Real-time scheduling and memory locking is available on posix compliant
OSs. This patch centralizes this functionality and brings support to
FreeBSD, NetBSD, and Solaris.
---
configure | 27 ++++++++---
doc/chrony.conf.adoc | 46 +++++++++---------
sys.c | 13 +++--
sys_linux.c | 67 --------------------------
sys_linux.h | 4 --
sys_posix.c | 111 +++++++++++++++++++++++++++++++++++++++++++
sys_posix.h | 36 ++++++++++++++
7 files changed, 198 insertions(+), 106 deletions(-)
create mode 100644 sys_posix.c
create mode 100644 sys_posix.h
diff --git a/configure b/configure
index c434127..9e21a8b 100755
--- a/configure
+++ b/configure
@@ -396,7 +396,7 @@ SYSTEM=${OPERATINGSYSTEM}-${MACHINE}
case $OPERATINGSYSTEM in
Linux)
- EXTRA_OBJECTS="sys_generic.o sys_linux.o sys_timex.o"
+ EXTRA_OBJECTS="sys_generic.o sys_linux.o sys_timex.o sys_posix.o"
[ $try_libcap != "0" ] && try_libcap=1
try_rtc=1
[ $try_seccomp != "0" ] && try_seccomp=1
@@ -411,7 +411,9 @@ case $OPERATINGSYSTEM in
# recvmmsg() seems to be broken on FreeBSD 11.0 and it's just
# a wrapper around recvmsg()
try_recvmmsg=0
- EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o"
+ EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o sys_posix.o"
+ try_setsched=1
+ try_lockmem=1
add_def FREEBSD
if [ $feat_droproot = "1" ]; then
add_def FEAT_PRIVDROP
@@ -420,8 +422,10 @@ case $OPERATINGSYSTEM in
echo "Configuring for $SYSTEM"
;;
NetBSD)
- EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o"
+ EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o sys_posix.o"
try_clockctl=1
+ try_setsched=1
+ try_lockmem=1
add_def NETBSD
echo "Configuring for $SYSTEM"
;;
@@ -446,9 +450,11 @@ case $OPERATINGSYSTEM in
echo "Configuring for macOS (" $SYSTEM "macOS version" $VERSION ")"
;;
SunOS)
- EXTRA_OBJECTS="sys_generic.o sys_solaris.o sys_timex.o"
+ EXTRA_OBJECTS="sys_generic.o sys_solaris.o sys_timex.o sys_posix.o"
EXTRA_LIBS="-lsocket -lnsl -lresolv"
EXTRA_CLI_LIBS="-lsocket -lnsl -lresolv"
+ try_setsched=1
+ try_lockmem=1
add_def SOLARIS
# These are needed to have msg_control in struct msghdr
add_def __EXTENSIONS__
@@ -800,13 +806,20 @@ fi
if [ $try_lockmem = "1" ] && \
test_code \
'mlockall()' \
- 'sys/mman.h sys/resource.h' '' '' '
- struct rlimit rlim;
- setrlimit(RLIMIT_MEMLOCK, &rlim);
+ 'sys/mman.h' '' '' '
mlockall(MCL_CURRENT|MCL_FUTURE);'
then
add_def HAVE_MLOCKALL
fi
+if [ $try_lockmem = "1" ] && \
+ test_code \
+ 'setrlimit(RLIMIT_MEMLOCK, ...)' \
+ 'sys/resource.h' '' '' '
+ struct rlimit rlim;
+ setrlimit(RLIMIT_MEMLOCK, &rlim);'
+then
+ add_def HAVE_SETRLIMIT_MEMLOCK
+fi
if [ $feat_forcednsretry = "1" ]
then
diff --git a/doc/chrony.conf.adoc b/doc/chrony.conf.adoc
index 7aa2116..aa5cafe 100644
--- a/doc/chrony.conf.adoc
+++ b/doc/chrony.conf.adoc
@@ -2063,11 +2063,11 @@ file when the <<chronyc.adoc#rekey,*rekey*>> command is
issued by *chronyc*).
[[lock_all]]*lock_all*::
The *lock_all* directive will lock chronyd into RAM so that it will never be
-paged out. This mode is only supported on Linux. This directive uses the Linux
-*mlockall()* system call to prevent *chronyd* from ever being swapped out. This
-should result in lower and more consistent latency. It should not have
-significant impact on performance as *chronyd's* memory usage is modest. The
-*mlockall(2)* man page has more details.
+paged out. This mode is supported on Linux, FreeBSD, NetBSD, and Solaris. This
+directive uses the POSIX *mlockall()* system call to prevent *chronyd* from
+ever being swapped out. This should result in lower and more consistent
+latency. It should not have significant impact on performance as *chronyd's*
+memory usage is modest. The *mlockall(2)* man page has more details.
