Make it possible to reread and update detected CPU information

Calling erlang:system_info/1 with the new argument 'update_cpu_info'
will make the runtime system reread and update the internally stored
CPU information. For more information see the documentation of
erlang:system_info(update_cpu_info).

1 files changed, 34 insertions, 1 deletions

diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index a644520442..457e283034 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -3962,7 +3962,7 @@ check_cpu_bind(ErtsSchedulerData *esdp)
 		goto unbind;
 	}
     }
-    else if (cpu_id < 0 && scheduler2cpu_map[esdp->no].bound_id >= 0) {
+    else if (cpu_id < 0) /* && scheduler2cpu_map[esdp->no].bound_id >= 0) */ {
     unbind:
 	/* Get rid of old binding */
 	res = erts_unbind_from_cpu(erts_cpuinfo);
@@ -5521,6 +5521,39 @@ late_cpu_bind_init(void)
     }
 }
 
+int
+erts_update_cpu_info(void)
+{
+    int changed;
+    erts_smp_rwmtx_rwlock(&erts_cpu_bind_rwmtx);
+    changed = erts_cpu_info_update(erts_cpuinfo);
+    if (changed) {
+	erts_cpu_topology_t *cpudata;
+	int cpudata_size;
+	erts_free(ERTS_ALC_T_CPUDATA, system_cpudata);
+
+	system_cpudata_size = erts_get_cpu_topology_size(erts_cpuinfo);
+	system_cpudata = erts_alloc(ERTS_ALC_T_CPUDATA,
+				    (sizeof(erts_cpu_topology_t)
+				     * system_cpudata_size));
+
+	if (!erts_get_cpu_topology(erts_cpuinfo, system_cpudata)
+	    || ERTS_INIT_CPU_TOPOLOGY_OK != verify_topology(system_cpudata,
+							    system_cpudata_size)) {
+	    erts_free(ERTS_ALC_T_CPUDATA, system_cpudata);
+	    system_cpudata = NULL;
+	    system_cpudata_size = 0;
+	}
+
+	create_tmp_cpu_topology_copy(&cpudata, &cpudata_size);
+	ASSERT(cpudata);
+	signal_schedulers_bind_change(cpudata, cpudata_size);
+	destroy_tmp_cpu_topology_copy(cpudata);
+    }
+    erts_smp_rwmtx_rwunlock(&erts_cpu_bind_rwmtx);
+    return changed;
+}
+
 #ifdef ERTS_SMP
 
 static void