From: "tip-bot2 for Steven Rostedt (VMware)" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
x86 <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: [tip: sched/core] sched: Have sched_class_highest define by vmlinux.lds.h
Date: Thu, 25 Jun 2020 11:53:25 -0000 [thread overview]
Message-ID: <159308600506.16989.4684187013846395025.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20191219214558.682913590@goodmis.org>
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) <rostedt@goodmis.org>
AuthorDate: Thu, 19 Dec 2019 16:44:53 -05:00
Committer: Peter Zijlstra <peterz@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) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191219214558.682913590@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;
next prev parent reply other threads:[~2020-06-25 11:54 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 21:44 [RFC][PATCH 0/4] sched: Optimizations to sched_class processing Steven Rostedt
2019-12-19 21:44 ` [RFC][PATCH 1/4] sched: Force the address order of each sched class descriptor Steven Rostedt
2019-12-20 8:52 ` Rasmus Villemoes
2019-12-20 10:00 ` Peter Zijlstra
2019-12-20 10:12 ` Rasmus Villemoes
2019-12-20 10:44 ` Kirill Tkhai
2019-12-20 15:18 ` Steven Rostedt
2019-12-20 12:19 ` Peter Zijlstra
2019-12-20 14:34 ` Rasmus Villemoes
2019-12-19 21:44 ` [RFC][PATCH 2/4] sched: Have sched_class_highest define by vmlinux.lds.h Steven Rostedt
2019-12-20 8:52 ` Rasmus Villemoes
2020-06-25 11:53 ` tip-bot2 for Steven Rostedt (VMware) [this message]
2019-12-19 21:44 ` [RFC][PATCH 3/4] sched: Remove struct sched_class next field Steven Rostedt
2019-12-20 12:14 ` Rasmus Villemoes
2020-06-25 11:53 ` [tip: sched/core] sched: Remove struct sched_class::next field tip-bot2 for Steven Rostedt (VMware)
2019-12-19 21:44 ` [RFC][PATCH 4/4] sched: Micro optimization in pick_next_task() and in check_preempt_curr() Steven Rostedt
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