These code changes depend on the addition of control and worker
cpumask pointers to the ODP initialization parameter data structure,
and implement the change in behavior suggested with that patch.
They serve as the 'glue' between the input of the new ODP API
initial cpuset masks and the use of those new cpumasks by the
ODP application or instance.

Specifically: if both of the cpumask pointers are NULL or
if neither of the new cpumasks are populated prior to
calling odp_init_global(), then the behavior for allocation of
control and worker cpumasks is unchanged from its current
(pre-patch) state.

However, if the cpumasks are populated and their pointers initialized
prior to calling odp_init_global() then that routine saves
their contents into global variables for later reference.
Then when odp_cpumask_default_control() or odp_cpumask_default_worker()
are called they build the caller's cpumasks based on the
saved contents of the pre-populated cpumask input.

These changes allow multiple concurrent ODP applications
or instances to be given CPU resources which do not conflict
with one another, so multiple ODP instances can coexist harmoniously
with any isolation support on the underlying platform
as well as with one another.

Signed-off-by: Gary S. Robertson <gary.robert...@linaro.org>
---
 platform/linux-generic/include/odp_internal.h |  2 ++
 platform/linux-generic/odp_cpumask_task.c     | 48 ++++++++++++++++++++++-----
 platform/linux-generic/odp_init.c             | 19 +++++++++++
 platform/linux-generic/odp_system_info.c      | 13 +++-----
 4 files changed, 65 insertions(+), 17 deletions(-)

diff --git a/platform/linux-generic/include/odp_internal.h 
b/platform/linux-generic/include/odp_internal.h
index cdbed7d..7488b3b 100644
--- a/platform/linux-generic/include/odp_internal.h
+++ b/platform/linux-generic/include/odp_internal.h
@@ -38,6 +38,8 @@ struct odp_global_data_s {
        odp_log_func_t log_fn;
        odp_abort_func_t abort_fn;
        odp_system_info_t system_info;
+       odp_cpumask_t control_cpus;
+       odp_cpumask_t worker_cpus;
 };
 
 enum init_stage {
diff --git a/platform/linux-generic/odp_cpumask_task.c 
b/platform/linux-generic/odp_cpumask_task.c
index c5093e0..a5a9791 100644
--- a/platform/linux-generic/odp_cpumask_task.c
+++ b/platform/linux-generic/odp_cpumask_task.c
@@ -17,10 +17,27 @@ int odp_cpumask_default_worker(odp_cpumask_t *mask, int num)
        int ret, cpu, i;
        cpu_set_t cpuset;
 
-       ret = pthread_getaffinity_np(pthread_self(),
-                                    sizeof(cpu_set_t), &cpuset);
-       if (ret != 0)
-               ODP_ABORT("failed to read CPU affinity value\n");
+       CPU_ZERO(&cpuset);
+
+       /*
+        * If the available worker cpumask was specified prior to global init,
+        * then allocate worker CPUs from that cpumask.
+        */
+       if (odp_cpumask_count(&odp_global_data.worker_cpus)) {
+               for (i = 0; i < CPU_SETSIZE; i++)
+                       if (odp_cpumask_isset(&odp_global_data.worker_cpus, i))
+                               CPU_SET(i, &cpuset);
+       } else {
+               /*
+                * No initial worker cpumask was specified.
+                * So allocate worker CPUs from the available CPUs defined
+                * by the default OS environment.
+                */
+               ret = pthread_getaffinity_np(pthread_self(),
+                                            sizeof(cpu_set_t), &cpuset);
+               if (ret != 0)
+                       ODP_ABORT("failed to read CPU affinity value\n");
+       }
 
        odp_cpumask_zero(mask);
 
@@ -28,7 +45,7 @@ int odp_cpumask_default_worker(odp_cpumask_t *mask, int num)
         * If no user supplied number or it's too large, then attempt
         * to use all CPUs
         */
-       if (0 == num || CPU_SETSIZE < num)
+       if (0 == num || CPU_COUNT(&cpuset) < num)
                num = CPU_COUNT(&cpuset);
 
        /* build the mask, allocating down from highest numbered CPU */
@@ -48,10 +65,25 @@ int odp_cpumask_default_worker(odp_cpumask_t *mask, int num)
 
 int odp_cpumask_default_control(odp_cpumask_t *mask, int num ODP_UNUSED)
 {
+       int cpu_count = 0;
+
        odp_cpumask_zero(mask);
-       /* By default all control threads on CPU 0 */
-       odp_cpumask_set(mask, 0);
-       return 1;
+
+       /*
+        * If the available control cpumask was specified prior to global init,
+        * then allocate control CPUs from that cpumask.
+        */
+       cpu_count = odp_cpumask_count(&odp_global_data.control_cpus);
+       if (cpu_count)
+               odp_cpumask_copy(mask, &odp_global_data.control_cpus);
+
+       /* CPU 0 must always be usable for control threads */
+       if (!odp_cpumask_isset(mask, 0)) {
+               odp_cpumask_set(mask, 0);
+               cpu_count++;
+       }
+
+       return cpu_count;
 }
 
 int odp_cpumask_all_available(odp_cpumask_t *mask)
diff --git a/platform/linux-generic/odp_init.c 
b/platform/linux-generic/odp_init.c
index 6ad3320..38850ce 100644
--- a/platform/linux-generic/odp_init.c
+++ b/platform/linux-generic/odp_init.c
@@ -23,6 +23,25 @@ int odp_init_global(const odp_init_t *params,
                        odp_global_data.log_fn = params->log_fn;
                if (params->abort_fn != NULL)
                        odp_global_data.abort_fn = params->abort_fn;
+               /*
+                * Save the control and worker cpumask contents
+                * in a globally accessible data structure
+                * so odp_cpumask_default_control(),
+                * odp_cpumask_default_worker(), and any
+                * isolation support logic may reference them later.
+                */
+               if (params->control_cpus &&
+                   odp_cpumask_count(params->control_cpus))
+                       odp_cpumask_copy(&odp_global_data.control_cpus,
+                                        params->control_cpus);
+               else
+                       odp_cpumask_zero(&odp_global_data.control_cpus);
+               if (params->worker_cpus &&
+                   odp_cpumask_count(params->worker_cpus))
+                       odp_cpumask_copy(&odp_global_data.worker_cpus,
+                                        params->worker_cpus);
+               else
+                       odp_cpumask_zero(&odp_global_data.worker_cpus);
        }
 
        if (odp_time_init_global()) {
diff --git a/platform/linux-generic/odp_system_info.c 
b/platform/linux-generic/odp_system_info.c
index de28fab..70ebf57 100644
--- a/platform/linux-generic/odp_system_info.c
+++ b/platform/linux-generic/odp_system_info.c
@@ -8,6 +8,7 @@
 
 #include <odp/system_info.h>
 #include <odp_internal.h>
+#include <odp/cpumask.h>
 #include <odp_debug_internal.h>
 #include <odp/align.h>
 #include <odp/cpu.h>
@@ -39,19 +40,13 @@ typedef struct {
 
 
 /*
- * Report the number of CPUs in the affinity mask of the main thread
+ * Report the number of CPUs available to this ODP application / instance
  */
 static int sysconf_cpu_count(void)
 {
-       cpu_set_t cpuset;
-       int ret;
-
-       ret = pthread_getaffinity_np(pthread_self(),
-                                    sizeof(cpuset), &cpuset);
-       if (ret != 0)
-               return 0;
+       odp_cpumask_t mask;
 
-       return CPU_COUNT(&cpuset);
+       return odp_cpumask_all_available(&mask);
 }
 
 #if defined __x86_64__ || defined __i386__ || defined __OCTEON__ || \
-- 
1.9.1

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