arch/s390/appldata/appldata_mem.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Data gathering module for Linux-VM Monitor Stream, Stage 1.
   4  * Collects data related to memory management.
   5  *
   6  * Copyright IBM Corp. 2003, 2006
   7  *
   8  * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel_stat.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/swap.h>
  17 #include <linux/slab.h>
  18 #include <asm/io.h>
  19
  20 #include "appldata.h"
  21
  22
  23 #define P2K(x) ((x) << (PAGE_SHIFT - 10))       /* Converts #Pages to KB */
  24
  25 /*
  26  * Memory data
  27  *
  28  * This is accessed as binary data by z/VM. If changes to it can't be avoided,
  29  * the structure version (product ID, see appldata_base.c) needs to be changed
  30  * as well and all documentation and z/VM applications using it must be
  31  * updated.
  32  *
  33  * The record layout is documented in the Linux for zSeries Device Drivers
  34  * book:
  35  * http://oss.software.ibm.com/developerworks/opensource/linux390/index.shtml
  36  */
  37 struct appldata_mem_data {
  38         u64 timestamp;
  39         u32 sync_count_1;       /* after VM collected the record data, */
  40         u32 sync_count_2;       /* sync_count_1 and sync_count_2 should be the
  41                                    same. If not, the record has been updated on
  42                                    the Linux side while VM was collecting the
  43                                    (possibly corrupt) data */
  44
  45         u64 pgpgin;             /* data read from disk  */
  46         u64 pgpgout;            /* data written to disk */
  47         u64 pswpin;             /* pages swapped in  */
  48         u64 pswpout;            /* pages swapped out */
  49
  50         u64 sharedram;          /* sharedram is currently set to 0 */
  51
  52         u64 totalram;           /* total main memory size */
  53         u64 freeram;            /* free main memory size  */
  54         u64 totalhigh;          /* total high memory size */
  55         u64 freehigh;           /* free high memory size  */
  56
  57         u64 bufferram;          /* memory reserved for buffers, free cache */
  58         u64 cached;             /* size of (used) cache, w/o buffers */
  59         u64 totalswap;          /* total swap space size */
  60         u64 freeswap;           /* free swap space */
  61
  62 // New in 2.6 -->
  63         u64 pgalloc;            /* page allocations */
  64         u64 pgfault;            /* page faults (major+minor) */
  65         u64 pgmajfault;         /* page faults (major only) */
  66 // <-- New in 2.6
  67
  68 } __packed;
  69
  70
  71 /*
  72  * appldata_get_mem_data()
  73  *
  74  * gather memory data
  75  */
  76 static void appldata_get_mem_data(void *data)
  77 {
  78         /*
  79          * don't put large structures on the stack, we are
  80          * serialized through the appldata_ops_mutex and can use static
  81          */
  82         static struct sysinfo val;
  83         unsigned long ev[NR_VM_EVENT_ITEMS];
  84         struct appldata_mem_data *mem_data;
  85
  86         mem_data = data;
  87         mem_data->sync_count_1++;
  88
  89         all_vm_events(ev);
  90         mem_data->pgpgin     = ev[PGPGIN] >> 1;
  91         mem_data->pgpgout    = ev[PGPGOUT] >> 1;
  92         mem_data->pswpin     = ev[PSWPIN];
  93         mem_data->pswpout    = ev[PSWPOUT];
  94         mem_data->pgalloc    = ev[PGALLOC_NORMAL];
  95         mem_data->pgalloc    += ev[PGALLOC_DMA];
  96         mem_data->pgfault    = ev[PGFAULT];
  97         mem_data->pgmajfault = ev[PGMAJFAULT];
  98
  99         si_meminfo(&val);
 100         mem_data->sharedram = val.sharedram;
 101         mem_data->totalram  = P2K(val.totalram);
 102         mem_data->freeram   = P2K(val.freeram);
 103         mem_data->totalhigh = P2K(val.totalhigh);
 104         mem_data->freehigh  = P2K(val.freehigh);
 105         mem_data->bufferram = P2K(val.bufferram);
 106         mem_data->cached    = P2K(global_node_page_state(NR_FILE_PAGES)
 107                                 - val.bufferram);
 108
 109         si_swapinfo(&val);
 110         mem_data->totalswap = P2K(val.totalswap);
 111         mem_data->freeswap  = P2K(val.freeswap);
 112
 113         mem_data->timestamp = get_tod_clock();
 114         mem_data->sync_count_2++;
 115 }
 116
 117
 118 static struct appldata_ops ops = {
 119         .name      = "mem",
 120         .record_nr = APPLDATA_RECORD_MEM_ID,
 121         .size      = sizeof(struct appldata_mem_data),
 122         .callback  = &appldata_get_mem_data,
 123         .owner     = THIS_MODULE,
 124         .mod_lvl   = {0xF0, 0xF0},              /* EBCDIC "00" */
 125 };
 126
 127
 128 /*
 129  * appldata_mem_init()
 130  *
 131  * init_data, register ops
 132  */
 133 static int __init appldata_mem_init(void)
 134 {
 135         int ret;
 136
 137         ops.data = kzalloc(sizeof(struct appldata_mem_data), GFP_KERNEL);
 138         if (!ops.data)
 139                 return -ENOMEM;
 140
 141         ret = appldata_register_ops(&ops);
 142         if (ret)
 143                 kfree(ops.data);
 144
 145         return ret;
 146 }
 147
 148 /*
 149  * appldata_mem_exit()
 150  *
 151  * unregister ops
 152  */
 153 static void __exit appldata_mem_exit(void)
 154 {
 155         appldata_unregister_ops(&ops);
 156         kfree(ops.data);
 157 }
 158
 159
 160 module_init(appldata_mem_init);
 161 module_exit(appldata_mem_exit);
 162
 163 MODULE_LICENSE("GPL");
 164 MODULE_AUTHOR("Gerald Schaefer");
 165 MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics");