RDMA/rtrs: client: statistics functions

This introduces set of functions used on client side to account statistics
of RDMA data sent/received, amount of IOs inflight, latency, cpu
migrations, etc.  Almost all statistics are collected using percpu
variables.

Link: https://lore.kernel.org/r/20200511135131.27580-8-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
new file mode 100644 (file)
index 0000000..26bbe5d
--- /dev/null
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Transport Layer
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include "rtrs-clt.h"
+
+void rtrs_clt_update_wc_stats(struct rtrs_clt_con *con)
+{
+       struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+       struct rtrs_clt_stats *stats = sess->stats;
+       struct rtrs_clt_stats_pcpu *s;
+       int cpu;
+
+       cpu = raw_smp_processor_id();
+       s = this_cpu_ptr(stats->pcpu_stats);
+       if (unlikely(con->cpu != cpu)) {
+               s->cpu_migr.to++;
+
+               /* Careful here, override s pointer */
+               s = per_cpu_ptr(stats->pcpu_stats, con->cpu);
+               atomic_inc(&s->cpu_migr.from);
+       }
+}
+
+void rtrs_clt_inc_failover_cnt(struct rtrs_clt_stats *stats)
+{
+       struct rtrs_clt_stats_pcpu *s;
+
+       s = this_cpu_ptr(stats->pcpu_stats);
+       s->rdma.failover_cnt++;
+}
+
+int rtrs_clt_stats_migration_cnt_to_str(struct rtrs_clt_stats *stats,
+                                        char *buf, size_t len)
+{
+       struct rtrs_clt_stats_pcpu *s;
+
+       size_t used;
+       int cpu;
+
+       used = scnprintf(buf, len, "    ");
+       for_each_possible_cpu(cpu)
+               used += scnprintf(buf + used, len - used, " CPU%u", cpu);
+
+       used += scnprintf(buf + used, len - used, "\nfrom:");
+       for_each_possible_cpu(cpu) {
+               s = per_cpu_ptr(stats->pcpu_stats, cpu);
+               used += scnprintf(buf + used, len - used, " %d",
+                                 atomic_read(&s->cpu_migr.from));
+       }
+
+       used += scnprintf(buf + used, len - used, "\nto  :");
+       for_each_possible_cpu(cpu) {
+               s = per_cpu_ptr(stats->pcpu_stats, cpu);
+               used += scnprintf(buf + used, len - used, " %d",
+                                 s->cpu_migr.to);
+       }
+       used += scnprintf(buf + used, len - used, "\n");
+
+       return used;
+}
+
+int rtrs_clt_stats_reconnects_to_str(struct rtrs_clt_stats *stats, char *buf,
+                                     size_t len)
+{
+       return scnprintf(buf, len, "%d %d\n",
+                        stats->reconnects.successful_cnt,
+                        stats->reconnects.fail_cnt);
+}
+
+ssize_t rtrs_clt_stats_rdma_to_str(struct rtrs_clt_stats *stats,
+                                   char *page, size_t len)
+{
+       struct rtrs_clt_stats_rdma sum;
+       struct rtrs_clt_stats_rdma *r;
+       int cpu;
+
+       memset(&sum, 0, sizeof(sum));
+
+       for_each_possible_cpu(cpu) {
+               r = &per_cpu_ptr(stats->pcpu_stats, cpu)->rdma;
+
+               sum.dir[READ].cnt         += r->dir[READ].cnt;
+               sum.dir[READ].size_total  += r->dir[READ].size_total;
+               sum.dir[WRITE].cnt        += r->dir[WRITE].cnt;
+               sum.dir[WRITE].size_total += r->dir[WRITE].size_total;
+               sum.failover_cnt          += r->failover_cnt;
+       }
+
+       return scnprintf(page, len, "%llu %llu %llu %llu %u %llu\n",
+                        sum.dir[READ].cnt, sum.dir[READ].size_total,
+                        sum.dir[WRITE].cnt, sum.dir[WRITE].size_total,
+                        atomic_read(&stats->inflight), sum.failover_cnt);
+}
+
+ssize_t rtrs_clt_reset_all_help(struct rtrs_clt_stats *s,
+                                char *page, size_t len)
+{
+       return scnprintf(page, len, "echo 1 to reset all statistics\n");
+}
+
+int rtrs_clt_reset_rdma_stats(struct rtrs_clt_stats *stats, bool enable)
+{
+       struct rtrs_clt_stats_pcpu *s;
+       int cpu;
+
+       if (!enable)
+               return -EINVAL;
+
+       for_each_possible_cpu(cpu) {
+               s = per_cpu_ptr(stats->pcpu_stats, cpu);
+               memset(&s->rdma, 0, sizeof(s->rdma));
+       }
+
+       return 0;
+}
+
+int rtrs_clt_reset_cpu_migr_stats(struct rtrs_clt_stats *stats, bool enable)
+{
+       struct rtrs_clt_stats_pcpu *s;
+       int cpu;
+
+       if (!enable)
+               return -EINVAL;
+
+       for_each_possible_cpu(cpu) {
+               s = per_cpu_ptr(stats->pcpu_stats, cpu);
+               memset(&s->cpu_migr, 0, sizeof(s->cpu_migr));
+       }
+
+       return 0;
+}
+
+int rtrs_clt_reset_reconnects_stat(struct rtrs_clt_stats *stats, bool enable)
+{
+       if (!enable)
+               return -EINVAL;
+
+       memset(&stats->reconnects, 0, sizeof(stats->reconnects));
+
+       return 0;
+}
+
+int rtrs_clt_reset_all_stats(struct rtrs_clt_stats *s, bool enable)
+{
+       if (enable) {
+               rtrs_clt_reset_rdma_stats(s, enable);
+               rtrs_clt_reset_cpu_migr_stats(s, enable);
+               rtrs_clt_reset_reconnects_stat(s, enable);
+               atomic_set(&s->inflight, 0);
+               return 0;
+       }
+
+       return -EINVAL;
+}
+
+static inline void rtrs_clt_update_rdma_stats(struct rtrs_clt_stats *stats,
+                                              size_t size, int d)
+{
+       struct rtrs_clt_stats_pcpu *s;
+
+       s = this_cpu_ptr(stats->pcpu_stats);
+       s->rdma.dir[d].cnt++;
+       s->rdma.dir[d].size_total += size;
+}
+
+void rtrs_clt_update_all_stats(struct rtrs_clt_io_req *req, int dir)
+{
+       struct rtrs_clt_con *con = req->con;
+       struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
+       struct rtrs_clt_stats *stats = sess->stats;
+       unsigned int len;
+
+       len = req->usr_len + req->data_len;
+       rtrs_clt_update_rdma_stats(stats, len, dir);
+       if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
+               atomic_inc(&stats->inflight);
+}
+
+int rtrs_clt_init_stats(struct rtrs_clt_stats *stats)
+{
+       stats->pcpu_stats = alloc_percpu(typeof(*stats->pcpu_stats));
+       if (!stats->pcpu_stats)
+               return -ENOMEM;
+
+       /*
+        * successful_cnt will be set to 0 after session
+        * is established for the first time
+        */
+       stats->reconnects.successful_cnt = -1;
+
+       return 0;
+}