重写检查是否需要调度;新增系统调用返回前检查是否需要重新调度;新增waitq唤醒任务的时候标记需要重新调度

diff --git a/include/sched.h b/include/sched.h
index 47322ec71fec4123d2a561eae0ad20482ca2f769..edb494521588022717dad867890864596e2b1c1a 100644 (file)
--- a/include/sched.h
+++ b/include/sched.h
@@ -25,6 +25,10 @@
 
 void schedule();
 
+void set_need_schedule();
+void clear_need_schedule();
+bool need_schedule();
+
 extern task_t root_task;
 
 extern void load_cr3(task_t* tsk);

diff --git a/include/task.h b/include/task.h
index dcb263d3e39ef3ffd2543f0620bf8be17ece0940..5b1d60440aa6451290a107e87cd506256b8a049c 100644 (file)
--- a/include/task.h
+++ b/include/task.h
@@ -59,9 +59,6 @@ typedef union task_union {
         int ticks;
 
         int priority;
-        int64_t jiffies;
-
-        volatile int need_resched;
 
         pid_t pid;
         pid_t ppid;

diff --git a/kernel/clock.c b/kernel/clock.c
index ab1881e82c0a21b2b4bca36870592ac427efc16c..209deea1c47e22eb358a0253bea3eaebc24daf81 100644 (file)
--- a/kernel/clock.c
+++ b/kernel/clock.c
@@ -25,8 +25,6 @@ extern volatile bool enable_clock_irq_delay;
 void clk_handler(unsigned int irq, pt_regs_t* regs, void* dev_id) {
     jiffies++;
 
-    current->jiffies = jiffies;
-
 #if ENABLE_CLOCK_IRQ_WAIT
     if (enable_clock_irq_delay) {
         return;
@@ -36,6 +34,10 @@ void clk_handler(unsigned int irq, pt_regs_t* regs, void* dev_id) {
 
     current->ticks--;
 
+    if (current->ticks <= 0) {
+        set_need_schedule();
+    }
+
     if (reenter == 0) {
         add_irq_bh_handler(clk_bh_handler, NULL);
     }

diff --git a/kernel/fork.c b/kernel/fork.c
index 962a1b07c48d0e0bff20b0cf6e97ef25f213c896..5f8053668827a8af6ba8954c315e358048e3a195 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -85,7 +85,6 @@ int do_fork(pt_regs_t* regs, unsigned long flags) {
     tsk->priority = current->priority;
     tsk->ticks = tsk->priority;
 
-    tsk->need_resched = 0;
     tsk->sched_cnt = 0;
     tsk->sched_keep_cnt = 0;
 

diff --git a/kernel/irq.c b/kernel/irq.c
index 4264233259bdd074d61af11a3a504e35140cd4d2..5100c9d324f75a7d0ab352c2b1f60c37e5c64f68 100644 (file)
--- a/kernel/irq.c
+++ b/kernel/irq.c
@@ -21,6 +21,7 @@
 #include <system.h>
 #include <task.h>
 #include <clock.h>
+#include <sched.h>
 
 irq_desc_t irq_desc[NR_IRQS];
 irq_bh_action_t* irq_bh_actions = NULL;
@@ -91,13 +92,9 @@ __attribute__((regparm(1))) void irq_handler(pt_regs_t* regs) {
     reenter--;
 
     // 考察如果不需要调度程序，直接退出
-    // if (current->need_resched == 0) {
-    //     return;
-    // }
-
-    // if (irq != 0) {
-    //     return;
-    // }
+    if (!need_schedule()) {
+        return;
+    }
 
     enable_irq();
 

diff --git a/kernel/sched.c b/kernel/sched.c
index e4705d2302509f83a1319fdefd192bbd15dd9468..bdafccc6cf808993aafd6cb744cbd5865f8743d7 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -57,7 +57,6 @@ void init_root_task() {
     root_task.priority = 7;
     root_task.ticks = root_task.priority;
     root_task.vma_list = NULL;
-    root_task.need_resched = 0;
     root_task.sched_cnt = 0;
     root_task.sched_keep_cnt = 0;
     root_task.magic = TASK_MAGIC;
@@ -134,6 +133,7 @@ void schedule() {
     unsigned long eflags;
     irq_save(eflags);
 
