From: Chuck Lever <chuck.lever@oracle.com>
Date: Wed, 18 Dec 2019 15:18:15 -0500
Subject: RDMA/core: Trace points for diagnosing completion queue issues
Patch-mainline: v5.6-rc1
Git-commit: 3e5901cbfcc15da54f6ad148add754e7a2b2a558
References: jsc#SLE-8449
Sample trace events:
kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE
<idle>-0 [002] 120.056292: cq_schedule: cq.id=4
kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt
kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1
<idle>-0 [002] 120.067503: cq_schedule: cq.id=4
kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt
kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1
<idle>-0 [002] 120.067657: cq_schedule: cq.id=4
kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt
kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1
...
systemd-1 [002] 122.392653: cq_schedule: cq.id=4
kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt
kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16
kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16
kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16
kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16
kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3
Several features to note in this output:
- The WCE count and context type are reported at allocation time
- The CPU and kworker for each CQ is evident
- The CQ's restracker ID is tagged on each trace event
- CQ poll scheduling latency is measured
- Details about how often single completions occur versus multiple
completions are evident
- The cost of the ULP's completion handler is recorded
Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/core/Makefile | 3
drivers/infiniband/core/cq.c | 27 +++
drivers/infiniband/core/trace.c | 14 ++
drivers/infiniband/core/verbs.c | 4
include/rdma/ib_verbs.h | 5
include/trace/events/rdma_core.h | 271 +++++++++++++++++++++++++++++++++++++++
6 files changed, 320 insertions(+), 4 deletions(-)
create mode 100644 drivers/infiniband/core/trace.c
create mode 100644 include/trace/events/rdma_core.h
--- a/drivers/infiniband/core/Makefile
+++ b/drivers/infiniband/core/Makefile
@@ -11,7 +11,8 @@ ib_core-y := packer.o ud_header.o verb
device.o fmr_pool.o cache.o netlink.o \
roce_gid_mgmt.o mr_pool.o addr.o sa_query.o \
multicast.o mad.o smi.o agent.o mad_rmpp.o \
- nldev.o restrack.o counters.o ib_core_uverbs.o
+ nldev.o restrack.o counters.o ib_core_uverbs.o \
+ trace.o
ib_core-$(CONFIG_SECURITY_INFINIBAND) += security.o
ib_core-$(CONFIG_CGROUP_RDMA) += cgroup.o
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -7,6 +7,8 @@
#include <linux/slab.h>
#include <rdma/ib_verbs.h>
+#include <trace/events/rdma_core.h>
+
/* # of WCs to poll for with a single call to ib_poll_cq */
#define IB_POLL_BATCH 16
#define IB_POLL_BATCH_DIRECT 8
@@ -41,6 +43,7 @@ static void ib_cq_rdma_dim_work(struct w
dim->state = DIM_START_MEASURE;
+ trace_cq_modify(cq, comps, usec);
cq->device->ops.modify_cq(cq, comps, usec);
}
@@ -65,18 +68,29 @@ static void rdma_dim_init(struct ib_cq *
INIT_WORK(&dim->work, ib_cq_rdma_dim_work);
}
+static int __poll_cq(struct ib_cq *cq, int num_entries, struct ib_wc *wc)
+{
+ int rc;
+
+ rc = ib_poll_cq(cq, num_entries, wc);
+ trace_cq_poll(cq, num_entries, rc);
+ return rc;
+}
+
static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *wcs,
int batch)
{
int i, n, completed = 0;
+ trace_cq_process(cq);
+
/*
* budget might be (-1) if the caller does not
* want to bound this call, thus we need unsigned
* minimum here.
*/
- while ((n = ib_poll_cq(cq, min_t(u32, batch,
- budget - completed), wcs)) > 0) {
+ while ((n = __poll_cq(cq, min_t(u32, batch,
+ budget - completed), wcs)) > 0) {
for (i = 0; i < n; i++) {
struct ib_wc *wc = &wcs[i];
@@ -131,8 +145,10 @@ static int ib_poll_handler(struct irq_po
completed = __ib_process_cq(cq, budget, cq->wc, IB_POLL_BATCH);
if (completed < budget) {
irq_poll_complete(&cq->iop);
- if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
+ if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) {
+ trace_cq_reschedule(cq);
irq_poll_sched(&cq->iop);
+ }
}
if (dim)
@@ -143,6 +159,7 @@ static int ib_poll_handler(struct irq_po
static void ib_cq_completion_softirq(struct ib_cq *cq, void *private)
{
+ trace_cq_schedule(cq);
irq_poll_sched(&cq->iop);
}
@@ -162,6 +179,7 @@ static void ib_cq_poll_work(struct work_
static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private)
{
+ trace_cq_schedule(cq);
queue_work(cq->comp_wq, &cq->work);
}
@@ -239,6 +257,7 @@ struct ib_cq *__ib_alloc_cq_user(struct
goto out_destroy_cq;
}
+ trace_cq_alloc(cq, nr_cqe, comp_vector, poll_ctx);
return cq;
out_destroy_cq:
@@ -248,6 +267,7 @@ out_free_wc:
kfree(cq->wc);
out_free_cq:
kfree(cq);
+ trace_cq_alloc_error(nr_cqe, comp_vector, poll_ctx, ret);
return ERR_PTR(ret);
}
EXPORT_SYMBOL(__ib_alloc_cq_user);
@@ -304,6 +324,7 @@ void ib_free_cq_user(struct ib_cq *cq, s
WARN_ON_ONCE(1);
}
+ trace_cq_free(cq);
rdma_restrack_del(&cq->res);
cq->device->ops.destroy_cq(cq, udata);
if (cq->dim)
--- /dev/null
+++ b/drivers/infiniband/core/trace.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Trace points for core RDMA functions.
