 0, offered = 0, saved = 0;
  76
  77         ff_pages_shared = procfile_readall(ff_pages_shared);
  78         if(!ff_pages_shared) return 0; // we return 0, so that we will retry to open it next time
  79         pages_shared = strtoull(procfile_lineword(ff_pages_shared, 0, 0), NULL, 10);
  80
  81         ff_pages_sharing = procfile_readall(ff_pages_sharing);
  82         if(!ff_pages_sharing) return 0; // we return 0, so that we will retry to open it next time
  83         pages_sharing = strtoull(procfile_lineword(ff_pages_sharing, 0, 0), NULL, 10);
  84
  85         ff_pages_unshared = procfile_readall(ff_pages_unshared);
  86         if(!ff_pages_unshared) return 0; // we return 0, so that we will retry to open it next time
  87         pages_unshared = strtoull(procfile_lineword(ff_pages_unshared, 0, 0), NULL, 10);
  88
  89         ff_pages_volatile = procfile_readall(ff_pages_volatile);
  90         if(!ff_pages_volatile) return 0; // we return 0, so that we will retry to open it next time
  91         pages_volatile = strtoull(procfile_lineword(ff_pages_volatile, 0, 0), NULL, 10);
  92
  93         ff_pages_to_scan = procfile_readall(ff_pages_to_scan);
  94         if(!ff_pages_to_scan) return 0; // we return 0, so that we will retry to open it next time
  95         pages_to_scan = strtoull(procfile_lineword(ff_pages_to_scan, 0, 0), NULL, 10);
  96
  97         offered = pages_sharing + pages_unshared + pages_volatile;
  98         saved = pages_sharing - pages_shared;
  99
 100         if(!offered || !pages_to_scan) return 0;
 101
 102         RRDSET *st;
 103
 104         // --------------------------------------------------------------------
 105
 106         st = rrdset_find("mem.ksm");
 107         if(!st) {
 108                 st = rrdset_create("mem", "ksm", NULL, "ksm", NULL, "Kernel Same Page Merging", "MB", 5000, update_every, RRDSET_TYPE_AREA);
 109
 110                 rrddim_add(st, "shared", NULL, 1, 1024 * 1024, RRDDIM_ABSOLUTE);
 111                 rrddim_add(st, "unshared", NULL, -1, 1024 * 1024, RRDDIM_ABSOLUTE);
 112                 rrddim_add(st, "sharing", NULL, 1, 1024 * 1024, RRDDIM_ABSOLUTE);
 113                 rrddim_add(st, "volatile", NULL, -1, 1024 * 1024, RRDDIM_ABSOLUTE);
 114                 rrddim_add(st, "to_scan", "to scan", -1, 1024 * 1024, RRDDIM_ABSOLUTE);
 115         }
 116         else rrdset_next(st);
 117
 118         rrddim_set(st, "shared", pages_shared * page_size);
 119         rrddim_set(st, "unshared", pages_unshared * page_size);
 120         rrddim_set(st, "sharing", pages_sharing * page_size);
 121         rrddim_set(st, "volatile", pages_volatile * page_size);
 122         rrddim_set(st, "to_scan", pages_to_scan * page_size);
 123         rrdset_done(st);
 124
 125         st = rrdset_find("mem.ksm_savings");
 126         if(!st) {
 127                 st = rrdset_create("mem", "ksm_savings", NULL, "ksm", NULL, "Kernel Same Page Merging Savings", "MB", 5001, update_every, RRDSET_TYPE_AREA);
 128
 129                 rrddim_add(st, "savings", NULL, -1, 1024 * 1024, RRDDIM_ABSOLUTE);
 130                 rrddim_add(st, "offered", NULL, 1, 1024 * 1024, RRDDIM_ABSOLUTE);
 131         }
 132         else rrdset_next(st);
 133
 134         rrddim_set(st, "savings", saved * page_size);
 135         rrddim_set(st, "offered", offered * page_size);
 136         rrdset_done(st);
 137
 138         st = rrdset_find("mem.ksm_ratios");
 139         if(!st) {
 140                 st = rrdset_create("mem", "ksm_ratios", NULL, "ksm", NULL, "Kernel Same Page Merging Effectiveness", "percentage", 5002, update_every, RRDSET_TYPE_LINE);
 141
 142                 rrddim_add(st, "savings", NULL, 1, 10000, RRDDIM_ABSOLUTE);
 143         }
 144         else rrdset_next(st);
 145
 146         rrddim_set(st, "savings", (saved * 1000000) / offered);
 147         rrdset_done(st);
 148
 149         return 0;
 150 }