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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2019-12-19 16:44:53 -0500
committerPeter Zijlstra <peterz@infradead.org>2020-06-25 13:45:44 +0200
commitc3a340f7e7eadac7662ab104ceb16432e5a4c6b2 (patch)
tree806761b75cc761bc4ef6b48a5228fb384c90598d /kernel/sched
parent590d69796346353878b275c5512c664e3f875f24 (diff)
downloadlinux-c3a340f7e7eadac7662ab104ceb16432e5a4c6b2.tar.bz2
sched: Have sched_class_highest define by vmlinux.lds.h
Now that the sched_class descriptors are defined by the linker script, and this needs to be aware of the existance of stop_sched_class when SMP is enabled or not, as it is used as the "highest" priority when defined. Move the declaration of sched_class_highest to the same location in the linker script that inserts stop_sched_class, and this will also make it easier to see what should be defined as the highest class, as this linker script location defines the priorities as well. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191219214558.682913590@goodmis.org
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/core.c8
-rw-r--r--kernel/sched/sched.h17
2 files changed, 17 insertions, 8 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0208b71bef80..81640fe0eae8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6646,6 +6646,14 @@ void __init sched_init(void)
unsigned long ptr = 0;
int i;
+ /* Make sure the linker didn't screw up */
+ BUG_ON(&idle_sched_class + 1 != &fair_sched_class ||
+ &fair_sched_class + 1 != &rt_sched_class ||
+ &rt_sched_class + 1 != &dl_sched_class);
+#ifdef CONFIG_SMP
+ BUG_ON(&dl_sched_class + 1 != &stop_sched_class);
+#endif
+
wait_bit_init();
#ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 336887607b3d..4165c06d1d7b 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1811,7 +1811,7 @@ struct sched_class {
#ifdef CONFIG_FAIR_GROUP_SCHED
void (*task_change_group)(struct task_struct *p, int type);
#endif
-};
+} __aligned(32); /* STRUCT_ALIGN(), vmlinux.lds.h */
static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
{
@@ -1825,17 +1825,18 @@ static inline void set_next_task(struct rq *rq, struct task_struct *next)
next->sched_class->set_next_task(rq, next, false);
}
-#ifdef CONFIG_SMP
-#define sched_class_highest (&stop_sched_class)
-#else
-#define sched_class_highest (&dl_sched_class)
-#endif
+/* Defined in include/asm-generic/vmlinux.lds.h */
+extern struct sched_class __begin_sched_classes[];
+extern struct sched_class __end_sched_classes[];
+
+#define sched_class_highest (__end_sched_classes - 1)
+#define sched_class_lowest (__begin_sched_classes - 1)
#define for_class_range(class, _from, _to) \
- for (class = (_from); class != (_to); class = class->next)
+ for (class = (_from); class != (_to); class--)
#define for_each_class(class) \
- for_class_range(class, sched_class_highest, NULL)
+ for_class_range(class, sched_class_highest, sched_class_lowest)
extern const struct sched_class stop_sched_class;
extern const struct sched_class dl_sched_class;