The following commit has been merged into the sched/core branch of tip: Commit-ID: c3a340f7e7eadac7662ab104ceb16432e5a4c6b2 Gitweb: https://git.kernel.org/tip/c3a340f7e7eadac7662ab104ceb16432e5a4c6b2 Author: Steven Rostedt (VMware) <rost...@goodmis.org> AuthorDate: Thu, 19 Dec 2019 16:44:53 -05:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Thu, 25 Jun 2020 13:45:44 +02:00
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) <rost...@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Link: https://lkml.kernel.org/r/20191219214558.682913...@goodmis.org --- include/asm-generic/vmlinux.lds.h | 5 ++++- kernel/sched/core.c | 8 ++++++++ kernel/sched/sched.h | 17 +++++++++-------- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 2186d7b..66fb84c 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -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 diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0208b71..81640fe 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 3368876..4165c06 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;
