From 15b1b4d0fb491ab0bcde821b37ec13876d48a56c Mon Sep 17 00:00:00 2001
From: "leon.bohnwagner" <leon.bohnwagner@informatik.hs-fulda.de>
Date: Wed, 12 Feb 2025 18:59:26 +0100
Subject: [PATCH] feat: add hrtimer to kernel module
---
kernel/kmod.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c
index cb13bab..e29d238 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -4,17 +4,23 @@
#include <linux/cdev.h>
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
+#include <linux/hrtimer.h>
#include "../common/include/message.h"
#define DEVICE_NAME "amogus"
#define CLASS_NAME "amogus_class"
+#define SLOT_INTERVAL_NS 250000
+
static int major_number;
static struct class* class = NULL;
static struct cdev mycdev;
static message_t* message;
+static struct hrtimer timer;
+static ktime_t interval;
+
static int device_open(struct inode *inode, struct file *file)
{
return 0;
@@ -48,6 +54,11 @@ static const struct file_operations fops = {
.release = device_release
};
+static enum hrtimer_restart timer_callback(struct hrtimer *timer) {
+ hrtimer_forward_now(timer, interval);
+ return HRTIMER_RESTART;
+}
+
static int __init lkm_init(void)
{
dev_t dev;
@@ -93,6 +104,12 @@ static int __init lkm_init(void)
}
printk(KERN_INFO "lkm: device created successfully\n");
+
+ interval = ktime_set(0, SLOT_INTERVAL_NS);
+ hrtimer_init(&timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ timer.function = timer_callback;
+ hrtimer_start(&timer, interval, HRTIMER_MODE_REL);
+
return 0;
}
@@ -104,6 +121,8 @@ static void __exit lkm_exit(void)
class_destroy(class);
unregister_chrdev_region(MKDEV(major_number, 0), 1);
printk(KERN_INFO "lkm: device removed successfully\n");
+
+ hrtimer_cancel(&timer);
}
module_init(lkm_init);
--
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