Add "profiling" code to CCID2. It is now possible to monitor the state of CCID2
from user-land. Currently, the information which is available is:
* cwnd
* pipe
* srtt
* packets / second.
If you are interested in a userland tool for collecting such data let me know.
Signed-off-by: Andrea Bittau <a.bittau@xxxxxxxxxxxx>
---
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index b6f6681..50da0f5 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -35,6 +35,7 @@ #include "../dccp.h"
#include "ccid2.h"
static int ccid2_debug;
+static int ccid2_profile;
#ifdef CONFIG_IP_DCCP_CCID2_DEBUG
#define ccid2_pr_debug(format, a...) \
@@ -90,6 +91,131 @@ #else
#define ccid2_hc_tx_check_sanity(hctx) do {} while (0)
#endif
+static int ccid2_pv_init(struct ccid2_profvar *pv, int type, int count)
+{
+ pv->ccid2pv_size = count;
+ pv->ccid2pv_pos = 0;
+ pv->ccid2pv_overflow = 0;
+ pv->ccid2pv_type = type;
+
+ pv->ccid2pv_data = kmalloc(sizeof(*pv->ccid2pv_data) * pv->ccid2pv_size,
+ gfp_any());
+ if (!pv->ccid2pv_data)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void ccid2_pv_del(struct ccid2_profvar *pv)
+{
+ if (pv->ccid2pv_data) {
+ kfree(pv->ccid2pv_data);
+ pv->ccid2pv_data = 0;
+ }
+}
+
+static u64 ccid2_profile_time(void)
+{
+#if defined(__i386__)
+ u32 l, h;
+ u64 t;
+
+ rdtsc(l, h);
+
+ t = h;
+ t <<= 32;
+ t |= l;
+
+ return t;
+#else
+ return jiffies;
+#endif
+}
+
+static void ccid2_pv_add(struct ccid2_profvar *pv, long val)
+{
+ struct ccid2_profdata *pd = &pv->ccid2pv_data[pv->ccid2pv_pos];
+
+ pd->ccid2pd_time = ccid2_profile_time();
+ pd->ccid2pd_val = val;
+
+ pv->ccid2pv_pos++;
+ if (pv->ccid2pv_pos >= pv->ccid2pv_size) {
+ pv->ccid2pv_pos = 0;
+
+ /* strictly speaking, there is no overflow until the next write
+ * happens, but for ease of programming, we set the bit here.
+ */
+ pv->ccid2pv_overflow = 1;
+ }
+}
+
+static int ccid2_pv_copy_to_user(struct ccid2_profvar *pv, void __user *buf,
+ int copylen)
+{
+ int totlen;
+ int rc;
+ unsigned char over = pv->ccid2pv_overflow;
+ unsigned char __user *bufp = buf;
+ struct ccid2_pdhdr hdr;
+
+ totlen = sizeof(hdr);
+
+ /* If we overflowed, the whole buffer has new data */
+ if (over)
+ totlen += pv->ccid2pv_size * sizeof(*pv->ccid2pv_data);
+ else
+ totlen += pv->ccid2pv_pos * sizeof(*pv->ccid2pv_data);
+
+ if (copylen > totlen)
+ copylen = totlen;
+
+ if (copylen < sizeof(hdr))
+ return -EINVAL;
+ totlen = copylen;
+
+ /* header */
+ copylen -= sizeof(hdr);
+ hdr.ccid2pdh_overflow = over;
+ hdr.ccid2pdh_type = pv->ccid2pv_type;
+ hdr.ccid2pdh_len = copylen;
+ if ((rc = copy_to_user(bufp, &hdr, sizeof(hdr))))
+ return rc;
+ bufp += sizeof(hdr);
+
+ /* copy data */
+ if (over) {
+ struct ccid2_profdata *pd;
