mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-10-29 11:06:29 +08:00
Aaron Tomlin
8bbd858c47
Bottom-Half (BH) workqueues execute work items in softirq context. To prevent softirqs from starving user and kernel threads, bh_worker() enforces execution limits (i.e., BH_WORKER_JIFFIES and BH_WORKER_RESTARTS). When keep_working() is still true but either the time slice or restart count is exhausted, bh_worker() yields execution and re-raises the softirq via kick_bh_pool(). Currently, there is no observability into when a BH worker hits these limits and is forced to yield. Add the workqueue_bh_budget_yield tracepoint, emitted when bh_worker() exits the processing loop with pending work items remaining. It records, the worker pool ID, pool CPU, number of loop restarts consumed, a boolean flag indicating whether the yield was due to a time slice timeout, and a boolean flag indicating whether this is a high-priority BH pool. Signed-off-by: Aaron Tomlin <atomlin@atomlin.com> Signed-off-by: Tejun Heo <tj@kernel.org>
279 lines
6.9 KiB
C
279 lines
6.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#undef TRACE_SYSTEM
|
|
#define TRACE_SYSTEM workqueue
|
|
|
|
#if !defined(_TRACE_WORKQUEUE_H) || defined(TRACE_HEADER_MULTI_READ)
|
|
#define _TRACE_WORKQUEUE_H
|
|
|
|
#include <linux/tracepoint.h>
|
|
#include <linux/workqueue.h>
|
|
|
|
struct pool_workqueue;
|
|
struct worker_pool;
|
|
|
|
/**
|
|
* workqueue_queue_work - called when a work gets queued
|
|
* @req_cpu: the requested cpu
|
|
* @pwq: pointer to struct pool_workqueue
|
|
* @work: pointer to struct work_struct
|
|
*
|
|
* This event occurs when a work is queued immediately or once a
|
|
* delayed work is actually queued on a workqueue (ie: once the delay
|
|
* has been reached).
|
|
*/
|
|
TRACE_EVENT(workqueue_queue_work,
|
|
|
|
TP_PROTO(int req_cpu, struct pool_workqueue *pwq,
|
|
struct work_struct *work),
|
|
|
|
TP_ARGS(req_cpu, pwq, work),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( void *, work )
|
|
__field( void *, function)
|
|
__string( workqueue, pwq->wq->name)
|
|
__field( int, req_cpu )
|
|
__field( int, cpu )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->work = work;
|
|
__entry->function = work->func;
|
|
__assign_str(workqueue);
|
|
__entry->req_cpu = req_cpu;
|
|
__entry->cpu = pwq->pool->cpu;
|
|
),
|
|
|
|
TP_printk("work struct=%p function=%ps workqueue=%s req_cpu=%d cpu=%d",
|
|
__entry->work, __entry->function, __get_str(workqueue),
|
|
__entry->req_cpu, __entry->cpu)
|
|
);
|
|
|
|
/**
|
|
* workqueue_activate_work - called when a work gets activated
|
|
* @work: pointer to struct work_struct
|
|
*
|
|
* This event occurs when a queued work is put on the active queue,
|
|
* which happens immediately after queueing unless @max_active limit
|
|
* is reached.
|
|
*/
|
|
TRACE_EVENT(workqueue_activate_work,
|
|
|
|
TP_PROTO(struct work_struct *work),
|
|
|
|
TP_ARGS(work),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( void *, work )
|
|
__field( void *, function)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->work = work;
|
|
__entry->function = work->func;
|
|
),
|
|
|
|
TP_printk("work struct %p function=%ps ", __entry->work, __entry->function)
|
|
);
|
|
|
|
/**
|
|
* workqueue_execute_start - called immediately before the workqueue callback
|
|
* @work: pointer to struct work_struct
|
|
*
|
|
* Allows to track workqueue execution.
|
|
*/
|
|
TRACE_EVENT(workqueue_execute_start,
|
|
|
|
TP_PROTO(struct work_struct *work),
|
|
|
|
TP_ARGS(work),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( void *, work )
|
|
__field( void *, function)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->work = work;
|
|
__entry->function = work->func;
|
|
),
|
|
|
|
TP_printk("work struct %p: function %ps", __entry->work, __entry->function)
|
|
);
|
|
|
|
/**
|
|
* workqueue_execute_end - called immediately after the workqueue callback
|
|
* @work: pointer to struct work_struct
|
|
* @function: pointer to worker function
|
|
*
|
|
* Allows to track workqueue execution.
|
|
*/
|
|
TRACE_EVENT(workqueue_execute_end,
|
|
|
|
TP_PROTO(struct work_struct *work, work_func_t function),
|
|
|
|
TP_ARGS(work, function),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( void *, work )
|
|
__field( void *, function)
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->work = work;
|
|
__entry->function = function;
|
|
),
|
|
|
|
TP_printk("work struct %p: function %ps", __entry->work, __entry->function)
|
|
);
|
|
|
|
/**
|
|
* workqueue_cpu_intensive - called when a work item exceeds cpu_intensive threshold
|
|
* @pwq: pointer to struct pool_workqueue
|
|
* @work: pointer to struct work_struct
|
|
* @function: pointer to worker function
|
|
* @duration_us: CPU time consumed in microseconds
|
|
*
|
|
* This event occurs when a concurrency-managed work item runs for longer
|
|
* than wq_cpu_intensive_thresh_us without sleeping and is excluded from
|
|
* concurrency management to prevent stalling other work items.
