鸿蒙内核源码分析(CPU篇) | 内核是如何描述CPU的 ?

    百万汉字注解 + 百篇博客分析 -> 鸿蒙内核源码

README.md

@@ -9,7 +9,7 @@
 
 ## **百万汉字注解**
 
-**[kernel\_liteos\_a_note](https://gitee.com/weharmony/kernel_liteos_a_note)** 是在鸿蒙官方开源项目 **[kernel\_liteos\_a](https://gitee.com/openharmony/kernel_liteos_a)** 基础上给源码加上中文注解的版本,目前几大核心模块加注已基本完成, **整体加注完成70%**, 正持续加注完善中 ...
+**[kernel\_liteos\_a_note](https://gitee.com/weharmony/kernel_liteos_a_note)** 是在鸿蒙官方开源项目 **[kernel\_liteos\_a](https://gitee.com/openharmony/kernel_liteos_a)** 基础上给源码加上中文注解的版本,目前几大核心模块加注已基本完成, **整体加注完成70%**
 
 ### **为何要精读内核源码?**
 
@@ -67,6 +67,8 @@
 
 ### **进程/线程**
 
+* (CPU篇) | 内核是如何描述CPU的 ?[<  CSDN](https://blog.csdn.net/kuangyufei/article/details/113782749) [ | OSCHINA  >](https://my.oschina.net/weharmony/blog/4952034)
+
 * (并发并行篇) | 内核如何管理多个CPU？[<  CSDN](https://blog.csdn.net/kuangyufei/article/details/113516222) [ | OSCHINA  >](https://my.oschina.net/u/3751245/blog/4940329)
 
 * (调度机制篇) | 任务是如何被调度执行的？[<  CSDN](https://blog.csdn.net/kuangyufei/article/details/108705968) [ | OSCHINA  >](https://my.oschina.net/u/3751245/blog/4623040)
@@ -158,11 +160,11 @@
 
 ### **参与贡献**
 
-* 1. Fork 本仓库 >> 新建 Feat_xxx 分支 >> 提交代码注解 >> [新建 Pull Request](https://gitee.com/weharmony/kernel_liteos_a_note/pull/new/weharmony:master...weharmony:master)
+* Fork 本仓库 >> 新建 Feat_xxx 分支 >> 提交代码注解 >> [新建 Pull Request](https://gitee.com/weharmony/kernel_liteos_a_note/pull/new/weharmony:master...weharmony:master)
 
-* 2. [新建 Issue](https://gitee.com/weharmony/kernel_liteos_a_note/issues)
+* [新建 Issue](https://gitee.com/weharmony/kernel_liteos_a_note/issues)
 
-### **喜欢就请收藏吧**
+### **喜欢就大方 点赞+关注+收藏 吧**
 
 各大站点搜 **"鸿蒙内核源码分析"**  ,快速找到组织.
 

kernel/base/core/los_task.c

@@ -231,7 +231,7 @@ LITE_OS_SEC_TEXT_MINOR VOID OsTaskPriModify(LosTaskCB *taskCB, UINT16 priority)
         taskCB->priority = priority;
     }
 }
-//把任务加到定时器链表中
+//把任务加到CPU等待链表中
 LITE_OS_SEC_TEXT STATIC INLINE VOID OsAdd2TimerList(LosTaskCB *taskCB, UINT32 timeOut)
 {
     SET_SORTLIST_VALUE(&taskCB->sortList, timeOut);//设置idxRollNum的值为timeOut

