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ss statistics fixes

RFC In review Stephen Hemminger 2 participants 8 messages May 2, 2018

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Stephen Hemminger

author
#0 lore raw

cover ss statistics fixes

From: Stephen Hemminger <[email protected]>

The output of the ss -s command has been broken for a long time because of kernel changes (ie since 2.6).

This is an attempt to resolve most of the issues. Still don't like the way it is using slabinfo to get the data but some of this information would be expensive for kernel to account for otherwise.

Stephen Hemminger (5):
ss: make args to get_snmp_int const
ss: make tcp_mem long
ss: use sockstat to get TCP bind ports
ss: don't look for skbuff_head_cache
ss: use correct slab statistics

 misc/ss.c | 39 +++++++++++++++++----------------------
 1 file changed, 17 insertions(+), 22 deletions(-)
Signature · 1 line
2.17.0
author
#1 lore raw

RFC 1/5 ss: make args to get_snmp_int const

These are keys for lookup and should be const.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
misc/ss.c +1 -1
index 3ed7e66962f3..22c76e34f83b 100644
@@ -4539,7 +4539,7 @@ static int handle_follow_request(struct filter *f)
 	return ret;
 }
 
-static int get_snmp_int(char *proto, char *key, int *result)
+static int get_snmp_int(const char *proto, const char *key, int *result)
 {
 	char buf[1024];
 	FILE *fp;
Signature · 1 line
2.17.0
author
#2 lore raw

RFC 2/5 ss: make tcp_mem long

In reply to Stephen Hemminger

The tcp_memory field in /proc/net/sockstat is formatted as a long value by kernel. Change ss to keep this as full value.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
misc/ss.c +2 -2
index 22c76e34f83b..c88a25581755 100644
@@ -4589,7 +4589,7 @@ static int get_snmp_int(const char *proto, const char *key, int *result)
 
 struct ssummary {
 	int socks;
-	int tcp_mem;
+	long tcp_mem;
 	int tcp_total;
 	int tcp_orphans;
 	int tcp_tws;

@@ -4629,7 +4629,7 @@ static void get_sockstat_line(char *line, struct ssummary *s)
 	else if (strcmp(id, "FRAG6:") == 0)
 		sscanf(rem, "%*s%d%*s%d", &s->frag6, &s->frag6_mem);
 	else if (strcmp(id, "TCP:") == 0)
-		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%d",
+		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%ld",
 		       &s->tcp4_hashed,
 		       &s->tcp_orphans, &s->tcp_tws, &s->tcp_total, &s->tcp_mem);
 }
Signature · 1 line
2.17.0
#3 lore raw

Re: [RFC iproute2-next 2/5] ss: make tcp_mem long

Quoted 23 lines · Stephen Hemminger

The tcp_memory field in /proc/net/sockstat is formatted as a long value by kernel. Change ss to keep this as full value.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
misc/ss.c +1 -1
index 22c76e34f83b..c88a25581755 100644
@@ -4589,7 +4589,7 @@ static int get_snmp_int(const char *proto, const char *key, int *result)
 
 struct ssummary {
 	int socks;
-	int tcp_mem;
+	long tcp_mem;
 	int tcp_total;
 	int tcp_orphans;
 	int tcp_tws;

misc/ss.c static void get_sockstat_line(char *line, struct ssummary *s) · line 4635

Quoted 8 lines
misc/ss.c +1 -1
@@ -4629,7 +4629,7 @@ static void get_sockstat_line(char *line, struct ssummary *s)
 	else if (strcmp(id, "FRAG6:") == 0)
 		sscanf(rem, "%*s%d%*s%d", &s->frag6, &s->frag6_mem);
 	else if (strcmp(id, "TCP:") == 0)
-		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%d",
+		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%ld",
 		       &s->tcp4_hashed,
 		       &s->tcp_orphans, &s->tcp_tws, &s->tcp_total, &s->tcp_mem);
 }

Hi Stephen

It seems nothing uses yet the value ?

Also, do we care of iproute2 being compiled in 32bit mode, but eventually running on 64bit kernel ?

author
#4 lore raw

Re: [RFC iproute2-next 2/5] ss: make tcp_mem long

Quoted 35 lines · On Wed, 2 May 2018 14:08:53 -0700 Eric Dumazet <[email protected]> wrote:
Quoted 23 lines · Stephen Hemminger

The tcp_memory field in /proc/net/sockstat is formatted as a long value by kernel. Change ss to keep this as full value.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
misc/ss.c +1 -1
index 22c76e34f83b..c88a25581755 100644
@@ -4589,7 +4589,7 @@ static int get_snmp_int(const char *proto, const char *key, int *result)
 
 struct ssummary {
 	int socks;
-	int tcp_mem;
+	long tcp_mem;
 	int tcp_total;
 	int tcp_orphans;
 	int tcp_tws;

misc/ss.c static void get_sockstat_line(char *line, struct ssummary *s) · line 4635

Quoted 8 lines
misc/ss.c +1 -1
@@ -4629,7 +4629,7 @@ static void get_sockstat_line(char *line, struct ssummary *s)
 	else if (strcmp(id, "FRAG6:") == 0)
 		sscanf(rem, "%*s%d%*s%d", &s->frag6, &s->frag6_mem);
 	else if (strcmp(id, "TCP:") == 0)
-		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%d",
+		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%ld",
 		       &s->tcp4_hashed,
 		       &s->tcp_orphans, &s->tcp_tws, &s->tcp_total, &s->tcp_mem);
 }

Hi Stephen

Quoted 1 line

It seems nothing uses yet the value ?

