[v14,5/9] eal: implement thread priority management functions
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Commit Message
From: Narcisa Vasile <navasile@microsoft.com>
Add function for setting the priority for a thread.
Priorities on multiple platforms are similarly determined by
a priority value and a priority class/policy.
On Linux, the following mapping is created:
RTE_THREAD_PRIORITY_NORMAL corresponds to
* policy SCHED_OTHER
* priority value: (sched_get_priority_min(SCHED_OTHER) +
sched_get_priority_max(SCHED_OTHER))/2;
RTE_THREAD_PRIORITY_REALTIME_CRITICAL corresponds to
* policy SCHED_RR
* priority value: sched_get_priority_max(SCHED_RR);
On Windows, the following mapping is created:
RTE_THREAD_PRIORITY_NORMAL corresponds to
* class NORMAL_PRIORITY_CLASS
* priority THREAD_PRIORITY_NORMAL
RTE_THREAD_PRIORITY_REALTIME_CRITICAL corresponds to
* class REALTIME_PRIORITY_CLASS
* priority THREAD_PRIORITY_TIME_CRITICAL
Signed-off-by: Narcisa Vasile <navasile@microsoft.com>
---
lib/eal/common/rte_thread.c | 49 ++++++++++++++++++++++++++
lib/eal/include/rte_thread.h | 17 ++++++++++
lib/eal/version.map | 1 +
lib/eal/windows/rte_thread.c | 66 ++++++++++++++++++++++++++++++++++++
4 files changed, 133 insertions(+)
@@ -50,6 +50,55 @@ rte_thread_get_affinity_by_id(rte_thread_t thread_id,
sizeof(*cpuset), cpuset);
}
+static int
+thread_map_priority_to_os_value(enum rte_thread_priority eal_pri,
+ int *os_pri, int *pol)
+{
+ /* Clear the output parameters */
+ *os_pri = sched_get_priority_min(SCHED_OTHER) - 1;
+ *pol = -1;
+
+ switch (eal_pri) {
+ case RTE_THREAD_PRIORITY_NORMAL:
+ *pol = SCHED_OTHER;
+
+ /*
+ * Choose the middle of the range to represent
+ * the priority 'normal'.
+ * On Linux, this should be 0, since both
+ * sched_get_priority_min/_max return 0 for SCHED_OTHER.
+ */
+ *os_pri = (sched_get_priority_min(SCHED_OTHER) +
+ sched_get_priority_max(SCHED_OTHER))/2;
+ break;
+ case RTE_THREAD_PRIORITY_REALTIME_CRITICAL:
+ *pol = SCHED_RR;
+ *os_pri = sched_get_priority_max(SCHED_RR);
+ break;
+ default:
+ RTE_LOG(DEBUG, EAL, "The requested priority value is invalid.\n");
+ return EINVAL;
+ }
+ return 0;
+}
+
+int
+rte_thread_set_priority(rte_thread_t thread_id,
+ enum rte_thread_priority priority)
+{
+ int ret;
+ int policy;
+ struct sched_param param;
+
+ ret = thread_map_priority_to_os_value(priority, ¶m.sched_priority,
+ &policy);
+ if (ret != 0)
+ return ret;
+
+ return pthread_setschedparam((pthread_t)thread_id.opaque_id,
+ policy, ¶m);
+}
+
int
rte_thread_attr_init(rte_thread_attr_t *attr)
{
@@ -213,6 +213,23 @@ void rte_thread_get_affinity(rte_cpuset_t *cpusetp);
#endif /* RTE_HAS_CPUSET */
+/**
+ * Set the priority of a thread.
+ *
+ * @param thread_id
+ * Id of the thread for which to set priority.
+ *
+ * @param priority
+ * Priority value to be set.
+ *
+ * @return
+ * On success, return 0.
+ * On failure, return a positive errno-style error number.
+ */
+__rte_experimental
+int rte_thread_set_priority(rte_thread_t thread_id,
+ enum rte_thread_priority priority);
+
/**
* Create a TLS data key visible to all threads in the process.
* the created key is later used to get/set a value.
@@ -435,6 +435,7 @@ EXPERIMENTAL {
rte_thread_attr_set_priority;
rte_thread_get_affinity_by_id;
rte_thread_set_affinity_by_id;
+ rte_thread_set_priority;
};
INTERNAL {
@@ -200,6 +200,72 @@ rte_thread_get_affinity_by_id(rte_thread_t thread_id,
return ret;
}
+static int
+thread_map_priority_to_os_value(enum rte_thread_priority eal_pri,
+ int *os_pri, int *pri_class)
+{
+ /* Clear the output parameters */
+ *os_pri = -1;
+ *pri_class = -1;
+
+ switch (eal_pri) {
+ case RTE_THREAD_PRIORITY_NORMAL:
+ *pri_class = NORMAL_PRIORITY_CLASS;
+ *os_pri = THREAD_PRIORITY_NORMAL;
+ break;
+ case RTE_THREAD_PRIORITY_REALTIME_CRITICAL:
+ *pri_class = REALTIME_PRIORITY_CLASS;
+ *os_pri = THREAD_PRIORITY_TIME_CRITICAL;
+ break;
+ default:
+ RTE_LOG(DEBUG, EAL, "The requested priority value is invalid.\n");
+ return EINVAL;
+ }
+
+ return 0;
+}
+
+int
+rte_thread_set_priority(rte_thread_t thread_id,
+ enum rte_thread_priority priority)
+{
+ HANDLE thread_handle;
+ int priority_class;
+ int os_priority;
+ int ret = 0;
+
+ thread_handle = OpenThread(THREAD_SET_INFORMATION |
+ THREAD_QUERY_INFORMATION, FALSE,
+ thread_id.opaque_id);
+ if (thread_handle == NULL) {
+ ret = thread_log_last_error("OpenThread()");
+ goto cleanup;
+ }
+
+ ret = thread_map_priority_to_os_value(priority, &os_priority,
+ &priority_class);
+ if (ret != 0)
+ goto cleanup;
+
+ if (!SetPriorityClass(GetCurrentProcess(), priority_class)) {
+ ret = thread_log_last_error("SetPriorityClass()");
+ goto cleanup;
+ }
+
+ if (!SetThreadPriority(thread_handle, os_priority)) {
+ ret = thread_log_last_error("SetThreadPriority()");
+ goto cleanup;
+ }
+
+cleanup:
+ if (thread_handle != NULL) {
+ CloseHandle(thread_handle);
+ thread_handle = NULL;
+ }
+
+ return ret;
+}
+
int
rte_thread_attr_init(rte_thread_attr_t *attr)
{