patch-2.1.15 linux/net/core/dst.c

• Lines: 109
• Date: Thu Dec 12 16:54:23 1996
• Orig file: v2.1.14/linux/net/core/dst.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.14/linux/net/core/dst.c linux/net/core/dst.c
@@ -0,0 +1,108 @@
+/*
+ * net/dst.c	Protocol independent destination cache.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#include <asm/segment.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+#include <net/dst.h>
+
+struct dst_entry * dst_garbage_list;
+atomic_t	dst_total;
+
+static unsigned long dst_gc_timer_expires;
+static unsigned long dst_gc_timer_inc = DST_GC_MAX;
+static void dst_run_gc(unsigned long);
+
+static struct timer_list dst_gc_timer =
+	{ NULL, NULL, DST_GC_MIN, 0L, dst_run_gc };
+
+#if RT_CACHE_DEBUG >= 2
+atomic_t hh_count;
+#endif
+
+static void dst_run_gc(unsigned long dummy)
+{
+	int    delayed = 0;
+	struct dst_entry * dst, **dstp;
+
+	del_timer(&dst_gc_timer);
+	dstp = &dst_garbage_list;
+	while ((dst = *dstp) != NULL) {
+		if (dst->refcnt) {
+			dstp = &dst->next;
+			delayed++;
+			continue;
+		}
+		*dstp = dst->next;
+		dst_destroy(dst);
+	}
+	if (!dst_garbage_list) {
+		dst_gc_timer_inc = DST_GC_MAX;
+		return;
+	}
+	if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX)
+		dst_gc_timer_expires = DST_GC_MAX;
+	dst_gc_timer_inc += DST_GC_INC;
+	dst_gc_timer.expires = jiffies + dst_gc_timer_expires;
+#if RT_CACHE_DEBUG >= 2
+	printk("dst_total: %d/%d/%d %ld\n", dst_total, delayed, hh_count, dst_gc_timer_expires);
+#endif
+	add_timer(&dst_gc_timer);
+}
+
+static int dst_discard(struct sk_buff *skb)
+{
+	kfree_skb(skb, FREE_READ);
+	return 0;
+}
+
+static int dst_blackhole(struct sk_buff *skb)
+{
+	kfree_skb(skb, FREE_WRITE);
+	return 0;
+}
+
+void * dst_alloc(int size, struct dst_ops * ops)
+{
+	struct dst_entry * dst;
+	dst = kmalloc(size, GFP_ATOMIC);
+	if (!dst)
+		return NULL;
+	memset(dst, 0, size);
+	dst->ops = ops;
+	dst->refcnt = 1;
+	dst->lastuse = jiffies;
+	dst->input = dst_discard;
+	dst->output = dst_blackhole;
+	atomic_inc(&dst_total);
+	return dst;
+}
+
+void __dst_free(struct dst_entry * dst)
+{
+	start_bh_atomic();
+	dst->obsolete = 1;
+	dst->next = dst_garbage_list;
+	dst_garbage_list = dst;
+	if (dst_gc_timer_inc > DST_GC_INC) {
+		del_timer(&dst_gc_timer);
+		dst_gc_timer_inc = DST_GC_INC;
+		dst_gc_timer_expires = DST_GC_MIN;
+		dst_gc_timer.expires = jiffies + dst_gc_timer_expires;
+		add_timer(&dst_gc_timer);
+	}
+	end_bh_atomic();
+}