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#define CREATE_TRACE_POINTS
+
+#include <rdma/ib_verbs.h>
+
+#include <trace/events/rdma_core.h>
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -53,6 +53,8 @@
#include "core_priv.h"
+#include <trace/events/rdma_core.h>
+
static int ib_resolve_eth_dmac(struct ib_device *device,
struct rdma_ah_attr *ah_attr);
@@ -2785,6 +2787,7 @@ void ib_drain_sq(struct ib_qp *qp)
qp->device->ops.drain_sq(qp);
else
__ib_drain_sq(qp);
+ trace_cq_drain_complete(qp->send_cq);
}
EXPORT_SYMBOL(ib_drain_sq);
@@ -2813,6 +2816,7 @@ void ib_drain_rq(struct ib_qp *qp)
qp->device->ops.drain_rq(qp);
else
__ib_drain_rq(qp);
+ trace_cq_drain_complete(qp->recv_cq);
}
EXPORT_SYMBOL(ib_drain_rq);
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1558,6 +1558,11 @@ struct ib_cq {
};
struct workqueue_struct *comp_wq;
struct dim *dim;
+
+ /* updated only by trace points */
+ ktime_t timestamp;
+ bool interrupt;
+
/*
* Implementation details of the RDMA core, don't use in drivers:
*/
--- /dev/null
+++ b/include/trace/events/rdma_core.h
@@ -0,0 +1,271 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Trace point definitions for core RDMA functions.
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rdma_core
+
+#if !defined(_TRACE_RDMA_CORE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RDMA_CORE_H
+
+#include <linux/tracepoint.h>
+#include <rdma/ib_verbs.h>
+
+/*
+ * enum ib_poll_context, from include/rdma/ib_verbs.h
+ */
+#define IB_POLL_CTX_LIST \
+ ib_poll_ctx(DIRECT) \
+ ib_poll_ctx(SOFTIRQ) \
+ ib_poll_ctx(WORKQUEUE) \
+ ib_poll_ctx_end(UNBOUND_WORKQUEUE)
+
+#undef ib_poll_ctx
+#undef ib_poll_ctx_end
+
+#define ib_poll_ctx(x) TRACE_DEFINE_ENUM(IB_POLL_##x);
+#define ib_poll_ctx_end(x) TRACE_DEFINE_ENUM(IB_POLL_##x);
+
+IB_POLL_CTX_LIST
+
+#undef ib_poll_ctx
+#undef ib_poll_ctx_end
+
+#define ib_poll_ctx(x) { IB_POLL_##x, #x },
+#define ib_poll_ctx_end(x) { IB_POLL_##x, #x }
+
+#define rdma_show_ib_poll_ctx(x) \
+ __print_symbolic(x, IB_POLL_CTX_LIST)
+
+/**
+ ** Completion Queue events
+ **/
+
+TRACE_EVENT(cq_schedule,
+ TP_PROTO(
+ struct ib_cq *cq
+ ),
+
+ TP_ARGS(cq),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ ),
+
+ TP_fast_assign(
+ cq->timestamp = ktime_get();
+ cq->interrupt = true;
+
+ __entry->cq_id = cq->res.id;
+ ),
+
+ TP_printk("cq.id=%u", __entry->cq_id)
+);
+
+TRACE_EVENT(cq_reschedule,
+ TP_PROTO(
+ struct ib_cq *cq
+ ),
+
+ TP_ARGS(cq),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ ),
+
+ TP_fast_assign(
+ cq->timestamp = ktime_get();
+ cq->interrupt = false;
+
+ __entry->cq_id = cq->res.id;
+ ),
+
+ TP_printk("cq.id=%u", __entry->cq_id)
+);
+
+TRACE_EVENT(cq_process,
+ TP_PROTO(
+ const struct ib_cq *cq
+ ),
+
+ TP_ARGS(cq),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ __field(bool, interrupt)
+ __field(s64, latency)
+ ),
+
+ TP_fast_assign(
+ ktime_t latency = ktime_sub(ktime_get(), cq->timestamp);
+
+ __entry->cq_id = cq->res.id;
