Hi Hans,
The reason for code existing to the failure of "sched_setscheduler()" is
to continue with *default values* by any chance if it fails with the
user defined values given through env-var settings "*__SCHED_PRIORITY"
and "*_SCHED_POLICY".
Thanks,
Ramesh.
On 9/18/2013 2:49 PM, Hans Feldt wrote:
> osaf/libs/core/common/daemon.c | 23 ++++++++++++++++++-----
> osaf/libs/core/leap/os_defs.c | 8 --------
> 2 files changed, 18 insertions(+), 13 deletions(-)
>
>
> In ncs_os_process_execute_timed() non async signal safe functions are used
> between fork() and exec(). That can cause undeterministic behaviour in the
> child and cause problems for AMF to provide service.
>
> The amfnd main thread runs with RT scheduling policy and
> ncs_os_process_execute_timed() needs to guarantee that child processes get
> normal scheduling policy and not just inherits the callers policy.
>
> By adding the SCHED_RESET_ON_FORK option to the sched_setscheduler system call
> it is guaranteed by the kernel that all child processes gets normal
> scheduling policy. No matter the policy of the parent process/thread.
>
> diff --git a/osaf/libs/core/common/daemon.c b/osaf/libs/core/common/daemon.c
> --- a/osaf/libs/core/common/daemon.c
> +++ b/osaf/libs/core/common/daemon.c
> @@ -40,6 +40,15 @@
> #include <ncsgl_defs.h>
> #include <os_defs.h>
>
> +/*
> + * See "man 2 sched_setscheduler"
> + * SCHED_RESET_ON_FORK is supported from Linux 2.6.32 but is not in POSIX
> (yet)
> + * SCHED_RESET_ON_FORK is defined in <linux/sched.h>
> + * The above file cannot be included because it will break an LSB build
> + * We trust that the Linux kernel ABI will never change and is backwards
> + * compatible thus it is safe to define our own constant here.
> + */
> +#define SCHED_RESET_ON_FORK 0x40000000
>
> #define DEFAULT_RUNAS_USERNAME "opensaf"
>
> @@ -216,6 +225,7 @@ void daemonize(int argc, char *argv[])
> {
> policy = SCHED_RR;
> prio_val = sched_get_priority_min(policy);
> + policy |= SCHED_RESET_ON_FORK;
> }
>
> strcpy(t_str, basename(argv[0]));
> @@ -235,14 +245,17 @@ void daemonize(int argc, char *argv[])
>
> param.sched_priority = prio_val;
> if (sched_setscheduler(0, policy, ¶m) == -1) {
> - syslog(LOG_ERR, "Could not set scheduling class for %s",
> strerror(errno));
> + syslog(LOG_ERR, "daemonize: could not set scheduling class -
> %s", strerror(errno));
> if( (!strncmp("osafamfwd", basename(argv[0]), 9)) ||
> (!strncmp("osafamfnd", basename(argv[0]), 9)))
> {
> - policy = SCHED_RR;
> + syslog(LOG_NOTICE, "daemonize: setting scheduler policy
> to OTHER");
> + syslog(LOG_WARNING, "daemonize: this system is not
> correctly configured");
> + policy = SCHED_OTHER;
> param.sched_priority = sched_get_priority_min(policy);
> - syslog(LOG_INFO, "setting to default values");
> - if (sched_setscheduler(0, policy, ¶m) == -1)
> - syslog(LOG_ERR, "Could not set scheduling class
> for %s", strerror(errno));
> + if (sched_setscheduler(0, policy, ¶m) == -1) {
> + syslog(LOG_ERR, "daemonize: could not set
> scheduling class, exiting");
> + exit(EXIT_FAILURE);
> + }
> }
> }
>
> diff --git a/osaf/libs/core/leap/os_defs.c b/osaf/libs/core/leap/os_defs.c
> --- a/osaf/libs/core/leap/os_defs.c
> +++ b/osaf/libs/core/leap/os_defs.c
> @@ -999,14 +999,6 @@ uint32_t ncs_os_process_execute_timed(NC
> osaf_mutex_lock_ordie(&s_cloexec_mutex);
>
> if ((pid = fork()) == 0) {
> - /*
> - ** Make sure forked processes have default scheduling class
> - ** independent of the callers scheduling class.
> - */
> - struct sched_param param = {.sched_priority = 0 };
> - if (sched_setscheduler(0, SCHED_OTHER, ¶m) == -1)
> - syslog(LOG_ERR, "%s: Could not setscheduler: %s",
> __FUNCTION__, strerror(errno));
> -
> /* set the environment variables */
> for (; count > 0; count--) {
> setenv(node->name, node->value, node->overwrite);
------------------------------------------------------------------------------
LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99!
1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint
2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes
Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13.
http://pubads.g.doubleclick.net/gampad/clk?id=58041151&iu=/4140/ostg.clktrk
_______________________________________________
Opensaf-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/opensaf-devel
