From: Peter Zijlstra <peterz@infradead.org>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@suse.de>,
Michal Hocko <mhocko@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E . McKenney" <paulmck@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Michal Hocko <mhocko@suse.com>
Subject: Re: [RFC PATCH 6/8] preempt/dynamic: Provide preempt_schedule[_notrace]() static calls
Date: Thu, 21 Jan 2021 22:58:26 +0100 [thread overview]
Message-ID: <20210121215826.GB16371@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20210118141223.123667-7-frederic@kernel.org>
On Mon, Jan 18, 2021 at 03:12:21PM +0100, Frederic Weisbecker wrote:
> diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
> index 69485ca13665..3db9cb8b1a25 100644
> --- a/arch/x86/include/asm/preempt.h
> +++ b/arch/x86/include/asm/preempt.h
> @@ -5,6 +5,7 @@
> #include <asm/rmwcc.h>
> #include <asm/percpu.h>
> #include <linux/thread_info.h>
> +#include <linux/static_call_types.h>
>
> DECLARE_PER_CPU(int, __preempt_count);
>
> @@ -103,16 +104,33 @@ static __always_inline bool should_resched(int preempt_offset)
> }
>
> #ifdef CONFIG_PREEMPTION
> - extern asmlinkage void preempt_schedule_thunk(void);
> -# define __preempt_schedule() \
> - asm volatile ("call preempt_schedule_thunk" : ASM_CALL_CONSTRAINT)
>
> - extern asmlinkage void preempt_schedule(void);
> - extern asmlinkage void preempt_schedule_notrace_thunk(void);
> -# define __preempt_schedule_notrace() \
> - asm volatile ("call preempt_schedule_notrace_thunk" : ASM_CALL_CONSTRAINT)
> +extern asmlinkage void preempt_schedule(void);
> +extern asmlinkage void preempt_schedule_thunk(void);
> +
> +#define __preempt_schedule_func() preempt_schedule_thunk
> +
> +DECLARE_STATIC_CALL(preempt_schedule, __preempt_schedule_func());
> +
> +#define __preempt_schedule() \
> +do { \
> + __ADDRESSABLE(STATIC_CALL_KEY(preempt_schedule)); \
> + asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule) : ASM_CALL_CONSTRAINT); \
> +} while (0)
> +
> +extern asmlinkage void preempt_schedule_notrace(void);
> +extern asmlinkage void preempt_schedule_notrace_thunk(void);
> +
> +#define __preempt_schedule_notrace_func() preempt_schedule_notrace_thunk
> +
> +DECLARE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func());
> +
> +#define __preempt_schedule_notrace() \
> +do { \
> + __ADDRESSABLE(STATIC_CALL_KEY(preempt_schedule_notrace)); \
> + asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule_notrace) : ASM_CALL_CONSTRAINT); \
> +} while (0)
>
> - extern asmlinkage void preempt_schedule_notrace(void);
> #endif
I'm thinking the above doesn't build for !PREEMPT_DYNAMIC, given it
relies on the STATIC_CALL unconditionally, but we only define it for
PREEMPT_DYNAMIC:
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index d6de12b4eef2..faff4b546c5f 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -5251,6 +5251,12 @@ asmlinkage __visible void __sched notrace preempt_schedule(void)
> NOKPROBE_SYMBOL(preempt_schedule);
> EXPORT_SYMBOL(preempt_schedule);
>
> +#ifdef CONFIG_PREEMPT_DYNAMIC
> +DEFINE_STATIC_CALL(preempt_schedule, __preempt_schedule_func());
> +EXPORT_STATIC_CALL(preempt_schedule);
> +#endif
> +
> +
> /**
> * preempt_schedule_notrace - preempt_schedule called by tracing
> *
> @@ -5303,6 +5309,12 @@ asmlinkage __visible void __sched notrace preempt_schedule_notrace(void)
> }
> EXPORT_SYMBOL_GPL(preempt_schedule_notrace);
>
> +#ifdef CONFIG_PREEMPT_DYNAMIC
> +DEFINE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func());
> +EXPORT_STATIC_CALL(preempt_schedule_notrace);
> +#endif
> +
> +
> #endif /* CONFIG_PREEMPTION */
>
> /*
> --
> 2.25.1
>
