Re: [PATCH] Resetting packet statistics

From: Kris Katterjohn
Date: Tue Nov 29 2005 - 04:28:38 EST


From: David S. Miller
Sent: 11/28/2005 11:02:24 PM
> Or, you can create a new call that says "from now on, do not
> reset statistics on calls using this socket." That's another
> clean, and backwards compatible way, to deal with this
> kind of issue.

I like that one. Here are the updated patches and descriptions:

PACKET_AUTO_STATISTICS (default) lets the kernel reset the stats with each call
of PACKET_STATISTICS and PACKET_MANUAL_STATISTICS won't reset them unless
PACKET_RESET_STATISTICS is called. AUTO and MANUAL can be called multiple times
to change the "state" if necessary.

I didn't check for auto_reset_stats under PACKET_RESET_STATISTICS so it can still
be used to reset the stats while in "auto mode".

Also, just to be sure, is changing PACKET_COPY_THRESH's value in if_packet.h
okay?


Thanks a lot!


--- x/net/packet/af_packet.c 2005-10-27 19:02:08.000000000 -0500
+++ y/net/packet/af_packet.c 2005-11-29 03:02:19.000000000 -0600
@@ -41,6 +41,12 @@
* will simply extend the hardware address
* byte arrays at the end of sockaddr_ll
* and packet_mreq.
+ * Kris Katterjohn : Added setsockopt options:
+ * PACKET_AUTO_STATISTICS,
+ * PACKET_MANUAL_STATISTICS, and
+ * PACKET_RESET_STATISTICS to handle the
+ * zero-ing of packet stats when using
+ * PACKET_STATISTICS. 2005-11-29.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -189,6 +195,7 @@ struct packet_sock {
/* struct sock has to be the first member of packet_sock */
struct sock sk;
struct tpacket_stats stats;
+ int auto_reset_stats;
#ifdef CONFIG_PACKET_MMAP
char * *pg_vec;
unsigned int head;
@@ -1020,6 +1027,7 @@ static int packet_create(struct socket *
po = pkt_sk(sk);
sk->sk_family = PF_PACKET;
po->num = protocol;
+ po->auto_reset_stats = 1;

sk->sk_destruct = packet_sock_destruct;
atomic_inc(&packet_socks_nr);
@@ -1324,6 +1332,7 @@ static int
packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen)
{
struct sock *sk = sock->sk;
+ struct packet_sock *po = pkt_sk(sk);
int ret;

if (level != SOL_PACKET)
@@ -1352,6 +1361,21 @@ packet_setsockopt(struct socket *sock, i
return ret;
}
#endif
+
+ case PACKET_AUTO_STATISTICS:
+ po->auto_reset_stats = 1;
+ return 0;
+
+ case PACKET_MANUAL_STATISTICS:
+ po->auto_reset_stats = 0;
+ return 0;
+
+ case PACKET_RESET_STATISTICS:
+ spin_lock_bh(&sk->sk_receive_queue.lock);
+ memset(&po->stats, 0, sizeof(po->stats));
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
+ return 0;
+
#ifdef CONFIG_PACKET_MMAP
case PACKET_RX_RING:
{
@@ -1406,7 +1430,8 @@ static int packet_getsockopt(struct sock
len = sizeof(struct tpacket_stats);
spin_lock_bh(&sk->sk_receive_queue.lock);
st = po->stats;
- memset(&po->stats, 0, sizeof(st));
+ if (po->auto_reset_stats)
+ memset(&po->stats, 0, sizeof(po->stats));
spin_unlock_bh(&sk->sk_receive_queue.lock);
st.tp_packets += st.tp_drops;


--- x/include/linux/if_packet.h 2005-10-27 19:02:08.000000000 -0500
+++ y/include/linux/if_packet.h 2005-11-29 03:02:19.000000000 -0600
@@ -38,7 +38,10 @@ struct sockaddr_ll
/* Value 4 is still used by obsolete turbo-packet. */
#define PACKET_RX_RING 5
#define PACKET_STATISTICS 6
-#define PACKET_COPY_THRESH 7
+#define PACKET_AUTO_STATISTICS 7
+#define PACKET_MANUAL_STATISTICS 8
+#define PACKET_RESET_STATISTICS 9
+#define PACKET_COPY_THRESH 10

struct tpacket_stats
{


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