[[pidfile]]*pidfile* _file_::
Unless *chronyd* is started with the *-Q* option, it writes its process ID
@@ -2081,26 +2081,26 @@ pidfile /run/chronyd.pid
----
[[sched_priority]]*sched_priority* _priority_::
-On Linux, the *sched_priority* directive will select the SCHED_FIFO real-time
-scheduler at the specified priority (which must be between 0 and 100). On
-macOS, this option must have either a value of 0 (the default) to disable the
-thread time constraint policy or 1 for the policy to be enabled. Other systems
-do not support this option.
-+
-On Linux, this directive uses the *sched_setscheduler()* system call to
-instruct the kernel to use the SCHED_FIFO first-in, first-out real-time
-scheduling policy for *chronyd* with the specified priority. This means that
-whenever *chronyd* is ready to run it will run, interrupting whatever else is
-running unless it is a higher priority real-time process. This should not
-impact performance as *chronyd* resource requirements are modest, but it should
-result in lower and more consistent latency since *chronyd* will not need to
-wait for the scheduler to get around to running it. You should not use this
-unless you really need it. The *sched_setscheduler(2)* man page has more
-details.
+On Linux, FreeBSD, NetBSD, and Solaris, the *sched_priority* directive will
+select the SCHED_FIFO real-time scheduler at the specified priority (which must
+be between 0 and 100). On macOS, this option must have either a value of 0 (the
+default) to disable the thread time constraint policy or 1 for the policy to be
+enabled.
++
+On systems other than macOS, this directive uses the *pthread_setschedparam()*
+system call to instruct the kernel to use the SCHED_FIFO first-in, first-out
+real-time scheduling policy for *chronyd* with the specified priority. This
+means that whenever *chronyd* is ready to run it will run, interrupting
+whatever else is running unless it is a higher priority real-time process. This
+should not impact performance as *chronyd* resource requirements are modest,
+but it should result in lower and more consistent latency since *chronyd* will
+not need to wait for the scheduler to get around to running it. You should not
+use this unless you really need it. The *pthread_setschedparam(3)* man page has
+more details.
+
On macOS, this directive uses the *thread_policy_set()* kernel call to
-specify real-time scheduling. As noted for Linux, you should not use this
-directive unless you really need it.
+specify real-time scheduling. As noted above, you should not use this directive
+unless you really need it.
[[user]]*user* _user_::
The *user* directive sets the name of the system user to which *chronyd* will
diff --git a/sys.c b/sys.c
index 2c42db1..a49ea5f 100644
--- a/sys.c
+++ b/sys.c
@@ -35,10 +35,13 @@
#if defined(LINUX)
#include "sys_linux.h"
+#include "sys_posix.h"
#elif defined(SOLARIS)
#include "sys_solaris.h"
+#include "sys_posix.h"
#elif defined(NETBSD) || defined(FREEBSD)
#include "sys_netbsd.h"
+#include "sys_posix.h"
#elif defined(MACOSX)
#include "sys_macosx.h"
#endif
@@ -124,10 +127,10 @@ void SYS_EnableSystemCallFilter(int level)
void SYS_SetScheduler(int SchedPriority)
{
-#if defined(LINUX) && defined(HAVE_PTHREAD_SETSCHEDPARAM)
- SYS_Linux_SetScheduler(SchedPriority);
-#elif defined(MACOSX)
+#if defined(MACOSX)
SYS_MacOSX_SetScheduler(SchedPriority);
+#elif defined(HAVE_PTHREAD_SETSCHEDPARAM)
+ SYS_Posix_SetScheduler(SchedPriority);
#else
LOG_FATAL("scheduler priority setting not supported");
#endif
@@ -137,8 +140,8 @@ void SYS_SetScheduler(int SchedPriority)
void SYS_LockMemory(void)
{
-#if defined(LINUX) && defined(HAVE_MLOCKALL)
- SYS_Linux_MemLockAll(1);
+#if defined(HAVE_MLOCKALL)
+ SYS_Posix_MemLockAll(1);
#else
LOG_FATAL("memory locking not supported");
#endif
diff --git a/sys_linux.c b/sys_linux.c
index 9e4ab3f..898dc7a 100644
--- a/sys_linux.c
+++ b/sys_linux.c
@@ -33,16 +33,6 @@
#include <sys/utsname.h>
-#if defined(HAVE_PTHREAD_SETSCHEDPARAM)
-# include <pthread.h>
-# include <sched.h>
-#endif
-
-#if defined(HAVE_MLOCKALL)
-# include <sys/mman.h>