kernel/base/include/los_percpu_pri.h

@@ -50,15 +50,13 @@ typedef enum {
 } ExcFlag;
 #endif
 
-typedef struct {
-    SortLinkAttribute taskSortLink;             /* task sort link */	//每个CPU core 都有一个task排序链表
-    SortLinkAttribute swtmrSortLink;            /* swtmr sort link */	//每个CPU core 都有一个定时器排序链表
-
+typedef struct {//内核对cpu的描述
+    SortLinkAttribute taskSortLink;             /* task sort link */	//task wait/delay 排序链表
+    SortLinkAttribute swtmrSortLink;            /* swtmr sort link */	//定时器排序链表
     UINT32 idleTaskID;                          /* idle task id */		//空闲任务ID 见于 OsIdleTaskCreate
     UINT32 taskLockCnt;                         /* task lock flag */	//任务锁的数量,当 > 0 的时候,需要重新调度了
     UINT32 swtmrHandlerQueue;                   /* software timer timeout queue id */	//软时钟超时队列句柄
     UINT32 swtmrTaskID;                         /* software timer task id */	//软时钟任务ID
-
     UINT32 schedFlag;                           /* pending scheduler flag */	//调度标识 INT_NO_RESCH INT_PEND_RESCH
 #if (LOSCFG_KERNEL_SMP == YES)
     UINT32 excFlag;                             /* cpu halt or exc flag */	//CPU处于停止或运行的标识

