1 files changed, 66 insertions, 0 deletions
diff --git a/sys/os/os_sched.c b/sys/os/os_sched.c
new file mode 100644
index 0000000..e0dfc98
--- /dev/null
+++ b/sys/os/os_sched.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/queue.h>
+#include <os/sched.h>
+#include <os/trace.h>
+#include <mu/cpu.h>
+
+struct cpu_info *
+sched_enqueue_proc(struct process *proc)
+{
+    struct cpu_info *core;
+    size_t ncpu, i;
+
+    if (proc == NULL) {
+        return NULL;
+    }
+
+    if (proc->affinity >= 0) {
+        if ((core = cpu_get(proc->affinity)) != NULL)
+            return core;
+    }
+
+    /*
+     * Here, we derive the processor index by using the lower
+     * byte MOD the number of cores, this works best and most
+     * evenly when the PID assignment increments monotonically
+     * though could potentially work with random assignment, just
+     * more sporadic.
+     */
+    ncpu = cpu_count();
+    i = (proc->pid & 0xFF) % ncpu;
+    while ((core = cpu_get(i++)) == NULL) {
+        if (i > ncpu) {
+            i = 0;
+        }
+    }
+    TAILQ_INSERT_TAIL(&core->pqueue, proc, link);
+    return core;
+}