src/collectors/proc.plugin/ipc.c
// SPDX-License-Identifier: GPL-3.0-or-later
#include "plugin_proc.h"
#include <sys/sem.h>
#include <sys/msg.h>
#include <sys/shm.h>
#ifndef SEMVMX
#define SEMVMX 32767 /* <= 32767 semaphore maximum value */
#endif
/* Some versions of libc only define IPC_INFO when __USE_GNU is defined. */
#ifndef IPC_INFO
#define IPC_INFO 3
#endif
struct ipc_limits {
uint64_t shmmni; /* max number of segments */
uint64_t shmmax; /* max segment size */
uint64_t shmall; /* max total shared memory */
uint64_t shmmin; /* min segment size */
int semmni; /* max number of arrays */
int semmsl; /* max semaphores per array */
int semmns; /* max semaphores system wide */
int semopm; /* max ops per semop call */
unsigned int semvmx; /* semaphore max value (constant) */
int msgmni; /* max queues system wide */
size_t msgmax; /* max size of message */
int msgmnb; /* default max size of queue */
};
struct ipc_status {
int semusz; /* current number of arrays */
int semaem; /* current semaphores system wide */
};
/*
* The last arg of semctl is a union semun, but where is it defined? X/OPEN
* tells us to define it ourselves, but until recently Linux include files
* would also define it.
*/
#ifndef HAVE_UNION_SEMUN
/* according to X/OPEN we have to define it ourselves */
union semun {
int val;
struct semid_ds *buf;
unsigned short int *array;
struct seminfo *__buf;
};
#endif
struct message_queue {
unsigned long long id;
int found;
RRDDIM *rd_messages;
RRDDIM *rd_bytes;
unsigned long long messages;
unsigned long long bytes;
struct message_queue * next;
};
struct shm_stats {
unsigned long long segments;
unsigned long long bytes;
};
static inline int ipc_sem_get_limits(struct ipc_limits *lim) {
static procfile *ff = NULL;
static int error_shown = 0;
static char filename[FILENAME_MAX + 1] = "";
if(unlikely(!filename[0]))
snprintfz(filename, FILENAME_MAX, "%s/proc/sys/kernel/sem", netdata_configured_host_prefix);
if(unlikely(!ff)) {
ff = procfile_open(filename, NULL, PROCFILE_FLAG_DEFAULT);
if(unlikely(!ff)) {
if(unlikely(!error_shown)) {
collector_error("IPC: Cannot open file '%s'.", filename);
error_shown = 1;
}
goto ipc;
}
}
ff = procfile_readall(ff);
if(unlikely(!ff)) {
if(unlikely(!error_shown)) {
collector_error("IPC: Cannot read file '%s'.", filename);
error_shown = 1;
}
goto ipc;
}
if(procfile_lines(ff) >= 1 && procfile_linewords(ff, 0) >= 4) {
lim->semvmx = SEMVMX;
lim->semmsl = str2i(procfile_lineword(ff, 0, 0));
lim->semmns = str2i(procfile_lineword(ff, 0, 1));
lim->semopm = str2i(procfile_lineword(ff, 0, 2));
lim->semmni = str2i(procfile_lineword(ff, 0, 3));
return 0;
}
else {
if(unlikely(!error_shown)) {
collector_error("IPC: Invalid content in file '%s'.", filename);
error_shown = 1;
}
goto ipc;
}
ipc:
// cannot do it from the file
// query IPC
{
struct seminfo seminfo = {.semmni = 0};
union semun arg = {.array = (ushort *) &seminfo};
if(unlikely(semctl(0, 0, IPC_INFO, arg) < 0)) {
collector_error("IPC: Failed to read '%s' and request IPC_INFO with semctl().", filename);
goto error;
}
lim->semvmx = SEMVMX;
lim->semmni = seminfo.semmni;
lim->semmsl = seminfo.semmsl;
lim->semmns = seminfo.semmns;
lim->semopm = seminfo.semopm;
return 0;
}
error:
lim->semvmx = 0;
lim->semmni = 0;
lim->semmsl = 0;
lim->semmns = 0;
lim->semopm = 0;
return -1;
}
/*
printf ("------ Semaphore Limits --------\n");
printf ("max number of arrays = %d\n", limits.semmni);
printf ("max semaphores per array = %d\n", limits.semmsl);
printf ("max semaphores system wide = %d\n", limits.semmns);
printf ("max ops per semop call = %d\n", limits.semopm);