+ int rem = pv->ccid2pv_size - pv->ccid2pv_pos;
+
+ /* copy tail of buffer first */
+ pd = &pv->ccid2pv_data[pv->ccid2pv_pos];
+ while (rem--) {
+ if (copylen < sizeof(*pd))
+ break;
+
+ rc = copy_to_user(bufp, pd, sizeof(*pd));
+ if (rc)
+ return rc;
+
+ bufp += sizeof(*pd);
+ copylen -= sizeof(*pd);
+ pd++;
+ }
+ }
+
+ rc = copy_to_user(bufp, pv->ccid2pv_data, copylen);
+ if (rc)
+ return rc;
+
+ /* reset buffer */
+ /* XXX assumes that the user supplied a buffer large enough */
+ pv->ccid2pv_overflow = 0;
+ pv->ccid2pv_pos = 0;
+
+ return totlen;
+}
+
static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num)
{
struct ccid2_seq *seqp;
@@ -187,6 +313,13 @@ static void ccid2_change_l_ack_ratio(str
dp->dccps_l_ack_ratio = val;
}
+static inline void ccid2_profile_var(struct ccid2_hc_tx_sock *hctx, int var,
+ long val)
+{
+ if (ccid2_profile)
+ ccid2_pv_add(&hctx->ccid2hctx_profile.ccid2txp_vars[var], val);
+}
+
static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, int val)
{
if (val == 0)
@@ -197,6 +330,7 @@ static void ccid2_change_cwnd(struct cci
BUG_ON(val < 1);
hctx->ccid2hctx_cwnd = val;
+ ccid2_profile_var(hctx, CCID2_PROF_CWND, hctx->ccid2hctx_cwnd);
}
static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val)
@@ -207,10 +341,17 @@ static void ccid2_change_srtt(struct cci
return;
hctx->ccid2hctx_srtt = val;
+ ccid2_profile_var(hctx, CCID2_PROF_SRTT, hctx->ccid2hctx_srtt);
}
static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val)
{
+ /* Don't log all pipe changes---too much stuff */
+ if (abs(hctx->ccid2hctx_profile.ccid2txp_lpipe - val) > 2) {
+ ccid2_profile_var(hctx, CCID2_PROF_PIPE, val);
+ hctx->ccid2hctx_profile.ccid2txp_lpipe = val;
+ }
+
hctx->ccid2hctx_pipe = val;
}
@@ -287,6 +428,22 @@ static void ccid2_hc_tx_packet_sent(stru
ccid2_hc_tx_check_sanity(hctx);
+ if (ccid2_profile) {
+ unsigned long diff;
+
+ hctx->ccid2hctx_profile.ccid2txp_packets++;
+ diff = (long)jiffies -
+ (long)hctx->ccid2hctx_profile.ccid2txp_packets_last;
+
+ if (diff >= HZ) {
+ ccid2_profile_var(hctx, CCID2_PROF_PS,
+ (hctx->ccid2hctx_profile.
+ ccid2txp_packets/diff)*HZ);
+ hctx->ccid2hctx_profile.ccid2txp_packets = 0;
+ hctx->ccid2hctx_profile.ccid2txp_packets_last = jiffies;
+ }
+ }
+
BUG_ON(!hctx->ccid2hctx_sendwait);
hctx->ccid2hctx_sendwait = 0;
ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe+1);
@@ -754,6 +911,26 @@ static int ccid2_hc_tx_init(struct ccid
{
struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid);
+ if (ccid2_profile) {
+ int rc;
+ int i;
+
+ for (i = 0; i < CCID2_PROF_LAST; i++) {
+ rc = ccid2_pv_init(&hctx->ccid2hctx_profile.
+ ccid2txp_vars[i], i, 6000);
+ if (rc) {
+ while (--i > 0)
+ ccid2_pv_del(&hctx->ccid2hctx_profile.
