nuttx/sched/sched/queue.h
hujun5 ed998c08c4 sched: change the SMP scheduling policy from synchronous to asynchronous
reason:
Currently, if we need to schedule a task to another CPU, we have to completely halt the other CPU,
manipulate the scheduling linked list, and then resume the operation of that CPU. This process is both time-consuming and unnecessary.

During this process, both the current CPU and the target CPU are inevitably subjected to busyloop.

The improved strategy is to simply send a cross-core interrupt to the target CPU.
The current CPU continues to run while the target CPU responds to the interrupt, eliminating the certainty of a busyloop occurring.

Signed-off-by: hujun5 <hujun5@xiaomi.com>
2024-10-09 23:32:31 +08:00

77 lines
2.4 KiB
C

/****************************************************************************
* sched/sched/queue.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_SCHED_SCHED_NUTTX_QUEUE_H
#define __INCLUDE_SCHED_SCHED_NUTTX_QUEUE_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/queue.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define dq_addfirst_nonempty(p, q) \
do \
{ \
FAR dq_entry_t *tmp_node = (p); \
tmp_node->blink = NULL; \
tmp_node->flink = (q)->head; \
(q)->head->blink = tmp_node; \
(q)->head = tmp_node; \
} \
while (0)
#define dq_rem_head(p, q) \
do \
{ \
FAR dq_entry_t *tmp_node = (p); \
FAR dq_entry_t *tmp_next = tmp_node->flink; \
(q)->head = tmp_next; \
tmp_next->blink = NULL; \
tmp_node->flink = NULL; \
} \
while (0)
#define dq_rem_mid(p) \
do \
{ \
FAR dq_entry_t *tmp_prev = (FAR dq_entry_t *)p->blink; \
FAR dq_entry_t *tmp_next = (FAR dq_entry_t *)p->flink; \
tmp_prev->flink = tmp_next; \
tmp_next->blink = tmp_prev; \
} \
while (0)
#define dq_insert_mid(pre, mid, next) \
do \
{ \
mid->flink = next; \
mid->blink = prev; \
pre->flink = mid; \
next->blink = mid; \
} \
while (0)
#endif /* __INCLUDE_NUTTX_QUEUE_H_ */