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 <linux/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 struct appldata_mem_data { 34 u64 timestamp; 35 u32 sync_count_1; /* after VM collected the record data, */ 36 u32 sync_count_2; /* sync_count_1 and sync_count_2 should be the 37 same. If not, the record has been updated on 38 the Linux side while VM was collecting the 39 (possibly corrupt) data */ 40 41 u64 pgpgin; /* data read from disk */ 42 u64 pgpgout; /* data written to disk */ 43 u64 pswpin; /* pages swapped in */ 44 u64 pswpout; /* pages swapped out */ 45 46 u64 sharedram; /* sharedram is currently set to 0 */ 47 48 u64 totalram; /* total main memory size */ 49 u64 freeram; /* free main memory size */ 50 u64 totalhigh; /* total high memory size */ 51 u64 freehigh; /* free high memory size */ 52 53 u64 bufferram; /* memory reserved for buffers, free cache */ 54 u64 cached; /* size of (used) cache, w/o buffers */ 55 u64 totalswap; /* total swap space size */ 56 u64 freeswap; /* free swap space */ 57 58 // New in 2.6 --> 59 u64 pgalloc; /* page allocations */ 60 u64 pgfault; /* page faults (major+minor) */ 61 u64 pgmajfault; /* page faults (major only) */ 62 // <-- New in 2.6 63 64 } __packed; 65 66 67 /* 68 * appldata_get_mem_data() 69 * 70 * gather memory data 71 */ 72 static void appldata_get_mem_data(void *data) 73 { 74 /* 75 * don't put large structures on the stack, we are 76 * serialized through the appldata_ops_mutex and can use static 77 */ 78 static struct sysinfo val; 79 unsigned long ev[NR_VM_EVENT_ITEMS]; 80 struct appldata_mem_data *mem_data; 81 82 mem_data = data; 83 mem_data->sync_count_1++; 84 85 all_vm_events(ev); 86 mem_data->pgpgin = ev[PGPGIN] >> 1; 87 mem_data->pgpgout = ev[PGPGOUT] >> 1; 88 mem_data->pswpin = ev[PSWPIN]; 89 mem_data->pswpout = ev[PSWPOUT]; 90 mem_data->pgalloc = ev[PGALLOC_NORMAL]; 91 mem_data->pgalloc += ev[PGALLOC_DMA]; 92 mem_data->pgfault = ev[PGFAULT]; 93 mem_data->pgmajfault = ev[PGMAJFAULT]; 94 95 si_meminfo(&val); 96 mem_data->sharedram = val.sharedram; 97 mem_data->totalram = P2K(val.totalram); 98 mem_data->freeram = P2K(val.freeram); 99 mem_data->totalhigh = P2K(val.totalhigh); 100 mem_data->freehigh = P2K(val.freehigh); 101 mem_data->bufferram = P2K(val.bufferram); 102 mem_data->cached = P2K(global_node_page_state(NR_FILE_PAGES) 103 - val.bufferram); 104 105 si_swapinfo(&val); 106 mem_data->totalswap = P2K(val.totalswap); 107 mem_data->freeswap = P2K(val.freeswap); 108 109 mem_data->timestamp = get_tod_clock(); 110 mem_data->sync_count_2++; 111 } 112 113 114 static struct appldata_ops ops = { 115 .name = "mem", 116 .record_nr = APPLDATA_RECORD_MEM_ID, 117 .size = sizeof(struct appldata_mem_data), 118 .callback = &appldata_get_mem_data, 119 .owner = THIS_MODULE, 120 .mod_lvl = {0xF0, 0xF0}, /* EBCDIC "00" */ 121 }; 122 123 124 /* 125 * appldata_mem_init() 126 * 127 * init_data, register ops 128 */ 129 static int __init appldata_mem_init(void) 130 { 131 int ret; 132 133 ops.data = kzalloc(sizeof(struct appldata_mem_data), GFP_KERNEL); 134 if (!ops.data) 135 return -ENOMEM; 136 137 ret = appldata_register_ops(&ops); 138 if (ret) 139 kfree(ops.data); 140 141 return ret; 142 } 143 144 /* 145 * appldata_mem_exit() 146 * 147 * unregister ops 148 */ 149 static void __exit appldata_mem_exit(void) 150 { 151 appldata_unregister_ops(&ops); 152 kfree(ops.data); 153 } 154 155 156 module_init(appldata_mem_init); 157 module_exit(appldata_mem_exit); 158 159 MODULE_LICENSE("GPL"); 160 MODULE_AUTHOR("Gerald Schaefer"); 161 MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics"); 162