Re: [PATCH v9 07/25] RDMA/rtrs: client: statistics functions

[Jinpu Wang <jinpu.wang@cloud.ionos.com>]

On Tue, Mar 3, 2020 at 12:29 PM Leon Romanovsky <leon@kernel.org> wrote:
>
> On Fri, Feb 21, 2020 at 11:47:03AM +0100, Jack Wang wrote:
> > From: Jack Wang <jinpu.wang@cloud.ionos.com>
> >
> > 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.
> >
> > Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> > Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> > ---
> >  drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c | 205 +++++++++++++++++++
> >  1 file changed, 205 insertions(+)
> >  create mode 100644 drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
> >
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
> > new file mode 100644
> > index 000000000000..3f556b884a4e
> > --- /dev/null
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-stats.c
> > @@ -0,0 +1,205 @@
> > +// 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);
>
> How will user know that first value is successful_cnt and second 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);
>
> Same question.
>
> Thanks
Hi Leon,

For all the sysfs entries, we documented in Documentation, in your
cases, it's in Documentation/ABI/testing/sysfs-class-rtrs-client,
in Patch 14.

Thanks!