printf ("semaphore max value = %u\n", limits.semvmx);
printf ("------ Semaphore Status --------\n");
printf ("used arrays = %d\n", status.semusz);
printf ("allocated semaphores = %d\n", status.semaem);
*/
static inline int ipc_sem_get_status(struct ipc_status *st) {
struct seminfo seminfo;
union semun arg;
arg.array = (ushort *) (void *) &seminfo;
if(unlikely(semctl (0, 0, SEM_INFO, arg) < 0)) {
/* kernel not configured for semaphores */
static int error_shown = 0;
if(unlikely(!error_shown)) {
collector_error("IPC: kernel is not configured for semaphores");
error_shown = 1;
}
st->semusz = 0;
st->semaem = 0;
return -1;
}
st->semusz = seminfo.semusz;
st->semaem = seminfo.semaem;
return 0;
}
int ipc_msq_get_info(char *msg_filename, struct message_queue **message_queue_root) {
static procfile *ff;
struct message_queue *msq;
if(unlikely(!ff)) {
ff = procfile_open(msg_filename, " \t:", PROCFILE_FLAG_DEFAULT);
if(unlikely(!ff)) return 1;
}
ff = procfile_readall(ff);
if(unlikely(!ff)) return 1;
size_t lines = procfile_lines(ff);
size_t words = 0;
if(unlikely(lines < 2)) {
collector_error("Cannot read %s. Expected 2 or more lines, read %zu.", procfile_filename(ff), lines);
return 1;
}
// loop through all lines except the first and the last ones
size_t l;
for(l = 1; l < lines - 1; l++) {
words = procfile_linewords(ff, l);
if(unlikely(words < 2)) continue;
if(unlikely(words < 14)) {
collector_error("Cannot read %s line. Expected 14 params, read %zu.", procfile_filename(ff), words);
continue;
}
// find the id in the linked list or create a new structure
int found = 0;
unsigned long long id = str2ull(procfile_lineword(ff, l, 1), NULL);
for(msq = *message_queue_root; msq ; msq = msq->next) {
if(unlikely(id == msq->id)) {
found = 1;
break;
}
}
if(unlikely(!found)) {
msq = callocz(1, sizeof(struct message_queue));
msq->next = *message_queue_root;
*message_queue_root = msq;
msq->id = id;
}
msq->messages = str2ull(procfile_lineword(ff, l, 4), NULL);
msq->bytes = str2ull(procfile_lineword(ff, l, 3), NULL);
msq->found = 1;
}
return 0;
}
int ipc_shm_get_info(char *shm_filename, struct shm_stats *shm) {
static procfile *ff;
if(unlikely(!ff)) {
ff = procfile_open(shm_filename, " \t:", PROCFILE_FLAG_DEFAULT);
if(unlikely(!ff)) return 1;
}
ff = procfile_readall(ff);
if(unlikely(!ff)) return 1;
size_t lines = procfile_lines(ff);
size_t words = 0;
if(unlikely(lines < 2)) {
collector_error("Cannot read %s. Expected 2 or more lines, read %zu.", procfile_filename(ff), lines);
return 1;
}
shm->segments = 0;
shm->bytes = 0;
// loop through all lines except the first and the last ones
size_t l;
for(l = 1; l < lines - 1; l++) {
words = procfile_linewords(ff, l);
if(unlikely(words < 2)) continue;
if(unlikely(words < 16)) {
collector_error("Cannot read %s line. Expected 16 params, read %zu.", procfile_filename(ff), words);
continue;
}
shm->segments++;
shm->bytes += str2ull(procfile_lineword(ff, l, 3), NULL);
}
return 0;
}
int do_ipc(int update_every, usec_t dt) {
(void)dt;
static int do_sem = -1, do_msg = -1, do_shm = -1;
static int read_limits_next = -1;
static struct ipc_limits limits;
static struct ipc_status status;
static const RRDVAR_ACQUIRED *arrays_max = NULL, *semaphores_max = NULL;
static RRDSET *st_semaphores = NULL, *st_arrays = NULL;
static RRDDIM *rd_semaphores = NULL, *rd_arrays = NULL;
static char *msg_filename = NULL;
static struct message_queue *message_queue_root = NULL;
static long long dimensions_limit;
static char *shm_filename = NULL;
if(unlikely(do_sem == -1)) {
do_msg = config_get_boolean("plugin:proc:ipc", "message queues", CONFIG_BOOLEAN_YES);
