> -----Original Message-----
> From: linux-rdma-owner@xxxxxxxxxxxxxxx <linux-rdma-
> owner@xxxxxxxxxxxxxxx> On Behalf Of Chuck Lever
> Sent: Saturday, October 12, 2019 2:43 PM
> To: linux-rdma@xxxxxxxxxxxxxxx
> Subject: [PATCH v4] IB/core: Trace points for diagnosing completion queue
> issues
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> drivers/infiniband/core/Makefile | 2
> drivers/infiniband/core/cq.c | 27 ++++
> drivers/infiniband/core/trace.c | 14 ++
> include/rdma/ib_verbs.h | 5 +
> include/trace/events/rdma_core.h | 251
> ++++++++++++++++++++++++++++++++++++++
> 5 files changed, 295 insertions(+), 4 deletions(-) create mode 100644
> drivers/infiniband/core/trace.c create mode 100644
> include/trace/events/rdma_core.h
>
> Changes since v3:
> - Reverted unnecessary behavior change in __ib_process_cq
> - Clarified what "id" is in trace point output
> - Added comment before new fields in struct ib_cq
> - New trace point that fires when there is a CQ allocation failure
>
> Changes since v2:
> - Removed extraneous changes to include/trace/events/rdma.h
>
> Changes since RFC:
> - Display CQ's global resource ID instead of it's pointer address
>
> diff --git a/drivers/infiniband/core/Makefile
> b/drivers/infiniband/core/Makefile
> index 09881bd..68d9e27 100644
> --- a/drivers/infiniband/core/Makefile
> +++ b/drivers/infiniband/core/Makefile
> @@ -11,7 +11,7 @@ ib_core-y := packer.o ud_header.o
> verbs.o cq.o rw.o sysfs.o \
> 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
> + nldev.o restrack.o counters.o trace.o
>
> ib_core-$(CONFIG_SECURITY_INFINIBAND) += security.o
> ib_core-$(CONFIG_CGROUP_RDMA) += cgroup.o diff --git
> a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c index
> bbfded6..e035895 100644
> --- 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 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 *cq)
> INIT_WORK(&dim->work, ib_cq_rdma_dim_work); }
>
> +static int __ib_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 = __ib_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_poll *iop, int
> budget)
> 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_poll *iop, int
> budget)
>
> 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_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 ib_device
> *dev, void *private,
> goto out_destroy_cq;
> }
>
> + trace_cq_alloc(cq, nr_cqe, comp_vector, poll_ctx);
> return cq;
>
> out_destroy_cq:
> @@ -248,6 +267,7 @@ struct ib_cq *__ib_alloc_cq_user(struct ib_device
> *dev, void *private,
> 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, struct
> ib_udata *udata)
> WARN_ON_ONCE(1);
> }
>
> + trace_cq_free(cq);
> rdma_restrack_del(&cq->res);
> cq->device->ops.destroy_cq(cq, udata);
> if (cq->dim)
> diff --git a/drivers/infiniband/core/trace.c b/drivers/infiniband/core/trace.c
> new file mode 100644 index 0000000..6c3514b
> --- /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@xxxxxxxxxx>
> + *
> + * 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>
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index
> 6a47ba8..43468a3 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -1555,6 +1555,11 @@ 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:
> */
> diff --git a/include/trace/events/rdma_core.h
> b/include/trace/events/rdma_core.h
> new file mode 100644
> index 0000000..0d56065
> --- /dev/null
> +++ b/include/trace/events/rdma_core.h
> @@ -0,0 +1,251 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Trace point definitions for core RDMA functions.
> + *
> + * Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
> + *
> + * 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>
> +#include <rdma/restrack.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, id)
> + ),
> +
> + TP_fast_assign(
> + cq->timestamp = ktime_get();
> + cq->interrupt = true;
> +
> + __entry->id = cq->res.id;
> + ),
> +
> + TP_printk("cq.id=%u", __entry->id)
> +);
> +
> +TRACE_EVENT(cq_reschedule,
> + TP_PROTO(
> + struct ib_cq *cq
> + ),
> +
> + TP_ARGS(cq),
> +
> + TP_STRUCT__entry(
> + __field(u32, id)
> + ),
> +
> + TP_fast_assign(
> + cq->timestamp = ktime_get();
> + cq->interrupt = false;
> +
> + __entry->id = cq->res.id;
> + ),
> +
> + TP_printk("cq.id=%u", __entry->id)
> +);
> +
> +TRACE_EVENT(cq_process,
> + TP_PROTO(
> + const struct ib_cq *cq
> + ),
> +
> + TP_ARGS(cq),
> +
> + TP_STRUCT__entry(
> + __field(s64, latency)
> + __field(u32, id)
> + __field(bool, interrupt)
> + ),
> +
> + TP_fast_assign(
> + ktime_t latency = ktime_sub(ktime_get(), cq->timestamp);
> +
> + __entry->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->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, id)
> + __field(int, requested)
> + __field(int, rc)
> + ),
> +
> + TP_fast_assign(
> + __entry->id = cq->res.id;
> + __entry->requested = requested;
> + __entry->rc = rc;
> + ),
> +
> + TP_printk("cq.id=%u requested %d, returned %d",
> + __entry->id, __entry->requested, __entry->rc
> + )
> +);
> +
> +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, id)
> + __field(unsigned int, comps)
> + __field(unsigned int, usec)
> + ),
> +
> + TP_fast_assign(
> + __entry->id = cq->res.id;
> + __entry->comps = comps;
> + __entry->usec = usec;
> + ),
> +
> + TP_printk("cq.id=%u comps=%u usec=%u",
> + __entry->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, id)
> + __field(int, nr_cqe)
> + __field(int, comp_vector)
> + __field(unsigned long, poll_ctx)
> + ),
> +
> + TP_fast_assign(
> + __entry->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->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, id)
> + ),
> +
> + TP_fast_assign(
> + __entry->id = cq->res.id;
> + ),
> +
> + TP_printk("cq.id=%u", __entry->id)
> +);
> +
> +#endif /* _TRACE_RDMA_CORE_H */
> +
> +#include <trace/define_trace.h>
Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