-#include <sys/resource.h>
-#endif
-
#if defined(FEAT_PHC) || defined(HAVE_LINUX_TIMESTAMPING)
#include <linux/ptp_clock.h>
#endif
@@ -633,63 +623,6 @@ add_failed:
/* ================================================== */
-#if defined(HAVE_PTHREAD_SETSCHEDPARAM)
- /* Install SCHED_FIFO real-time scheduler with specified priority */
-void SYS_Linux_SetScheduler(int SchedPriority)
-{
- int pmax, pmin;
- struct sched_param sched;
-
- if (SchedPriority < 1 || SchedPriority > 99) {
- LOG_FATAL("Bad scheduler priority: %d", SchedPriority);
- } else {
- sched.sched_priority = SchedPriority;
- pmax = sched_get_priority_max(SCHED_FIFO);
- pmin = sched_get_priority_min(SCHED_FIFO);
- if ( SchedPriority > pmax ) {
- sched.sched_priority = pmax;
- }
- else if ( SchedPriority < pmin ) {
- sched.sched_priority = pmin;
- }
- if ( pthread_setschedparam(pthread_self(), SCHED_FIFO, &sched) == -1 ) {
- 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_Linux_MemLockAll(int LockAll)
-{
- struct rlimit rlim;
- if (LockAll == 1 ) {
- /* Make sure that we will be able to lock all the memory we need */
- /* even after dropping privileges. This does not actually reaerve any
memory */
- rlim.rlim_max = RLIM_INFINITY;
- rlim.rlim_cur = RLIM_INFINITY;
- if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0) {
- LOG(LOGS_ERR, "setrlimit() failed: not locking into RAM");
- }
- else {
- if (mlockall(MCL_CURRENT|MCL_FUTURE) < 0) {
- LOG(LOGS_ERR, "mlockall() failed");
- }
- else {
- DEBUG_LOG("Successfully locked into RAM");
- }
- }
- }
-}
-#endif /* HAVE_MLOCKALL */
-
-/* ================================================== */
-
int
SYS_Linux_CheckKernelVersion(int req_major, int req_minor)
{
diff --git a/sys_linux.h b/sys_linux.h
index 799ae9a..551a186 100644
--- a/sys_linux.h
+++ b/sys_linux.h
@@ -35,10 +35,6 @@ extern void SYS_Linux_DropRoot(uid_t uid, gid_t gid, int
clock_control);
extern void SYS_Linux_EnableSystemCallFilter(int level);
-extern void SYS_Linux_MemLockAll(int LockAll);
-
-extern void SYS_Linux_SetScheduler(int SchedPriority);
-
extern int SYS_Linux_CheckKernelVersion(int req_major, int req_minor);
extern int SYS_Linux_OpenPHC(const char *path, int phc_index);
diff --git a/sys_posix.c b/sys_posix.c
new file mode 100644
index 0000000..c40dfbf
--- /dev/null
+++ b/sys_posix.c
@@ -0,0 +1,111 @@
+/*
+ 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 SchedPriority)
+{
+ int pmax, pmin;
+ struct sched_param sched;
+
+ if (SchedPriority < 1 || SchedPriority > 99) {
+ LOG_FATAL("Bad scheduler priority: %d", SchedPriority);
+ } else {
+ sched.sched_priority = SchedPriority;
+ pmax = sched_get_priority_max(SCHED_FIFO);
+ pmin = sched_get_priority_min(SCHED_FIFO);
+ if (SchedPriority > pmax) {
+ sched.sched_priority = pmax;
+ } else if (SchedPriority < pmin) {
+ sched.sched_priority = pmin;
+ }
+
+ if (pthread_setschedparam(pthread_self(), SCHED_FIFO, &sched) == -1) {
+ 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(int LockAll)
+{
+ if (LockAll == 1 ) {
+#if defined(HAVE_SETRLIMIT_MEMLOCK)
+ /* Ensure we can reserve as much as we need */
+ struct rlimit rlim;
+ 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 */
+
diff --git a/sys_posix.h b/sys_posix.h
new file mode 100644
index 0000000..2138c16
--- /dev/null
+++ b/sys_posix.h
@@ -0,0 +1,36 @@
+/*
+ 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.
+ *
+ **********************************************************************
+
+ =======================================================================
+
+ The header file for shared Posix functionality
+ */
+
+#ifndef GOT_SYS_POSIX_H
+#define GOT_SYS_POSIX_H
+
+extern void SYS_Posix_MemLockAll(int LockAll);
+
+extern void SYS_Posix_SetScheduler(int SchedPriority);
+
+#endif /* GOT_SYS_POSIX_H */
--
2.21.0
Hi,
Updated patch based on feedback. The documentation changes are actually
quite minor and can be best viewed locally with git diff --word-diff.
I re-tested on the aforementioned systems.
Let me know if you see room for improvement.
Regards,
Stefan
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