Show the number of times we block waiting for mbufs.

Machines can stall out because mbufs are low, however sometimes we won't
see "requests denied", instead we see user land processes or kernel threads
blocking waiting for mbufs because they set M_WAIT.  These consumers do not
see errors, only stalling.

Unfortunately until now, netstat did not export this information
so you could have experienced an mbuf shortage and have no way of
seeing it unless you happen to run netstat at the exact time of the
shortage and see "in use" = "max".

By exporting the number of times processes are blocked, we can
effectively see how often non-interrupt context threads are effectively
"denied".

MFC after: 2 weeks

1 files changed, 18 insertions, 4 deletions

diff --git a/usr.bin/netstat/mbuf.c b/usr.bin/netstat/mbuf.c
index 7f65701..401a03c 100644
--- a/usr.bin/netstat/mbuf.c
+++ b/usr.bin/netstat/mbuf.c
@@ -67,16 +67,18 @@ mbpr(void *kvmd, u_long mbaddr)
 	struct memory_type_list *mtlp;
 	struct memory_type *mtp;
 	uintmax_t mbuf_count, mbuf_bytes, mbuf_free, mbuf_failures, mbuf_size;
+	uintmax_t mbuf_sleeps;
 	uintmax_t cluster_count, cluster_bytes, cluster_limit, cluster_free;
-	uintmax_t cluster_failures, cluster_size;
+	uintmax_t cluster_failures, cluster_size, cluster_sleeps;
 	uintmax_t packet_count, packet_bytes, packet_free, packet_failures;
+	uintmax_t packet_sleeps;
 	uintmax_t tag_count, tag_bytes;
 	uintmax_t jumbop_count, jumbop_bytes, jumbop_limit, jumbop_free;
-	uintmax_t jumbop_failures, jumbop_size;
+	uintmax_t jumbop_failures, jumbop_sleeps, jumbop_size;
 	uintmax_t jumbo9_count, jumbo9_bytes, jumbo9_limit, jumbo9_free;
-	uintmax_t jumbo9_failures, jumbo9_size;
+	uintmax_t jumbo9_failures, jumbo9_sleeps, jumbo9_size;
 	uintmax_t jumbo16_count, jumbo16_bytes, jumbo16_limit, jumbo16_free;
-	uintmax_t jumbo16_failures, jumbo16_size;
+	uintmax_t jumbo16_failures, jumbo16_sleeps, jumbo16_size;
 	uintmax_t bytes_inuse, bytes_incache, bytes_total;
 	int nsfbufs, nsfbufspeak, nsfbufsused;
 	struct mbstat mbstat;
@@ -121,6 +123,7 @@ mbpr(void *kvmd, u_long mbaddr)
 	mbuf_bytes = memstat_get_bytes(mtp);
 	mbuf_free = memstat_get_free(mtp);
 	mbuf_failures = memstat_get_failures(mtp);
+	mbuf_sleeps = memstat_get_sleeps(mtp);
 	mbuf_size = memstat_get_size(mtp);
 
 	mtp = memstat_mtl_find(mtlp, ALLOCATOR_UMA, MBUF_PACKET_MEM_NAME);
@@ -132,6 +135,7 @@ mbpr(void *kvmd, u_long mbaddr)
 	packet_count = memstat_get_count(mtp);
 	packet_bytes = memstat_get_bytes(mtp);
 	packet_free = memstat_get_free(mtp);
+	packet_sleeps = memstat_get_sleeps(mtp);
 	packet_failures = memstat_get_failures(mtp);
 
 	mtp = memstat_mtl_find(mtlp, ALLOCATOR_UMA, MBUF_CLUSTER_MEM_NAME);
@@ -145,6 +149,7 @@ mbpr(void *kvmd, u_long mbaddr)
 	cluster_limit = memstat_get_countlimit(mtp);
 	cluster_free = memstat_get_free(mtp);
 	cluster_failures = memstat_get_failures(mtp);
+	cluster_sleeps = memstat_get_sleeps(mtp);
 	cluster_size = memstat_get_size(mtp);
 
 	mtp = memstat_mtl_find(mtlp, ALLOCATOR_MALLOC, MBUF_TAG_MEM_NAME);
@@ -167,6 +172,7 @@ mbpr(void *kvmd, u_long mbaddr)
 	jumbop_limit = memstat_get_countlimit(mtp);
 	jumbop_free = memstat_get_free(mtp);
 	jumbop_failures = memstat_get_failures(mtp);
+	jumbop_sleeps = memstat_get_sleeps(mtp);
 	jumbop_size = memstat_get_size(mtp);
 
 	mtp = memstat_mtl_find(mtlp, ALLOCATOR_UMA, MBUF_JUMBO9_MEM_NAME);
@@ -180,6 +186,7 @@ mbpr(void *kvmd, u_long mbaddr)
 	jumbo9_limit = memstat_get_countlimit(mtp);
 	jumbo9_free = memstat_get_free(mtp);
 	jumbo9_failures = memstat_get_failures(mtp);
+	jumbo9_sleeps = memstat_get_sleeps(mtp);
 	jumbo9_size = memstat_get_size(mtp);
 
 	mtp = memstat_mtl_find(mtlp, ALLOCATOR_UMA, MBUF_JUMBO16_MEM_NAME);
@@ -193,6 +200,7 @@ mbpr(void *kvmd, u_long mbaddr)
 	jumbo16_limit = memstat_get_countlimit(mtp);
 	jumbo16_free = memstat_get_free(mtp);
 	jumbo16_failures = memstat_get_failures(mtp);
+	jumbo16_sleeps = memstat_get_sleeps(mtp);
 	jumbo16_size = memstat_get_size(mtp);
 
 	printf("%ju/%ju/%ju mbufs in use (current/cache/total)\n",
@@ -279,7 +287,13 @@ mbpr(void *kvmd, u_long mbaddr)
 	printf("%ju/%ju/%ju requests for mbufs denied (mbufs/clusters/"
 	    "mbuf+clusters)\n", mbuf_failures, cluster_failures,
 	    packet_failures);
+	printf("%ju/%ju/%ju requests for mbufs delayed (mbufs/clusters/"
+	    "mbuf+clusters)\n", mbuf_sleeps, cluster_sleeps,
+	    packet_sleeps);
 
+	printf("%ju/%ju/%ju requests for jumbo clusters delayed "
+	    "(%juk/9k/16k)\n", jumbop_sleeps, jumbo9_sleeps,
+	    jumbo16_sleeps, jumbop_size / 1024);
 	printf("%ju/%ju/%ju requests for jumbo clusters denied "
 	    "(%juk/9k/16k)\n", jumbop_failures, jumbo9_failures,
 	    jumbo16_failures, jumbop_size / 1024);