[prev in list] [next in list] [prev in thread] [next in thread] 

List:       openvswitch-dev
Subject:    [ovs-dev] [PATCH] ovs-vswitchd: Add --mlockall option and enable on XenServer.
From:       jpettit () nicira ! com (Justin Pettit)
Date:       2009-11-30 21:32:59
Message-ID: AAF7BA71-195B-428F-8A58-AB08E45743CB () nicira ! com
[Download RAW message or body]

Looks like a good fix to me.

--Justin


On Nov 30, 2009, at 1:17 PM, Ben Pfaff wrote:

> On XenServer 5.5 we found that running 4 simultaneous vm-import operations
> on iSCSI caused so much disk and cache activity that (we suspect) parts of
> ovs-vswitchd were paged out to disk and were not paged back in for over
> 10 seconds, causing the XenServer to fall off the network and the XenCenter
> connection to fail.
> 
> Locking ovs-vswitchd into memory appears to avoid this problem.  Henrik
> reports that, with memory locking, importing 11 VMs simultaneously
> completed successfully.
> 
> Bug #2344.
> ---
> configure.ac                                      |    1 +
> vswitchd/ovs-vswitchd.8.in                        |   11 +++++++++++
> vswitchd/ovs-vswitchd.c                           |   15 +++++++++++++++
> xenserver/etc_init.d_vswitch                      |    8 ++++++--
> xenserver/root_vswitch_scripts_sysconfig.template |    7 +++++++
> 5 files changed, 40 insertions(+), 2 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index edfe0f7..239239e 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -47,6 +47,7 @@ OVS_CHECK_LINUX_VT_H
> OVS_CHECK_PCRE
> OVS_CHECK_IF_PACKET
> OVS_CHECK_STRTOK_R
> +AC_CHECK_FUNCS([mlockall])
> 
> if $build_userspace; then
> OVS_CHECK_PKIDIR
> diff --git a/vswitchd/ovs-vswitchd.8.in b/vswitchd/ovs-vswitchd.8.in
> index 5c8d6c7..e9c11f4 100644
> --- a/vswitchd/ovs-vswitchd.8.in
> +++ b/vswitchd/ovs-vswitchd.8.in
> @@ -67,6 +67,17 @@ Open vSwitch distribution for instructions on how to build and \
> load the Open vSwitch kernel module.
> .PP
> .SH OPTIONS
> +.IP "\fB--mlockall\fR"
> +Causes \fBovs\-vswitchd\fR to call the \fBmlockall()\fR function, to
> +attempt to lock all of its process memory into physical RAM,
> +preventing the kernel from paging any of its memory to disk.  This
> +helps to avoid networking interruptions due to system memory pressure.
> +.IP
> +Some systems do not support \fBmlockall()\fR at all, and other systems
> +only allow privileged users, such as the superuser, to use it.
> +\fBovs\-vswitchd\fR emits a log message if \fBmlockall()\fR is
> +unavailable or unsuccessful.
> +.
> .IP "\fB--fake-proc-net\fR"
> Causes \fBovs\-vswitchd\fR to simulate some files in \fB/proc/net/vlan\fR
> and \fB/proc/net/bonding\fR that some legacy software expects to
> diff --git a/vswitchd/ovs-vswitchd.c b/vswitchd/ovs-vswitchd.c
> index 01645ad..3309c08 100644
> --- a/vswitchd/ovs-vswitchd.c
> +++ b/vswitchd/ovs-vswitchd.c
> @@ -22,6 +22,9 @@
> #include <signal.h>
> #include <stdlib.h>
> #include <string.h>
> +#ifdef HAVE_MLOCKALL
> +#include <sys/mman.h>
> +#endif
> 
> #include "bridge.h"
> #include "cfg.h"
> @@ -148,6 +151,7 @@ parse_options(int argc, char *argv[])
> {
> enum {
> OPT_PEER_CA_CERT = UCHAR_MAX + 1,
> +        OPT_MLOCKALL,
> OPT_FAKE_PROC_NET,
> VLOG_OPTION_ENUMS,
> LEAK_CHECKER_OPTION_ENUMS
> @@ -155,6 +159,7 @@ parse_options(int argc, char *argv[])
> static struct option long_options[] = {
> {"help",        no_argument, 0, 'h'},
> {"version",     no_argument, 0, 'V'},
> +        {"mlockall",    no_argument, 0, OPT_MLOCKALL},
> {"fake-proc-net", no_argument, 0, OPT_FAKE_PROC_NET},
> DAEMON_LONG_OPTIONS,
> VLOG_LONG_OPTIONS,
> @@ -186,6 +191,16 @@ parse_options(int argc, char *argv[])