Yup. let's just drop it from the scan

author
#5 lore raw

RFC 3/5 ss: use sockstat to get TCP bind ports

In reply to Stephen Hemminger

From: Stephen Hemminger <[email protected]>

Using slabinfo to try and get the number of bind_buckets no longer works because of slab cache merging. Instead use proposed enhancment of /proc/net/sockstat to get the same data.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)
misc/ss.c +4 -6
index c88a25581755..4f76999c0fee 100644
@@ -732,7 +732,6 @@ next:
 
 struct slabstat {
 	int socks;
-	int tcp_ports;
 	int tcp_tws;
 	int tcp_syns;
 	int skbs;

@@ -748,7 +747,6 @@ static int get_slabstat(struct slabstat *s)
 	static int slabstat_valid;
 	static const char * const slabstat_ids[] = {
 		"sock",
-		"tcp_bind_bucket",
 		"tcp_tw_bucket",
 		"tcp_open_request",
 		"skbuff_head_cache",

@@ -4594,6 +4592,7 @@ struct ssummary {
 	int tcp_orphans;
 	int tcp_tws;
 	int tcp4_hashed;
+	int tcp_ports;
 	int udp4;
 	int raw4;
 	int frag4;

@@ -4629,9 +4628,9 @@ static void get_sockstat_line(char *line, struct ssummary *s)
 	else if (strcmp(id, "FRAG6:") == 0)
 		sscanf(rem, "%*s%d%*s%d", &s->frag6, &s->frag6_mem);
 	else if (strcmp(id, "TCP:") == 0)
-		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%ld",
+		sscanf(rem, "%*s%d%*s%d%*s%d%*s%d%*s%ld%*s%d",
 		       &s->tcp4_hashed,
-		       &s->tcp_orphans, &s->tcp_tws, &s->tcp_total, &s->tcp_mem);
+		       &s->tcp_orphans, &s->tcp_tws, &s->tcp_total, &s->tcp_mem, &s->tcp_ports);
 }
 
 static int get_sockstat(struct ssummary *s)

@@ -4676,8 +4675,7 @@ static int print_summary(void)
 	       s.tcp_total - (s.tcp4_hashed+s.tcp6_hashed-s.tcp_tws),
 	       s.tcp_orphans,
 	       slabstat.tcp_syns,
-	       s.tcp_tws, slabstat.tcp_tws,
-	       slabstat.tcp_ports
+	       s.tcp_tws, slabstat.tcp_tws, s.tcp_ports
 	       );
 
 	printf("\n");
Signature · 1 line
2.17.0
author
#6 lore raw

RFC 4/5 ss: don't look for skbuff_head_cache

In reply to Stephen Hemminger

From: Stephen Hemminger <[email protected]>

Not used in current code.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 2 --
 1 file changed, 2 deletions(-)
misc/ss.c +0 -2
index 4f76999c0fee..97304cd8abfc 100644
@@ -734,7 +734,6 @@ struct slabstat {
 	int socks;
 	int tcp_tws;
 	int tcp_syns;
-	int skbs;
 };
 
 static struct slabstat slabstat;

@@ -749,7 +748,6 @@ static int get_slabstat(struct slabstat *s)
 		"sock",
 		"tcp_tw_bucket",
 		"tcp_open_request",
-		"skbuff_head_cache",
 	};
 
 	if (slabstat_valid)
Signature · 1 line
2.17.0
author
#7 lore raw

RFC 5/5 ss: use correct slab statistics

In reply to Stephen Hemminger

From: Stephen Hemminger <[email protected]>

The slabinfo names changed years ago, and ss statistics were broken. This changes to use current slab names and handle TCP IPv6.

Signed-off-by Stephen Hemminger <[email protected]>
---
 misc/ss.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)
misc/ss.c +11 -12
index 97304cd8abfc..66c767cc415b 100644
@@ -742,12 +742,12 @@ static int get_slabstat(struct slabstat *s)
 {
 	char buf[256];
 	FILE *fp;
-	int cnt;
+	int *stats = (int *) s;
 	static int slabstat_valid;
 	static const char * const slabstat_ids[] = {
-		"sock",
-		"tcp_tw_bucket",
-		"tcp_open_request",
+		"sock_inode_cache",
+		"tw_sock_TCP",
+		"request_sock_TCP",
 	};
 
 	if (slabstat_valid)

@@ -759,24 +759,23 @@ static int get_slabstat(struct slabstat *s)
 	if (!fp)
 		return -1;
 
-	cnt = sizeof(*s)/sizeof(int);
-
 	if (!fgets(buf, sizeof(buf), fp)) {
 		fclose(fp);
 		return -1;
 	}
+
 	while (fgets(buf, sizeof(buf), fp) != NULL) {
-		int i;
+		int i, v;
 
 		for (i = 0; i < ARRAY_SIZE(slabstat_ids); i++) {
-			if (memcmp(buf, slabstat_ids[i], strlen(slabstat_ids[i])) == 0) {
-				sscanf(buf, "%*s%d", ((int *)s) + i);
-				cnt--;
+			if (memcmp(buf, slabstat_ids[i], strlen(slabstat_ids[i])) != 0)
+				continue;
+
+			if (sscanf(buf, "%*s%d", &v) == 1) {
+				stats[i] += v;
 				break;
 			}
 		}
-		if (cnt <= 0)
-			break;
 	}
 
 	slabstat_valid = 1;
Signature · 1 line
2.17.0