+    // 把自己挂到就绪队列尾部
     if (prev->state == TASK_READY || prev->state == TASK_RUN) {
         task_set_ready(prev);
     }
@@ -156,6 +156,8 @@ end:
         prev->ticks = prev->priority;
     }
 
+    clear_need_schedule();
+
     if (prev != next) {
         next->sched_cnt++;
         context_switch(prev, next);
@@ -176,10 +178,10 @@ void add_task_for_monitor(task_t* tsk) {
 void task_set_run(task_t* t) {
     assert(t != NULL);
 
-    if (t == &root_task) {
-        t->state = TASK_RUN;
-        return;
-    }
+    // if (t == &root_task) {
+    //     t->state = TASK_RUN;
+    //     return;
+    // }
 
     assert(t->state == TASK_READY);
 
@@ -229,4 +231,20 @@ void task_init_lists(task_t* t) {
     INIT_LIST_HEAD(&t->list);
     INIT_LIST_HEAD(&t->ready_list);
     INIT_LIST_HEAD(&t->waitq_list);
+}
+
+///
+
+static volatile bool _need_schedule = false;
+
+void set_need_schedule() {
+    _need_schedule = true;
+}
+
+void clear_need_schedule() {
+    _need_schedule = false;
+}
+
+bool need_schedule() {
+    return _need_schedule;
 }
\ No newline at end of file

diff --git a/kernel/syscall.S b/kernel/syscall.S
index a1fce5546e30a19913017e9d5bb7e470dcfbc787..657e4e56ace4f25a3025a9fa81a331e427b9d560 100644 (file)
--- a/kernel/syscall.S
+++ b/kernel/syscall.S
@@ -27,6 +27,7 @@
 .global syscall_entry
 .global ret_from_fork_krnl
 .extern reenter
+.extern sysc_check_resched
 //.global syscall_exit
 
 syscall_entry:
@@ -72,6 +73,8 @@ syscall_entry:
     // 保存返回值
     movl    %eax, PT_REGS_EAX(%esp)
 
+    call sysc_check_resched
+
 
     RESTORE_REGS
 

diff --git a/kernel/syscall.c b/kernel/syscall.c
index 8f8dcbb47fb9ece324c92f18a11dddf01734dc02..0dfb2ce13934fc66b1171596e04926dd3169dabd 100644 (file)
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -129,3 +129,14 @@ int sysc_bad_nr() {
 
     return -1;
 }
+
+void sysc_check_resched() {
+    unsigned long eflags;
+    irq_save(eflags);
+    if (need_schedule()) {
+        if (!IN_CRITICAL_ZONE()) {
+            schedule();
+        }
+    }
+    irq_restore(eflags);
+}
\ No newline at end of file

diff --git a/kernel/waitq.c b/kernel/waitq.c
index ad8ea708d82318f830976aa8c9248c8531785e65..1502fe21f04dabbdbed446e3e0cceca61de273be 100644 (file)
--- a/kernel/waitq.c
+++ b/kernel/waitq.c
@@ -32,6 +32,9 @@ void waitq_wakeup(waitq_t* waitq, int cnt) {
     assert(waitq != NULL);
     assert(cnt >= 0);
 
+    // 是否唤醒了任务，如果唤醒了任务就将当前任务标记为需要调度，以便新任务更快可以被调度
+    bool woken_task = false;
+
     for (int i = 0; ((i < cnt) || (cnt == 0)); i++) {
         if (list_empty(&waitq->list)) {
             break;
@@ -44,6 +47,12 @@ void waitq_wakeup(waitq_t* waitq, int cnt) {
         list_del_init(&task->waitq_list);
 
         task_set_ready(task);
+
+        woken_task = true;
+    }
+
+    if (woken_task) {
+        set_need_schedule();
     }
 }