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From 7a3bd078facd9167ea69d3edcc3bbd67735b872e Mon Sep 17 00:00:00 2001
From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Sat, 30 Sep 2017 17:27:08 -0400
Subject: [PATCH 2115/4131] drm/amdkfd: Use wait_queue_t to implement event
waiting
Change-Id: I8d61da196352637a55c1e0e14d9981d3447cde06
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_events.c | 53 +++++++++++----------------------
drivers/gpu/drm/amd/amdkfd/kfd_events.h | 3 +-
2 files changed, 19 insertions(+), 37 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
index a4cf3f4..0baf130 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
@@ -36,22 +36,12 @@
#include <linux/device.h>
/*
- * A task can only be on a single wait_queue at a time, but we need to support
- * waiting on multiple events (any/all).
- * Instead of each event simply having a wait_queue with sleeping tasks, it
- * has a singly-linked list of tasks.
- * A thread that wants to sleep creates an array of these, one for each event
- * and adds one to each event's waiter chain.
+ * Wrapper around wait_queue_t (wait queue entry)
*/
struct kfd_event_waiter {
- struct list_head waiters;
- struct task_struct *sleeping_task;
-
- /* Transitions to true when the event this belongs to is signaled. */
- bool activated;
-
- /* Event */
- struct kfd_event *event;
+ wait_queue_t wait;
+ struct kfd_event *event; /* Event to wait for */
+ bool activated; /* Becomes true when event is signaled */
};
#define SLOTS_PER_PAGE KFD_SIGNAL_EVENT_LIMIT
@@ -398,17 +388,12 @@ void kfd_event_init_process(struct kfd_process *p)
static void destroy_event(struct kfd_process *p, struct kfd_event *ev)
{
- /* Wake up pending waiters. They will return failure */
- while (!list_empty(&ev->waiters)) {
- struct kfd_event_waiter *waiter =
- list_first_entry(&ev->waiters, struct kfd_event_waiter,
- waiters);
+ struct kfd_event_waiter *waiter;
+ /* Wake up pending waiters. They will return failure */
+ list_for_each_entry(waiter, &ev->wq.task_list, wait.task_list)
waiter->event = NULL;
- /* _init because free_waiters will call list_del */
- list_del_init(&waiter->waiters);
- wake_up_process(waiter->sleeping_task);
- }
+ wake_up_all(&ev->wq);
if (ev->signal_page) {
release_event_notification_slot(ev->signal_page,
@@ -486,7 +471,7 @@ int kfd_event_create(struct file *devkfd, struct kfd_process *p,
ev->auto_reset = auto_reset;
ev->signaled = false;
- INIT_LIST_HEAD(&ev->waiters);
+ init_waitqueue_head(&ev->wq);
mutex_lock(&p->event_mutex);
@@ -547,19 +532,14 @@ int kfd_event_destroy(struct kfd_process *p, uint32_t event_id)
static void set_event(struct kfd_event *ev)
{
struct kfd_event_waiter *waiter;
- struct kfd_event_waiter *next;
/* Auto reset if the list is non-empty and we're waking someone. */
- ev->signaled = !ev->auto_reset || list_empty(&ev->waiters);
+ ev->signaled = !ev->auto_reset || !waitqueue_active(&ev->wq);
- list_for_each_entry_safe(waiter, next, &ev->waiters, waiters) {
+ list_for_each_entry(waiter, &ev->wq.task_list, wait.task_list)
waiter->activated = true;
- /* _init because free_waiters will call list_del */
- list_del_init(&waiter->waiters);
-
- wake_up_process(waiter->sleeping_task);
- }
+ wake_up_all(&ev->wq);
}
/* Assumes that p is current. */
@@ -679,8 +659,7 @@ static struct kfd_event_waiter *alloc_event_waiters(uint32_t num_events)
GFP_KERNEL);
for (i = 0; (event_waiters) && (i < num_events) ; i++) {
- INIT_LIST_HEAD(&event_waiters[i].waiters);
- event_waiters[i].sleeping_task = current;
+ init_wait(&event_waiters[i].wait);
event_waiters[i].activated = false;
}
@@ -711,7 +690,7 @@ static void init_event_waiter_add_to_waitlist(struct kfd_event_waiter *waiter)
* wait on this event.
*/
if (!waiter->activated)
- list_add(&waiter->waiters, &ev->waiters);
+ add_wait_queue(&ev->wq, &waiter->wait);
}
/* test_event_condition - Test condition of events being waited for
@@ -801,7 +780,9 @@ static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters)
uint32_t i;
for (i = 0; i < num_events; i++)
- list_del(&waiters[i].waiters);
+ if (waiters[i].event)
+ remove_wait_queue(&waiters[i].event->wq,
+ &waiters[i].wait);
kfree(waiters);
}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.h b/drivers/gpu/drm/amd/amdkfd/kfd_events.h
index 28f6838..96f9122 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.h
@@ -27,6 +27,7 @@
#include <linux/hashtable.h>
#include <linux/types.h>
#include <linux/list.h>
+#include <linux/wait.h>
#include "kfd_priv.h"
#include <uapi/linux/kfd_ioctl.h>
@@ -56,7 +57,7 @@ struct kfd_event {
int type;
- struct list_head waiters; /* List of kfd_event_waiter by waiters. */
+ wait_queue_head_t wq; /* List of event waiters. */
/* Only for signal events. */
struct signal_page *signal_page;
--
2.7.4
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