|
|
*/
|
|
TRACE_EVENT(workqueue_cpu_intensive,
|
|
|
|
TP_PROTO(struct pool_workqueue *pwq, struct work_struct *work,
|
|
work_func_t function, u64 duration_us),
|
|
|
|
TP_ARGS(pwq, work, function, duration_us),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( void *, work )
|
|
__field( void *, function )
|
|
__string( workqueue, pwq->wq->name )
|
|
__field( int, cpu )
|
|
__field( u64, duration_us )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->work = work;
|
|
__entry->function = function;
|
|
__assign_str(workqueue);
|
|
__entry->cpu = pwq->pool->cpu;
|
|
__entry->duration_us = duration_us;
|
|
),
|
|
|
|
TP_printk("work struct=%p function=%ps workqueue=%s cpu=%d duration_us=%llu",
|
|
__entry->work, __entry->function, __get_str(workqueue),
|
|
__entry->cpu, __entry->duration_us)
|
|
);
|
|
|
|
/**
|
|
* workqueue_mayday - called when a pool_workqueue sends mayday to rescuer
|
|
* @pwq: pointer to struct pool_workqueue
|
|
*
|
|
* This event occurs when a worker pool fails to create a new worker and
|
|
* requests the workqueue's rescuer thread to process pending works.
|
|
*/
|
|
TRACE_EVENT(workqueue_mayday,
|
|
|
|
TP_PROTO(struct pool_workqueue *pwq),
|
|
|
|
TP_ARGS(pwq),
|
|
|
|
TP_STRUCT__entry(
|
|
__string( workqueue, pwq->wq->name )
|
|
__field( int, pool_id )
|
|
__field( int, cpu )
|
|
__field( int, nr_active )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__assign_str(workqueue);
|
|
__entry->pool_id = pwq->pool->id;
|
|
__entry->cpu = pwq->pool->cpu;
|
|
__entry->nr_active = pwq->nr_active;
|
|
),
|
|
|
|
TP_printk("workqueue=%s pool_id=%d cpu=%d nr_active=%d",
|
|
__get_str(workqueue), __entry->pool_id, __entry->cpu,
|
|
__entry->nr_active)
|
|
);
|
|
|
|
/**
|
|
* workqueue_rescued - called when a work item is assigned to a rescuer
|
|
* @pwq: pointer to struct pool_workqueue
|
|
* @work: pointer to struct work_struct
|
|
* @function: pointer to worker function
|
|
*
|
|
* This event occurs when a work item is claimed by a rescuer thread
|
|
* to guarantee forward progress.
|
|
*/
|
|
TRACE_EVENT(workqueue_rescued,
|
|
|
|
TP_PROTO(struct pool_workqueue *pwq, struct work_struct *work,
|
|
work_func_t function),
|
|
|
|
TP_ARGS(pwq, work, function),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( void *, work )
|
|
__field( void *, function )
|
|
__string( workqueue, pwq->wq->name )
|
|
__field( int, cpu )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->work = work;
|
|
__entry->function = function;
|
|
__assign_str(workqueue);
|
|
__entry->cpu = pwq->pool->cpu;
|
|
),
|
|
|
|
TP_printk("work struct=%p function=%ps workqueue=%s cpu=%d",
|
|
__entry->work, __entry->function, __get_str(workqueue),
|
|
__entry->cpu)
|
|
);
|
|
|
|
/**
|
|
* workqueue_bh_budget_yield - called when a BH worker yields due to budget exhaustion
|
|
* @pool: pointer to struct worker_pool
|
|
* @restarts: number of restarts executed
|
|
* @timeout: whether execution hit the time limit (BH_WORKER_JIFFIES)
|
|
* @highpri: whether this is a high-priority BH pool
|
|
*
|
|
* This event occurs when a bottom-half (BH) worker pool running in softirq
|
|
* context exhausts its execution time slice or restart limit and must yield
|
|
* execution.
|
|
*/
|
|
TRACE_EVENT(workqueue_bh_budget_yield,
|
|
|
|
TP_PROTO(struct worker_pool *pool, int restarts, bool timeout, bool highpri),
|
|
|
|
TP_ARGS(pool, restarts, timeout, highpri),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( int, pool_id )
|
|
__field( int, cpu )
|
|
__field( int, restarts )
|
|
__field( bool, timeout )
|
|
__field( bool, highpri )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->pool_id = pool->id;
|
|
__entry->cpu = pool->cpu;
|
|
__entry->restarts = restarts;
|
|
__entry->timeout = timeout;
|
|
__entry->highpri = highpri;
|
|
),
|
|
|
|
TP_printk("pool_id=%d cpu=%d restarts=%d timeout=%d highpri=%d",
|
|
__entry->pool_id, __entry->cpu, __entry->restarts,
|
|
__entry->timeout, __entry->highpri)
|
|
);
|
|
|
|
#endif /* _TRACE_WORKQUEUE_H */
|
|
|
|
/* This part must be outside protection */
|
|
#include <trace/define_trace.h>
|
|
|