kernel/base/include/los_sched_pri.h

-/*
- * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
- * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this list of
- *    conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice, this list
- *    of conditions and the following disclaimer in the documentation and/or other materials
- *    provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its contributors may be used
- *    to endorse or promote products derived from this software without specific prior written
- *    permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef _LOS_SCHED_PRI_H
-#define _LOS_SCHED_PRI_H
-
-#include "los_percpu_pri.h"
-#include "los_hwi.h"
-
-#ifdef __cplusplus
-#if __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-#endif /* __cplusplus */
-
-extern UINT32 g_taskScheduled;
-//调度标志,一个位代表一个CPU核,这么看鸿蒙最大支持32核,例如:4个CPU,每个4核 就一共16个核,足够了.该标志用于在调用OSStartToRun之前防止内核调度
-/*
- * Schedule flag, one bit represents one core.
- * This flag is used to prevent kernel scheduling before OSStartToRun.
- */
-#define OS_SCHEDULER_SET(cpuid) do {     \
-    g_taskScheduled |= (1U << (cpuid));  \
-} while (0);//对应位设置为1
-
-#define OS_SCHEDULER_CLR(cpuid) do {     \
-    g_taskScheduled &= ~(1U << (cpuid)); \
-} while (0);//对应位设置为0
-
-#define OS_SCHEDULER_ACTIVE (g_taskScheduled & (1U << ArchCurrCpuid()))//代表位上是否为1
-
-typedef enum {
-    INT_NO_RESCH = 0,   /* no needs to schedule */
-    INT_PEND_RESCH,     /* pending schedule flag */
-} SchedFlag;
-
-/* Check if preemptable with counter flag */
-STATIC INLINE BOOL OsPreemptable(VOID)//是否可抢占
-{
-    /*
-     * Unlike OsPreemptableInSched, the int may be not disabled when OsPreemptable
-     * is called, needs mannually disable interrupt, to prevent current task from
-     * being migrated to another core, and get the wrong preeptable status.
-     */
-     //与OsPreemptableInSched不同，当OsPreemptable时，中断可能不会被禁用,所以调用时，需要手动禁用中断，以防止当前任务
-	 //被迁移到另一个CPU核上，并得到错误的可接受状态。
-    UINT32 intSave = LOS_IntLock();//手动禁用中断
-    BOOL preemptable = (OsPercpuGet()->taskLockCnt == 0);
-    if (!preemptable) {
-        /* Set schedule flag if preemption is disabled */
-        OsPercpuGet()->schedFlag = INT_PEND_RESCH;//如果禁用抢占，则设置调度标志
-    }
-    LOS_IntRestore(intSave);//手动恢复中断
-    return preemptable;
-}
-
-STATIC INLINE BOOL OsPreemptableInSched(VOID)
-{
-    BOOL preemptable = FALSE;
-
-#if (LOSCFG_KERNEL_SMP == YES)
-    /*
-     * For smp systems, schedule must hold the task spinlock, and this counter
-     * will increase by 1 in that case.
-     */
-    preemptable = (OsPercpuGet()->taskLockCnt == 1);//SMP时 taskLockCnt=1 才能执行调度任务
-
-#else
-    preemptable = (OsPercpuGet()->taskLockCnt == 0);
-#endif
-    if (!preemptable) {
-        /* Set schedule flag if preemption is disabled */
-        OsPercpuGet()->schedFlag = INT_PEND_RESCH;//重新调度
-    }
-
-    return preemptable;
-}
-
-/*
- * This function simply picks the next task and switches to it.
- * Current task needs to already be in the right state or the right
- * queues it needs to be in.
- */
-extern VOID OsSchedResched(VOID);
-
-/*
- * This function put the current task back to the ready queue and
- * try to do the schedule. However, the schedule won't be definitely
- * taken place while there're no other higher priority tasks or locked.
- */
-extern VOID OsSchedPreempt(VOID);
-
-/*
- * Just like OsSchedPreempt, except this function will do the OS_INT_ACTIVE
- * check, in case the schedule taken place in the middle of an interrupt.
- */
-STATIC INLINE VOID LOS_Schedule(VOID)
-{
-    if (OS_INT_ACTIVE) {//硬件中断是否激活,注意调度是需要切换任务上下文的
-        OsPercpuGet()->schedFlag = INT_PEND_RESCH;//
-        return;
-    }
-
-    /*
-     * trigger schedule in task will also do the slice check
-     * if neccessary, it will give up the timeslice more in time.
-     * otherwhise, there's no other side effects.
-     */
-    OsSchedPreempt();//抢占式调度
-}
-
-#ifdef __cplusplus
-#if __cplusplus
-}
-#endif /* __cplusplus */
-#endif /* __cplusplus */
-
-#endif /* _LOS_SCHED_PRI_H */
+/*
+ * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
+ * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ *    conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *    of conditions and the following disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used
+ *    to endorse or promote products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _LOS_SCHED_PRI_H
+#define _LOS_SCHED_PRI_H
+
+#include "los_percpu_pri.h"
+#include "los_hwi.h"
+
+#ifdef __cplusplus
+#if __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+#endif /* __cplusplus */
+
+extern UINT32 g_taskScheduled;
+//调度标志,一个位代表一个CPU核,这么看鸿蒙最大支持32核,例如:4个CPU,每个4核 就一共16个核,足够了.该标志用于在调用OSStartToRun之前防止内核调度
+/*
+ * Schedule flag, one bit represents one core.
+ * This flag is used to prevent kernel scheduling before OSStartToRun.
+ */
+#define OS_SCHEDULER_SET(cpuid) do {     \
+    g_taskScheduled |= (1U << (cpuid));  \
+} while (0);//对应位设置为1
+
+#define OS_SCHEDULER_CLR(cpuid) do {     \
+    g_taskScheduled &= ~(1U << (cpuid)); \
+} while (0);//对应位设置为0
+
+#define OS_SCHEDULER_ACTIVE (g_taskScheduled & (1U << ArchCurrCpuid()))//代表位上是否为1
+
+typedef enum {
+    INT_NO_RESCH = 0,   /* no needs to schedule */
+    INT_PEND_RESCH,     /* pending schedule flag */
+} SchedFlag;
+
+/* Check if preemptable with counter flag */
+STATIC INLINE BOOL OsPreemptable(VOID)//是否可抢占
+{
+    /*
+     * Unlike OsPreemptableInSched, the int may be not disabled when OsPreemptable
+     * is called, needs mannually disable interrupt, to prevent current task from
+     * being migrated to another core, and get the wrong preeptable status.
+     */
+     //与OsPreemptableInSched不同，当OsPreemptable时，中断可能不会被禁用,所以调用时，需要手动禁用中断，以防止当前任务
+	 //被迁移到另一个CPU核上，并得到错误的可接受状态。
+    UINT32 intSave = LOS_IntLock();//手动禁用中断
+    BOOL preemptable = (OsPercpuGet()->taskLockCnt == 0);
+    if (!preemptable) {
+        /* Set schedule flag if preemption is disabled */
+        OsPercpuGet()->schedFlag = INT_PEND_RESCH;//如果禁用抢占，则设置调度标志
+    }
+    LOS_IntRestore(intSave);//手动恢复中断
+    return preemptable;
+}
+
+STATIC INLINE BOOL OsPreemptableInSched(VOID)
+{
+    BOOL preemptable = FALSE;
+
+#if (LOSCFG_KERNEL_SMP == YES)
+    /*
+     * For smp systems, schedule must hold the task spinlock, and this counter
+     * will increase by 1 in that case.
+     */
+    preemptable = (OsPercpuGet()->taskLockCnt == 1);//SMP时 taskLockCnt=1 才能执行调度任务
+
+#else
+    preemptable = (OsPercpuGet()->taskLockCnt == 0);
+#endif
+    if (!preemptable) {
+        /* Set schedule flag if preemption is disabled */
+        OsPercpuGet()->schedFlag = INT_PEND_RESCH;//重新调度
+    }
+
+    return preemptable;
+}
+
+/*
+ * This function simply picks the next task and switches to it.
+ * Current task needs to already be in the right state or the right
+ * queues it needs to be in.
+ */
+extern VOID OsSchedResched(VOID);
+
+/*
+ * This function put the current task back to the ready queue and
+ * try to do the schedule. However, the schedule won't be definitely
+ * taken place while there're no other higher priority tasks or locked.
+ */
+extern VOID OsSchedPreempt(VOID);
+
+/*
+ * Just like OsSchedPreempt, except this function will do the OS_INT_ACTIVE
+ * check, in case the schedule taken place in the middle of an interrupt.
+ */
+STATIC INLINE VOID LOS_Schedule(VOID)
+{
+    if (OS_INT_ACTIVE) {//发生硬件中断,调度被阻塞
+        OsPercpuGet()->schedFlag = INT_PEND_RESCH;//
+        return;
+    }
+
+    /*
+     * trigger schedule in task will also do the slice check
+     * if neccessary, it will give up the timeslice more in time.
+     * otherwhise, there's no other side effects.
+     */
+    OsSchedPreempt();//抢占式调度
+}
+
+#ifdef __cplusplus
+#if __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* __cplusplus */
+
+#endif /* _LOS_SCHED_PRI_H */