+ __entry->latency = ktime_to_us(latency);
+ __entry->interrupt = cq->interrupt;
+ ),
+
+ TP_printk("cq.id=%u wake-up took %lld [us] from %s",
+ __entry->cq_id, __entry->latency,
+ __entry->interrupt ? "interrupt" : "reschedule"
+ )
+);
+
+TRACE_EVENT(cq_poll,
+ TP_PROTO(
+ const struct ib_cq *cq,
+ int requested,
+ int rc
+ ),
+
+ TP_ARGS(cq, requested, rc),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ __field(int, requested)
+ __field(int, rc)
+ ),
+
+ TP_fast_assign(
+ __entry->cq_id = cq->res.id;
+ __entry->requested = requested;
+ __entry->rc = rc;
+ ),
+
+ TP_printk("cq.id=%u requested %d, returned %d",
+ __entry->cq_id, __entry->requested, __entry->rc
+ )
+);
+
+TRACE_EVENT(cq_drain_complete,
+ TP_PROTO(
+ const struct ib_cq *cq
+ ),
+
+ TP_ARGS(cq),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ ),
+
+ TP_fast_assign(
+ __entry->cq_id = cq->res.id;
+ ),
+
+ TP_printk("cq.id=%u",
+ __entry->cq_id
+ )
+);
+
+
+TRACE_EVENT(cq_modify,
+ TP_PROTO(
+ const struct ib_cq *cq,
+ u16 comps,
+ u16 usec
+ ),
+
+ TP_ARGS(cq, comps, usec),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ __field(unsigned int, comps)
+ __field(unsigned int, usec)
+ ),
+
+ TP_fast_assign(
+ __entry->cq_id = cq->res.id;
+ __entry->comps = comps;
+ __entry->usec = usec;
+ ),
+
+ TP_printk("cq.id=%u comps=%u usec=%u",
+ __entry->cq_id, __entry->comps, __entry->usec
+ )
+);
+
+TRACE_EVENT(cq_alloc,
+ TP_PROTO(
+ const struct ib_cq *cq,
+ int nr_cqe,
+ int comp_vector,
+ enum ib_poll_context poll_ctx
+ ),
+
+ TP_ARGS(cq, nr_cqe, comp_vector, poll_ctx),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ __field(int, nr_cqe)
+ __field(int, comp_vector)
+ __field(unsigned long, poll_ctx)
+ ),
+
+ TP_fast_assign(
+ __entry->cq_id = cq->res.id;
+ __entry->nr_cqe = nr_cqe;
+ __entry->comp_vector = comp_vector;
+ __entry->poll_ctx = poll_ctx;
+ ),
+
+ TP_printk("cq.id=%u nr_cqe=%d comp_vector=%d poll_ctx=%s",
+ __entry->cq_id, __entry->nr_cqe, __entry->comp_vector,
+ rdma_show_ib_poll_ctx(__entry->poll_ctx)
+ )
+);
+
+TRACE_EVENT(cq_alloc_error,
+ TP_PROTO(
+ int nr_cqe,
+ int comp_vector,
+ enum ib_poll_context poll_ctx,
+ int rc
+ ),
+
+ TP_ARGS(nr_cqe, comp_vector, poll_ctx, rc),
+
+ TP_STRUCT__entry(
+ __field(int, rc)
+ __field(int, nr_cqe)
+ __field(int, comp_vector)
+ __field(unsigned long, poll_ctx)
+ ),
+
+ TP_fast_assign(
+ __entry->rc = rc;
+ __entry->nr_cqe = nr_cqe;
+ __entry->comp_vector = comp_vector;
+ __entry->poll_ctx = poll_ctx;
+ ),
+
+ TP_printk("nr_cqe=%d comp_vector=%d poll_ctx=%s rc=%d",
+ __entry->nr_cqe, __entry->comp_vector,
+ rdma_show_ib_poll_ctx(__entry->poll_ctx), __entry->rc
+ )
+);
+
+TRACE_EVENT(cq_free,
+ TP_PROTO(
+ const struct ib_cq *cq
+ ),
+
+ TP_ARGS(cq),
+
+ TP_STRUCT__entry(
+ __field(u32, cq_id)
+ ),
+
+ TP_fast_assign(
+ __entry->cq_id = cq->res.id;
+ ),
+
+ TP_printk("cq.id=%u", __entry->cq_id)
+);
+
+#endif /* _TRACE_RDMA_CORE_H */
+
+#include <trace/define_trace.h>