do_sem = config_get_boolean("plugin:proc:ipc", "semaphore totals", CONFIG_BOOLEAN_YES);
do_shm = config_get_boolean("plugin:proc:ipc", "shared memory totals", CONFIG_BOOLEAN_YES);
char filename[FILENAME_MAX + 1];
snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/proc/sysvipc/msg");
msg_filename = config_get("plugin:proc:ipc", "msg filename to monitor", filename);
snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/proc/sysvipc/shm");
shm_filename = config_get("plugin:proc:ipc", "shm filename to monitor", filename);
dimensions_limit = config_get_number("plugin:proc:ipc", "max dimensions in memory allowed", 50);
// make sure it works
if(ipc_sem_get_limits(&limits) == -1) {
collector_error("unable to fetch semaphore limits");
do_sem = CONFIG_BOOLEAN_NO;
}
else if(ipc_sem_get_status(&status) == -1) {
collector_error("unable to fetch semaphore statistics");
do_sem = CONFIG_BOOLEAN_NO;
}
else {
// create the charts
if(unlikely(!st_semaphores)) {
st_semaphores = rrdset_create_localhost(
"system"
, "ipc_semaphores"
, NULL
, "ipc semaphores"
, NULL
, "IPC Semaphores"
, "semaphores"
, PLUGIN_PROC_NAME
, "ipc"
, NETDATA_CHART_PRIO_SYSTEM_IPC_SEMAPHORES
, localhost->rrd_update_every
, RRDSET_TYPE_AREA
);
rd_semaphores = rrddim_add(st_semaphores, "semaphores", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
}
if(unlikely(!st_arrays)) {
st_arrays = rrdset_create_localhost(
"system"
, "ipc_semaphore_arrays"
, NULL
, "ipc semaphores"
, NULL
, "IPC Semaphore Arrays"
, "arrays"
, PLUGIN_PROC_NAME
, "ipc"
, NETDATA_CHART_PRIO_SYSTEM_IPC_SEM_ARRAYS
, localhost->rrd_update_every
, RRDSET_TYPE_AREA
);
rd_arrays = rrddim_add(st_arrays, "arrays", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
}
// variables
semaphores_max = rrdvar_host_variable_add_and_acquire(localhost, "ipc_semaphores_max");
arrays_max = rrdvar_host_variable_add_and_acquire(localhost, "ipc_semaphores_arrays_max");
}
struct stat stbuf;
if (stat(msg_filename, &stbuf)) {
do_msg = CONFIG_BOOLEAN_NO;
}
if(unlikely(do_sem == CONFIG_BOOLEAN_NO && do_msg == CONFIG_BOOLEAN_NO)) {
collector_error("ipc module disabled");
return 1;
}
}
if(likely(do_sem != CONFIG_BOOLEAN_NO)) {
if(unlikely(read_limits_next < 0)) {
if(unlikely(ipc_sem_get_limits(&limits) == -1)) {
collector_error("Unable to fetch semaphore limits.");
}
else {
if(semaphores_max)
rrdvar_host_variable_set(localhost, semaphores_max, limits.semmns);
if(arrays_max)
rrdvar_host_variable_set(localhost, arrays_max, limits.semmni);
st_arrays->red = limits.semmni;
st_semaphores->red = limits.semmns;
read_limits_next = 60 / update_every;
}
}
else
read_limits_next--;
if(unlikely(ipc_sem_get_status(&status) == -1)) {
collector_error("Unable to get semaphore statistics");
return 0;
}
rrddim_set_by_pointer(st_semaphores, rd_semaphores, status.semaem);
rrdset_done(st_semaphores);
rrddim_set_by_pointer(st_arrays, rd_arrays, status.semusz);
rrdset_done(st_arrays);
}
if(likely(do_msg != CONFIG_BOOLEAN_NO)) {
static RRDSET *st_msq_messages = NULL, *st_msq_bytes = NULL;
int ret = ipc_msq_get_info(msg_filename, &message_queue_root);
if(!ret && message_queue_root) {
if(unlikely(!st_msq_messages))
st_msq_messages = rrdset_create_localhost(
"system"
, "message_queue_messages"
, NULL
, "ipc message queues"
, NULL
, "IPC Message Queue Number of Messages"
, "messages"
, PLUGIN_PROC_NAME
, "ipc"
, NETDATA_CHART_PRIO_SYSTEM_IPC_MSQ_MESSAGES
, update_every
, RRDSET_TYPE_STACKED
);
if(unlikely(!st_msq_bytes))
st_msq_bytes = rrdset_create_localhost(
"system"
, "message_queue_bytes"
, NULL
, "ipc message queues"
, NULL
