// SPDX-License-Identifier: GPL-3.0-or-later #include "plugin_proc.h" #include #include #include #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 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)) { error("IPC: Cannot open file '%s'.", filename); error_shown = 1; } goto ipc; } } ff = procfile_readall(ff); if(unlikely(!ff)) { if(unlikely(!error_shown)) { 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)) { 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)) { 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)) { 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 do_ipc(int update_every, usec_t dt) { (void)dt; static int initialized = 0, read_limits_next = -1; static struct ipc_limits limits; static struct ipc_status status; static RRDVAR *arrays_max = NULL, *semaphores_max = NULL; static RRDSET *st_semaphores = NULL, *st_arrays = NULL; static RRDDIM *rd_semaphores = NULL, *rd_arrays = NULL; if(unlikely(!initialized)) { initialized = 1; // make sure it works if(ipc_sem_get_limits(&limits) == -1) { error("unable to fetch semaphore limits"); return 1; } // make sure it works if(ipc_sem_get_status(&status) == -1) { error("unable to fetch semaphore statistics"); return 1; } // 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_custom_host_variable_create(localhost, "ipc_semaphores_max"); arrays_max = rrdvar_custom_host_variable_create(localhost, "ipc_semaphores_arrays_max"); } if(unlikely(read_limits_next < 0)) { if(unlikely(ipc_sem_get_limits(&limits) == -1)) { error("Unable to fetch semaphore limits."); } else { if(semaphores_max) rrdvar_custom_host_variable_set(localhost, semaphores_max, limits.semmns); if(arrays_max) rrdvar_custom_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)) { error("Unable to get semaphore statistics"); return 0; } if(st_semaphores->counter_done) rrdset_next(st_semaphores); rrddim_set_by_pointer(st_semaphores, rd_semaphores, status.semaem); rrdset_done(st_semaphores); if(st_arrays->counter_done) rrdset_next(st_arrays); rrddim_set_by_pointer(st_arrays, rd_arrays, status.semusz); rrdset_done(st_arrays); return 0; }