> OVS_PRINT_VERSION(OFP_VERSION, OFP_VERSION);
> exit(EXIT_SUCCESS);
> 
> +        case OPT_MLOCKALL:
> +#ifdef HAVE_MLOCKALL
> +            if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
> +                VLOG_ERR("mlockall failed: %s", strerror(errno));
> +            }
> +#else
> +            VLOG_ERR("mlockall not supported on this system");
> +#endif
> +            break;
> +
> case OPT_FAKE_PROC_NET:
> error = proc_net_compat_init();
> if (error) {
> diff --git a/xenserver/etc_init.d_vswitch b/xenserver/etc_init.d_vswitch
> index 4050d5a..e8e04ad 100755
> --- a/xenserver/etc_init.d_vswitch
> +++ b/xenserver/etc_init.d_vswitch
> @@ -34,6 +34,7 @@ VSWITCHD_CONF="${VSWITCHD_CONF:-/etc/ovs-vswitchd.conf}"
> VSWITCHD_PIDFILE="${VSWITCHD_PIDFILE:-/var/run/ovs-vswitchd.pid}"
> VSWITCHD_RUN_DIR="${VSWITCHD_RUN_DIR:-/var/xen/vswitch}"
> VSWITCHD_PRIORITY="${VSWITCHD_PRIORITY:--10}"
> +VSWITCHD_MLOCKALL="${VSWITCHD_MLOCKALL:-yes}"
> VSWITCHD_LOGFILE="${VSWITCHD_LOGFILE:-/var/log/ovs-vswitchd.log}"
> VSWITCHD_FILE_LOGLEVEL="${VSWITCHD_FILE_LOGLEVEL:-INFO}"
> VSWITCHD_SYSLOG_LOGLEVEL="${VSWITCHD_SYSLOG_LOGLEVEL:-ERR}"
> @@ -159,12 +160,15 @@ function start_vswitchd {
> if [ "$ENABLE_FAKE_PROC_NET" = "y" ]; then
> fake_proc_net_opt="--fake-proc-net"
> fi
> +    if [ "$VSWITCHD_MLOCKALL" != "no" ]; then
> +        mlockall_opt="--mlockall"
> +    fi
> if [ "$daemonize" != "y" ]; then
> # Start in background and force a "success" message
> action "Starting ovs-vswitchd ($strace_opt$valgrind_opt)" true
> -        (nice -n "$VSWITCHD_PRIORITY" $strace_opt $valgrind_opt "$vswitchd" \
> --pidfile="$VSWITCHD_PIDFILE" --detach --no-chdir $fake_proc_net_opt \
> -vANY:CONSOLE:EMER $syslog_opt $logfile_level_opt $logfile_file_opt $leak_opt \
> "$VSWITCHD_CONF") & +        (nice -n "$VSWITCHD_PRIORITY" $strace_opt \
> $valgrind_opt "$vswitchd" --pidfile="$VSWITCHD_PIDFILE" --detach --no-chdir \
> $fake_proc_net_opt -vANY:CONSOLE:EMER $syslog_opt $logfile_level_opt \
> $logfile_file_opt $leak_opt $mlockall_opt "$VSWITCHD_CONF") & else
> -        action "Starting ovs-vswitchd" nice -n "$VSWITCHD_PRIORITY" "$vswitchd" \
> --pidfile="$VSWITCHD_PIDFILE" --detach --no-chdir $fake_proc_net_opt \
> -vANY:CONSOLE:EMER $syslog_opt $logfile_level_opt $logfile_file_opt $leak_opt \
> "$VSWITCHD_CONF" +        action "Starting ovs-vswitchd" nice -n \
> "$VSWITCHD_PRIORITY" "$vswitchd" --pidfile="$VSWITCHD_PIDFILE" --detach --no-chdir \
> $fake_proc_net_opt -vANY:CONSOLE:EMER $syslog_opt $logfile_level_opt \
> $logfile_file_opt $leak_opt $mlockall_opt "$VSWITCHD_CONF" fi
> }
> 
> diff --git a/xenserver/root_vswitch_scripts_sysconfig.template \
> b/xenserver/root_vswitch_scripts_sysconfig.template index f848e7b..2578d11 100644
> --- a/xenserver/root_vswitch_scripts_sysconfig.template
> +++ b/xenserver/root_vswitch_scripts_sysconfig.template
> @@ -43,6 +43,13 @@
> #     processes.
> # VSWITCHD_PRIORITY=-10
> 
> +# VSWITCHD_MLOCKALL: Whether to pass ovs-vswitchd the --mlockall option.
> +#     This option should be set to "yes" or "no".  The default is "yes".
> +#     Enabling this option can avoid networking interruptions due to
> +#     system memory pressure in extraordinary situations, such as multiple
> +#     concurrent VM import operations.
> +# VSWITCHD_MLOCKALL=yes
> +
> # VSWITCHD_LOGFILE: File to send the FILE_LOGLEVEL log messages to.
> # VSWITCHD_LOGFILE=/var/log/ovs-vswitchd.log
> 
> -- 
> 1.6.3.3
> 
> 
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> http://openvswitch.org/mailman/listinfo/dev_openvswitch.org


[prev in list] [next in list] [prev in thread] [next in thread]