, "IPC Message Queue Used Bytes"
, "bytes"
, PLUGIN_PROC_NAME
, "ipc"
, NETDATA_CHART_PRIO_SYSTEM_IPC_MSQ_SIZE
, update_every
, RRDSET_TYPE_STACKED
);
struct message_queue *msq = message_queue_root, *msq_prev = NULL;
while(likely(msq)){
if(likely(msq->found)) {
if(unlikely(!msq->rd_messages || !msq->rd_bytes)) {
char id[RRD_ID_LENGTH_MAX + 1];
snprintfz(id, RRD_ID_LENGTH_MAX, "%llu", msq->id);
if(likely(!msq->rd_messages)) msq->rd_messages = rrddim_add(st_msq_messages, id, NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
if(likely(!msq->rd_bytes)) msq->rd_bytes = rrddim_add(st_msq_bytes, id, NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
}
rrddim_set_by_pointer(st_msq_messages, msq->rd_messages, msq->messages);
rrddim_set_by_pointer(st_msq_bytes, msq->rd_bytes, msq->bytes);
msq->found = 0;
}
else {
rrddim_is_obsolete___safe_from_collector_thread(st_msq_messages, msq->rd_messages);
rrddim_is_obsolete___safe_from_collector_thread(st_msq_bytes, msq->rd_bytes);
// remove message queue from the linked list
if(!msq_prev)
message_queue_root = msq->next;
else
msq_prev->next = msq->next;
freez(msq);
msq = NULL;
}
if(likely(msq)) {
msq_prev = msq;
msq = msq->next;
}
else if(!msq_prev)
msq = message_queue_root;
else
msq = msq_prev->next;
}
rrdset_done(st_msq_messages);
rrdset_done(st_msq_bytes);
long long dimensions_num = rrdset_number_of_dimensions(st_msq_messages);
if(unlikely(dimensions_num > dimensions_limit)) {
collector_info("Message queue statistics has been disabled");
collector_info("There are %lld dimensions in memory but limit was set to %lld", dimensions_num, dimensions_limit);
rrdset_is_obsolete___safe_from_collector_thread(st_msq_messages);
rrdset_is_obsolete___safe_from_collector_thread(st_msq_bytes);
st_msq_messages = NULL;
st_msq_bytes = NULL;
do_msg = CONFIG_BOOLEAN_NO;
}
else if(unlikely(!message_queue_root)) {
collector_info("Making chart %s (%s) obsolete since it does not have any dimensions", rrdset_name(st_msq_messages), rrdset_id(st_msq_messages));
rrdset_is_obsolete___safe_from_collector_thread(st_msq_messages);
st_msq_messages = NULL;
collector_info("Making chart %s (%s) obsolete since it does not have any dimensions", rrdset_name(st_msq_bytes), rrdset_id(st_msq_bytes));
rrdset_is_obsolete___safe_from_collector_thread(st_msq_bytes);
st_msq_bytes = NULL;
}
}
}
if(likely(do_shm != CONFIG_BOOLEAN_NO)) {
static RRDSET *st_shm_segments = NULL, *st_shm_bytes = NULL;
static RRDDIM *rd_shm_segments = NULL, *rd_shm_bytes = NULL;
struct shm_stats shm;
if(!ipc_shm_get_info(shm_filename, &shm)) {
if(unlikely(!st_shm_segments)) {
st_shm_segments = rrdset_create_localhost(
"system"
, "shared_memory_segments"
, NULL
, "ipc shared memory"
, NULL
, "IPC Shared Memory Number of Segments"
, "segments"
, PLUGIN_PROC_NAME
, "ipc"
, NETDATA_CHART_PRIO_SYSTEM_IPC_SHARED_MEM_SEGS
, update_every
, RRDSET_TYPE_STACKED
);
rd_shm_segments = rrddim_add(st_shm_segments, "segments", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
}
rrddim_set_by_pointer(st_shm_segments, rd_shm_segments, shm.segments);
rrdset_done(st_shm_segments);
if(unlikely(!st_shm_bytes)) {
st_shm_bytes = rrdset_create_localhost(
"system"
, "shared_memory_bytes"
, NULL
, "ipc shared memory"
, NULL
, "IPC Shared Memory Used Bytes"
, "bytes"
, PLUGIN_PROC_NAME
, "ipc"
, NETDATA_CHART_PRIO_SYSTEM_IPC_SHARED_MEM_SIZE
, update_every
, RRDSET_TYPE_STACKED
);
rd_shm_bytes = rrddim_add(st_shm_bytes, "bytes", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
}
rrddim_set_by_pointer(st_shm_bytes, rd_shm_bytes, shm.bytes);
rrdset_done(st_shm_bytes);
}
}
return 0;
}