usr: Add 'kstat' program for system info

The 'kstat' program provides kernel statistics and accounting
information

Signed-off-by: Ian Moffett <ian@osmora.org>

3 files changed, 80 insertions, 0 deletions

diff --git a/usr.bin/Makefile b/usr.bin/Makefile
index e84831a..f30905e 100644
--- a/usr.bin/Makefile
+++ b/usr.bin/Makefile
@@ -20,3 +20,4 @@ all:
 	make -C readcore/ $(ARGS)
 	make -C login/ $(ARGS)
 	make -C sleep/ $(ARGS)
+	make -C kstat/ $(ARGS)
diff --git a/usr.bin/kstat/Makefile b/usr.bin/kstat/Makefile
new file mode 100644
index 0000000..ccceb3c
--- /dev/null
+++ b/usr.bin/kstat/Makefile
@@ -0,0 +1,6 @@
+include user.mk
+
+CFILES = $(shell find . -name "*.c")
+
+$(ROOT)/base/usr/bin/kstat:
+	gcc $(CFILES) -o $@ $(INTERNAL_CFLAGS)
diff --git a/usr.bin/kstat/kstat.c b/usr.bin/kstat/kstat.c
new file mode 100644
index 0000000..853bc8b
--- /dev/null
+++ b/usr.bin/kstat/kstat.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2023-2025 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/sched.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+static void
+get_sched_stat(void)
+{
+    struct sched_stat stat;
+    struct sched_cpu *cpu;
+    int fd;
+
+    fd = open("/ctl/sched/stat", O_RDONLY);
+    if (fd < 0) {
+        printf("failed to get sched stat\n");
+        return;
+    }
+    if (read(fd, &stat, sizeof(stat)) < 0) {
+        printf("failed to read sched stat\n");
+        return;
+    }
+
+    close(fd);
+    printf("-------------------------------\n");
+    printf("Number of tasks: %d\n", stat.nproc);
+    printf("Number of cores online: %d\n", stat.ncpu);
+    printf("Scheduler quantum: %d usec\n", stat.quantum_usec);
+    printf("-------------------------------\n");
+
+    /*
+     * Log out some per-cpu information
+     */
+    for (int i = 0; i < stat.ncpu; ++i) {
+        cpu = &stat.cpus[i];
+        printf("[cpu %d]: %d switches\n", i, cpu->nswitch);
+    }
+}
+
+int
+main(void)
+{
+    get_sched_stat();
+    return 0;
+}