kernel/base/include/los_task_pri.h

@@ -311,7 +311,7 @@ typedef struct {
     CHAR            taskName[OS_TCB_NAME_LEN]; /**< Task name */	//任务的名称
     LOS_DL_LIST     pendList;           /**< Task pend node */		//如果任务阻塞时就通过它挂到各种阻塞情况的链表上,比如OsTaskWait时
     LOS_DL_LIST     threadList;         /**< thread list */			//挂到所属进程的线程链表上
-    SortLinkList    sortList;           /**< Task sortlink node */	//挂到cpu core 的任务执行链表上
+    SortLinkList    sortList;           /**< Task sortlink node */	//task wait,delay时挂到cpu core的taskSortLink链表上
     UINT32          eventMask;          /**< Event mask */			//对哪些事件进行屏蔽
     UINT32          eventMode;          /**< Event mode */			//事件三种模式(LOS_WAITMODE_AND,LOS_WAITMODE_OR,LOS_WAITMODE_CLR)
     UINT32          priBitMap;          /**< BitMap for recording the change of task priority,	//任务在执行过程中优先级会经常变化，这个变量用来记录所有曾经变化

zzz/git/push.sh

 git add -A
-git commit -m  '鸿蒙内核源码分析(定时器机制篇) | 内核最高优先级任务是谁???
+git commit -m  '鸿蒙内核源码分析(CPU篇) | 内核是如何描述CPU的 ?
     百万汉字注解 + 百篇博客分析 -> 鸿蒙内核源码
 '