Commit c3a340f7 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware) Committed by Peter Zijlstra
Browse files

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: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191219214558.682913590@goodmis.org
parent 590d6979

include/asm-generic/vmlinux.lds.h

+4 −1
Original line number Diff line number Diff line
@@ -114,11 +114,14 @@ 
 * relation to each other.

 */

#define SCHED_DATA				\

	STRUCT_ALIGN();				\

	__begin_sched_classes = .;		\

	*(__idle_sched_class)			\

	*(__fair_sched_class)			\

	*(__rt_sched_class)			\

	*(__dl_sched_class)			\

	*(__stop_sched_class)

	*(__stop_sched_class)			\

	__end_sched_classes = .;



/*

 * Align to a 32 byte boundary equal to the

kernel/sched/core.c

+8 −0
Original line number Diff line number Diff line
@@ -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

kernel/sched/sched.h

+9 −8
Original line number Diff line number Diff line
@@ -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;

CRA Git | Maintained and supported by SUSTech CRA and CCSE