On Fri, 2019-05-31 at 09:25 -0400, Chuck Lever wrote:
> > On May 30, 2019, at 6:33 PM, Bruce Fields <bfields@xxxxxxxxxxxx>
> > wrote:
> >
> > On Thu, May 30, 2019 at 06:19:54PM -0400, Chuck Lever wrote:
> > >
> > >
> > > > On May 30, 2019, at 5:38 PM, bfields@xxxxxxxxxxxx wrote:
> > > >
> > > > On Thu, May 23, 2019 at 04:13:50PM -0400, Dave Wysochanski
> > > > wrote:
> > > > > We often see various error conditions with NFS4.x that show
> > > > > up with
> > > > > a very high operation count all completing with tk_status < 0
> > > > > in a
> > > > > short period of time. Add a count to rpc_iostats to record
> > > > > on a
> > > > > per-op basis the ops that complete in this manner, which will
> > > > > enable lower overhead diagnostics.
> > > >
> > > > Looks like a good idea to me.
> > > >
> > > > It's too bad we can't distinguish the errors. (E.g. ESTALE on
> > > > a lookup
> > > > call is a lot more interesting than ENOENT.) But understood
> > > > that
> > > > maintaining (number of possible errors) * (number of possible
> > > > ops)
> > > > counters is probably overkill, so just counting the number of
> > > > errors
> > > > seems like a good start.
> > >
> > > We now have trace points that can do that too.
> >
> > You mean, that can report every error (and its value)?
>
> Yes, the nfs_xdr_status trace point reports the error by value and
> symbolic name.
>
The tracepoint is very useful I agree. I don't think it will show:
a) the mount
b) the opcode
Or am I mistaken and there's a way to get those with a filter or
another tracepoint?
>
> > I assume having these statistics in mountstats is still useful,
> > though.
> >
> > --b.
> >
> > >
> > >
> > > > --b.
> > > >
> > > > >
> > > > > Signed-off-by: Dave Wysochanski <dwysocha@xxxxxxxxxx>
> > > > > ---
> > > > > include/linux/sunrpc/metrics.h | 7 ++++++-
> > > > > net/sunrpc/stats.c | 8 ++++++--
> > > > > 2 files changed, 12 insertions(+), 3 deletions(-)
> > > > >
> > > > > diff --git a/include/linux/sunrpc/metrics.h
> > > > > b/include/linux/sunrpc/metrics.h
> > > > > index 1b3751327575..0ee3f7052846 100644
> > > > > --- a/include/linux/sunrpc/metrics.h
> > > > > +++ b/include/linux/sunrpc/metrics.h
> > > > > @@ -30,7 +30,7 @@
> > > > > #include <linux/ktime.h>
> > > > > #include <linux/spinlock.h>
> > > > >
> > > > > -#define RPC_IOSTATS_VERS "1.0"
> > > > > +#define RPC_IOSTATS_VERS "1.1"
> > > > >
> > > > > struct rpc_iostats {
> > > > > spinlock_t om_lock;
> > > > > @@ -66,6 +66,11 @@ struct rpc_iostats {
> > > > > ktime_t om_queue, /* queued for
> > > > > xmit */
> > > > > om_rtt, /* RPC RTT */
> > > > > om_execute; /* RPC
> > > > > execution */
> > > > > + /*
> > > > > + * The count of operations that complete with tk_status
> > > > > < 0.
> > > > > + * These statuses usually indicate error conditions.
> > > > > + */
> > > > > + unsigned long om_error_status;
> > > > > } ____cacheline_aligned;
> > > > >
> > > > > struct rpc_task;
> > > > > diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c
> > > > > index 8b2d3c58ffae..737414247ca7 100644
> > > > > --- a/net/sunrpc/stats.c
> > > > > +++ b/net/sunrpc/stats.c
> > > > > @@ -176,6 +176,8 @@ void rpc_count_iostats_metrics(const
> > > > > struct rpc_task *task,
> > > > >
> > > > > execute = ktime_sub(now, task->tk_start);
> > > > > op_metrics->om_execute = ktime_add(op_metrics-
> > > > > >om_execute, execute);
> > > > > + if (task->tk_status < 0)
> > > > > + op_metrics->om_error_status++;
> > > > >
> > > > > spin_unlock(&op_metrics->om_lock);
> > > > >
> > > > > @@ -218,13 +220,14 @@ static void _add_rpc_iostats(struct
> > > > > rpc_iostats *a, struct rpc_iostats *b)
> > > > > a->om_queue = ktime_add(a->om_queue, b->om_queue);
> > > > > a->om_rtt = ktime_add(a->om_rtt, b->om_rtt);
> > > > > a->om_execute = ktime_add(a->om_execute, b-
> > > > > >om_execute);
> > > > > + a->om_error_status += b->om_error_status;
> > > > > }
> > > > >
> > > > > static void _print_rpc_iostats(struct seq_file *seq, struct
> > > > > rpc_iostats *stats,
> > > > > int op, const struct
> > > > > rpc_procinfo *procs)
> > > > > {
> > > > > _print_name(seq, op, procs);
> > > > > - seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu
> > > > > %llu\n",
> > > > > + seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %llu
> > > > > %lu\n",
> > > > > stats->om_ops,
> > > > > stats->om_ntrans,
> > > > > stats->om_timeouts,
> > > > > @@ -232,7 +235,8 @@ static void _print_rpc_iostats(struct
> > > > > seq_file *seq, struct rpc_iostats *stats,
> > > > > stats->om_bytes_recv,
> > > > > ktime_to_ms(stats->om_queue),
> > > > > ktime_to_ms(stats->om_rtt),
> > > > > - ktime_to_ms(stats->om_execute));
> > > > > + ktime_to_ms(stats->om_execute),
> > > > > + stats->om_error_status);
> > > > > }
> > > > >
> > > > > void rpc_clnt_show_stats(struct seq_file *seq, struct
> > > > > rpc_clnt *clnt)
> > > > > --
> > > > > 2.20.1
> > >
> > > --
> > > Chuck Lever
>
> --
> Chuck Lever
>
>
>
