RDS: Info and stats

RDS currently generates a lot of stats that are accessible via
the rds-info utility. This code implements the support for this.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 148 insertions, 0 deletions

diff --git a/net/rds/stats.c b/net/rds/stats.c
new file mode 100644
index 000000000000..637146893cf3
--- /dev/null
+++ b/net/rds/stats.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2006 Oracle.  All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+#include <linux/percpu.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+#include "rds.h"
+
+DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats);
+
+/* :.,$s/unsigned long\>.*\<s_\(.*\);/"\1",/g */
+
+static char *rds_stat_names[] = {
+        "conn_reset",
+        "recv_drop_bad_checksum",
+        "recv_drop_old_seq",
+        "recv_drop_no_sock",
+        "recv_drop_dead_sock",
+        "recv_deliver_raced",
+        "recv_delivered",
+        "recv_queued",
+        "recv_immediate_retry",
+        "recv_delayed_retry",
+        "recv_ack_required",
+        "recv_rdma_bytes",
+        "recv_ping",
+        "send_queue_empty",
+        "send_queue_full",
+        "send_sem_contention",
+        "send_sem_queue_raced",
+        "send_immediate_retry",
+        "send_delayed_retry",
+        "send_drop_acked",
+        "send_ack_required",
+        "send_queued",
+        "send_rdma",
+        "send_rdma_bytes",
+        "send_pong",
+        "page_remainder_hit",
+        "page_remainder_miss",
+        "copy_to_user",
+        "copy_from_user",
+        "cong_update_queued",
+        "cong_update_received",
+        "cong_send_error",
+        "cong_send_blocked",
+};
+
+void rds_stats_info_copy(struct rds_info_iterator *iter,
+                         uint64_t *values, char **names, size_t nr)
+{
+        struct rds_info_counter ctr;
+        size_t i;
+
+        for (i = 0; i < nr; i++) {
+                BUG_ON(strlen(names[i]) >= sizeof(ctr.name));
+                strncpy(ctr.name, names[i], sizeof(ctr.name) - 1);
+                ctr.value = values[i];
+
+                rds_info_copy(iter, &ctr, sizeof(ctr));
+        }
+}
+
+/*
+ * This gives global counters across all the transports.  The strings
+ * are copied in so that the tool doesn't need knowledge of the specific
+ * stats that we're exporting.  Some are pretty implementation dependent
+ * and may change over time.  That doesn't stop them from being useful.
+ *
+ * This is the only function in the chain that knows about the byte granular
+ * length in userspace.  It converts it to number of stat entries that the
+ * rest of the functions operate in.
+ */
+static void rds_stats_info(struct socket *sock, unsigned int len,
+                           struct rds_info_iterator *iter,
+                           struct rds_info_lengths *lens)
+{
+        struct rds_statistics stats = {0, };
+        uint64_t *src;
+        uint64_t *sum;
+        size_t i;
+        int cpu;
+        unsigned int avail;
+
+        avail = len / sizeof(struct rds_info_counter);
+
+        if (avail < ARRAY_SIZE(rds_stat_names)) {
+                avail = 0;
+                goto trans;
+        }
+
+        for_each_online_cpu(cpu) {
+                src = (uint64_t *)&(per_cpu(rds_stats, cpu));
+                sum = (uint64_t *)&stats;
+                for (i = 0; i < sizeof(stats) / sizeof(uint64_t); i++)
+                        *(sum++) += *(src++);
+        }
+
+        rds_stats_info_copy(iter, (uint64_t *)&stats, rds_stat_names,
+                            ARRAY_SIZE(rds_stat_names));
+        avail -= ARRAY_SIZE(rds_stat_names);
+
+trans:
+        lens->each = sizeof(struct rds_info_counter);
+        lens->nr = rds_trans_stats_info_copy(iter, avail) +
+                   ARRAY_SIZE(rds_stat_names);
+}
+
+void rds_stats_exit(void)
+{
+        rds_info_deregister_func(RDS_INFO_COUNTERS, rds_stats_info);
+}
+
+int __init rds_stats_init(void)
+{
+        rds_info_register_func(RDS_INFO_COUNTERS, rds_stats_info);
+        return 0;
+}