+ ccid2txp_vars[i]);
+ return rc;
+ }
+ }
+
+ hctx->ccid2hctx_profile.ccid2txp_lpipe = 0;
+ hctx->ccid2hctx_profile.ccid2txp_packets = 0;
+ hctx->ccid2hctx_profile.ccid2txp_packets_last = jiffies;
+ }
+
ccid2_change_cwnd(hctx, 1);
hctx->ccid2hctx_ssthresh = 666666; /* "infinite" [for a while] */
hctx->ccid2hctx_numdupack = 3;
@@ -789,6 +966,13 @@ static void ccid2_hc_tx_exit(struct sock
for (i = 0; i < hctx->ccid2hctx_seqbufc; i++)
kfree(hctx->ccid2hctx_seqbuf[i]);
hctx->ccid2hctx_seqbufc = 0;
+
+ if (ccid2_profile) {
+ int i;
+
+ for (i = 0; i < CCID2_PROF_LAST; i++)
+ ccid2_pv_del(&hctx->ccid2hctx_profile.ccid2txp_vars[i]);
+ }
}
static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
@@ -808,6 +992,58 @@ static void ccid2_hc_rx_packet_recv(stru
}
}
+static int ccid2_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
+ u32 __user *optval, int __user *optlen)
+{
+ return -ENOPROTOOPT;
+}
+
+static int ccid2_hc_tx_profile(struct sock *sk, u32 __user *optval,
+ int __user *optlen)
+{
+ struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+ int rem;
+ int rc;
+ int copied = 0;
+ int i;
+ unsigned char __user *buf = (unsigned char *) optval;
+
+ rc = get_user(rem, optlen);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < CCID2_PROF_LAST; i++) {
+ rc = ccid2_pv_copy_to_user(&hctx->ccid2hctx_profile.
+ ccid2txp_vars[i], buf, rem);
+ if (rc < 0)
+ return rc;
+
+ rem -= rc;
+ copied += rc;
+ buf += rc;
+ if (rem <= 0)
+ break;
+ }
+
+ rc = put_user(copied, optlen);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+static int ccid2_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
+ u32 __user *optval, int __user *optlen)
+{
+ switch (optname) {
+ case DCCP_SOCKOPT_CCID_TX_INFO:
+ if (ccid2_profile)
+ return ccid2_hc_tx_profile(sk, optval, optlen);
+ }
+
+ return -ENOPROTOOPT;
+}
+
static struct ccid_operations ccid2 = {
.ccid_id = 2,
.ccid_name = "ccid2",
@@ -820,11 +1056,16 @@ static struct ccid_operations ccid2 = {
.ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv,
.ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock),
.ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv,
+ .ccid_hc_rx_getsockopt = ccid2_hc_rx_getsockopt,
+ .ccid_hc_tx_getsockopt = ccid2_hc_tx_getsockopt,
};
module_param(ccid2_debug, int, 0444);
MODULE_PARM_DESC(ccid2_debug, "Enable debug messages");
+module_param(ccid2_profile, int, 0444);
+MODULE_PARM_DESC(ccid2_profile, "Enable profiling");
+
static __init int ccid2_module_init(void)
{
return ccid_register(&ccid2);
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 3bc4b76..d208657 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -35,6 +35,41 @@ struct ccid2_seq {
struct ccid2_seq *ccid2s_next;
};
+struct ccid2_pdhdr {
+ u8 ccid2pdh_overflow;
+ u8 ccid2pdh_type;
+ int ccid2pdh_len;
+};
+
+struct ccid2_profdata {
+ u64 ccid2pd_time;
+ long ccid2pd_val;
+};
+
+enum {
+ CCID2_PROF_CWND = 0,
+ CCID2_PROF_SRTT,
+ CCID2_PROF_PIPE,
+ CCID2_PROF_PS,
+
+ CCID2_PROF_LAST
+};
+
+struct ccid2_profvar {
+ struct ccid2_profdata *ccid2pv_data;
+ int ccid2pv_size;
+ int ccid2pv_pos;
+ int ccid2pv_overflow;
+ int ccid2pv_type;
+};
+
+struct ccid2_txprofile {
+ struct ccid2_profvar ccid2txp_vars[CCID2_PROF_LAST];
+ long ccid2txp_lpipe;
+ long ccid2txp_packets;
+ unsigned long ccid2txp_packets_last;
+};
+
#define CCID2_SEQBUF_LEN 256
#define CCID2_SEQBUF_MAX 128
@@ -72,6 +107,7 @@ struct ccid2_hc_tx_sock {
int ccid2hctx_rpdupack;
int ccid2hctx_sendwait;
unsigned long ccid2hctx_last_cong;
+ struct ccid2_txprofile ccid2hctx_profile;
};
struct ccid2_hc_rx_sock {
-
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