Changeset bea6233 in mainline for kernel/generic/src/proc/scheduler.c

Timestamp:

2023-02-26T15:27:13Z (2 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

7cf5ddb

Parents:

deed510

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-02-26 15:18:02)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-02-26 15:27:13)

Message:

Replace cpu_sleep() with cpu_interruptible_sleep()

The new function combines interrupt reenabling with sleep,
so that a platform can implement this sequence atomically.
This is currently done only on ia32 and amd64.

File:

• kernel/generic/src/proc/scheduler.c (modified) (2 diffs)

kernel/generic/src/proc/scheduler.c

@@ -187 +187 @@
 
 loop:
-
         if (atomic_load(&CPU->nrdy) == 0) {
                 /*
@@ -197 +196 @@
                 CPU->idle = true;
                 irq_spinlock_unlock(&CPU->lock, false);
-                interrupts_enable();
 
                 /*
-                 * An interrupt might occur right now and wake up a thread.
-                 * In such case, the CPU will continue to go to sleep
-                 * even though there is a runnable thread.
+                 * Go to sleep with interrupts enabled.
+                 * Ideally, this should be atomic, but this is not guaranteed on
+                 * all platforms yet, so it is possible we will go sleep when
+                 * a thread has just become available.
                  */
-                cpu_sleep();
-                interrupts_disable();
+                cpu_interruptible_sleep();
+
+                /* Interrupts are disabled again. */
                 goto loop;
         }