next prev parent reply other threads:[~2021-01-21 22:03 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-18 14:12 [RFC PATCH 0/7] preempt: Tune preemption flavour on boot v4 Frederic Weisbecker
2021-01-18 14:12 ` [RFC PATCH 1/8] static_call/x86: Add __static_call_return0() Frederic Weisbecker
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra
2021-01-18 14:12 ` [RFC PATCH 2/8] static_call: Provide DEFINE_STATIC_CALL_RET0() Frederic Weisbecker
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2021-02-17 13:17 ` tip-bot2 for Frederic Weisbecker
2021-01-18 14:12 ` [RFC PATCH 3/8] static_call: Pull some static_call declarations to the type headers Frederic Weisbecker
2021-01-19 10:46 ` Jürgen Groß
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra
2021-01-18 14:12 ` [RFC PATCH 4/8] preempt: Introduce CONFIG_PREEMPT_DYNAMIC Frederic Weisbecker
2021-01-22 16:53 ` Peter Zijlstra
2021-01-28 12:17 ` Frederic Weisbecker
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Michal Hocko
2021-02-17 13:17 ` tip-bot2 for Michal Hocko
2021-01-18 14:12 ` [RFC PATCH 5/8] preempt/dynamic: Provide cond_resched() and might_resched() static calls Frederic Weisbecker
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra (Intel)
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra (Intel)
2021-01-18 14:12 ` [RFC PATCH 6/8] preempt/dynamic: Provide preempt_schedule[_notrace]() " Frederic Weisbecker
2021-01-21 21:58 ` Peter Zijlstra [this message]
2021-01-21 22:25 ` Peter Zijlstra
2021-01-22 16:52 ` Peter Zijlstra
2021-01-22 16:57 ` Ard Biesheuvel
2021-01-22 17:08 ` Peter Zijlstra
2021-02-08 12:00 ` [tip: sched/core] sched: Add /debug/sched_preempt tip-bot2 for Peter Zijlstra
2021-02-09 15:45 ` tip-bot2 for Peter Zijlstra
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra
2021-01-25 23:40 ` [RFC PATCH 6/8] preempt/dynamic: Provide preempt_schedule[_notrace]() static calls Josh Poimboeuf
2021-01-26 9:24 ` Peter Zijlstra
2021-01-26 23:57 ` Josh Poimboeuf
2021-01-27 9:13 ` Peter Zijlstra
2021-01-27 11:27 ` Peter Zijlstra
2021-01-27 15:59 ` Josh Poimboeuf
2021-01-27 16:19 ` Peter Zijlstra
2021-01-27 16:33 ` Josh Poimboeuf
2021-01-27 18:44 ` Peter Zijlstra
2021-01-27 19:00 ` Josh Poimboeuf
2021-01-27 19:02 ` Josh Poimboeuf
2021-01-27 23:18 ` Josh Poimboeuf
2021-02-03 14:04 ` Peter Zijlstra
2021-02-05 15:30 ` Peter Zijlstra
2021-02-06 2:31 ` Josh Poimboeuf
2021-02-06 9:03 ` Peter Zijlstra
2021-02-05 15:22 ` Peter Zijlstra
2021-02-08 12:00 ` [tip: sched/core] static_call: Allow module use without exposing static_call_key tip-bot2 for Josh Poimboeuf
2021-02-09 15:45 ` tip-bot2 for Josh Poimboeuf
2021-02-17 13:17 ` tip-bot2 for Josh Poimboeuf
2021-02-08 12:00 ` [tip: sched/core] preempt/dynamic: Provide preempt_schedule[_notrace]() static calls tip-bot2 for Peter Zijlstra (Intel)
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra (Intel)
2021-01-18 14:12 ` [RFC PATCH 7/8] preempt/dynamic: Provide irqentry_exit_cond_resched() static call Frederic Weisbecker
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra (Intel)
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra (Intel)
2021-01-18 14:12 ` [RFC PATCH 8/8] preempt/dynamic: Support dynamic preempt with preempt= boot option Frederic Weisbecker
2021-02-08 12:00 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra (Intel)
2021-02-09 15:45 ` tip-bot2 for Peter Zijlstra (Intel)
2021-02-17 13:17 ` tip-bot2 for Peter Zijlstra (Intel)
2021-01-21 21:22 ` [RFC PATCH 0/7] preempt: Tune preemption flavour on boot v4 Peter Zijlstra
2021-01-22 15:02 ` Paul E. McKenney
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