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Diffstat (limited to 'sys_posix.c')
-rw-r--r-- | sys_posix.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/sys_posix.c b/sys_posix.c new file mode 100644 index 0000000..356e86a --- /dev/null +++ b/sys_posix.c @@ -0,0 +1,109 @@ +/* + chronyd/chronyc - Programs for keeping computer clocks accurate. + + ********************************************************************** + * Copyright (C) Richard P. Curnow 1997-2003 + * Copyright (C) John G. Hasler 2009 + * Copyright (C) Miroslav Lichvar 2009-2012, 2014-2018 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + ********************************************************************** + + ======================================================================= + + This module is for POSIX compliant operating systems. + + */ + +#include "config.h" + +#include "sysincl.h" + +#include <sys/utsname.h> + +#if defined(HAVE_PTHREAD_SETSCHEDPARAM) +#include <pthread.h> +#include <sched.h> +#endif + +#if defined(HAVE_MLOCKALL) +#include <sys/mman.h> +#endif +#if defined(HAVE_SETRLIMIT_MEMLOCK) +#include <sys/resource.h> +#endif + +#include "sys_posix.h" +#include "conf.h" +#include "local.h" +#include "logging.h" +#include "util.h" + +/* ================================================== */ + +#if defined(HAVE_PTHREAD_SETSCHEDPARAM) +/* Install SCHED_FIFO real-time scheduler with specified priority */ +void +SYS_Posix_SetScheduler(int priority) +{ + struct sched_param sched; + int pmax, pmin; + + if (priority < 1 || priority > 99) + LOG_FATAL("Bad scheduler priority: %d", priority); + + sched.sched_priority = priority; + pmax = sched_get_priority_max(SCHED_FIFO); + pmin = sched_get_priority_min(SCHED_FIFO); + if (priority > pmax) { + sched.sched_priority = pmax; + } else if (priority < pmin) { + sched.sched_priority = pmin; + } + + if (pthread_setschedparam(pthread_self(), SCHED_FIFO, &sched) < 0) { + LOG(LOGS_ERR, "pthread_setschedparam() failed"); + } else { + DEBUG_LOG("Enabled SCHED_FIFO with priority %d", sched.sched_priority); + } +} +#endif /* HAVE_PTHREAD_SETSCHEDPARAM */ + +/* ================================================== */ + +#if defined(HAVE_MLOCKALL) +/* Lock the process into RAM so that it will never be swapped out */ +void +SYS_Posix_MemLockAll(void) +{ +#if defined(HAVE_SETRLIMIT_MEMLOCK) + struct rlimit rlim; + + /* Ensure we can reserve as much as we need */ + rlim.rlim_max = RLIM_INFINITY; + rlim.rlim_cur = RLIM_INFINITY; + if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0) { + LOG(LOGS_ERR, "setrlimit() failed"); + return; + } +#endif + + if (mlockall(MCL_CURRENT|MCL_FUTURE) < 0) { + LOG(LOGS_ERR, "mlockall() failed"); + } else { + DEBUG_LOG("Successfully locked into RAM"); + } +} +#endif /* HAVE_MLOCKALL */ |