From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68BEEC433FE for ; Mon, 14 Feb 2022 16:52:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356688AbiBNQwo (ORCPT ); Mon, 14 Feb 2022 11:52:44 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:33028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347315AbiBNQwj (ORCPT ); Mon, 14 Feb 2022 11:52:39 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EF6106514F for ; Mon, 14 Feb 2022 08:52:30 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BD52B13D5; Mon, 14 Feb 2022 08:52:30 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C270E3F70D; Mon, 14 Feb 2022 08:52:28 -0800 (PST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: ardb@kernel.org, bp@alien8.de, catalin.marinas@arm.com, dave.hansen@linux.intel.com, frederic@kernel.org, james.morse@arm.com, joey.gouly@arm.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, luto@kernel.org, mark.rutland@arm.com, mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, valentin.schneider@arm.com, will@kernel.org Subject: [PATCH v4 2/7] sched/preempt: refactor sched_dynamic_update() Date: Mon, 14 Feb 2022 16:52:11 +0000 Message-Id: <20220214165216.2231574-3-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220214165216.2231574-1-mark.rutland@arm.com> References: <20220214165216.2231574-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently sched_dynamic_update needs to open-code the enabled/disabled function names for each preemption model it supports, when in practice this is a boolean enabled/disabled state for each function. Make this clearer and avoid repetition by defining the enabled/disabled states at the function definition, and using helper macros to perform the static_call_update(). Where x86 currently overrides the enabled function, it is made to provide both the enabled and disabled states for consistency, with defaults provided by the core code otherwise. In subsequent patches this will allow us to support PREEMPT_DYNAMIC without static calls. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Acked-by: Ard Biesheuvel Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Juri Lelli Cc: Peter Zijlstra Cc: Valentin Schneider --- arch/x86/include/asm/preempt.h | 10 +++--- include/linux/entry-common.h | 2 ++ kernel/sched/core.c | 59 +++++++++++++++++++++------------- 3 files changed, 45 insertions(+), 26 deletions(-) diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index fe5efbcba824..5f6daea1ee24 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -108,16 +108,18 @@ static __always_inline bool should_resched(int preempt_offset) extern asmlinkage void preempt_schedule(void); extern asmlinkage void preempt_schedule_thunk(void); -#define __preempt_schedule_func preempt_schedule_thunk +#define preempt_schedule_dynamic_enabled preempt_schedule_thunk +#define preempt_schedule_dynamic_disabled NULL extern asmlinkage void preempt_schedule_notrace(void); extern asmlinkage void preempt_schedule_notrace_thunk(void); -#define __preempt_schedule_notrace_func preempt_schedule_notrace_thunk +#define preempt_schedule_notrace_dynamic_enabled preempt_schedule_notrace_thunk +#define preempt_schedule_notrace_dynamic_disabled NULL #ifdef CONFIG_PREEMPT_DYNAMIC -DECLARE_STATIC_CALL(preempt_schedule, __preempt_schedule_func); +DECLARE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled); #define __preempt_schedule() \ do { \ @@ -125,7 +127,7 @@ do { \ asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule) : ASM_CALL_CONSTRAINT); \ } while (0) -DECLARE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func); +DECLARE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled); #define __preempt_schedule_notrace() \ do { \ diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index 2e2b8d6140ed..a01ac1a0a292 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -456,6 +456,8 @@ irqentry_state_t noinstr irqentry_enter(struct pt_regs *regs); */ void irqentry_exit_cond_resched(void); #ifdef CONFIG_PREEMPT_DYNAMIC +#define irqentry_exit_cond_resched_dynamic_enabled irqentry_exit_cond_resched +#define irqentry_exit_cond_resched_dynamic_disabled NULL DECLARE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); #endif diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6e8998267102..414165c430f4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6489,7 +6489,11 @@ NOKPROBE_SYMBOL(preempt_schedule); EXPORT_SYMBOL(preempt_schedule); #ifdef CONFIG_PREEMPT_DYNAMIC -DEFINE_STATIC_CALL(preempt_schedule, __preempt_schedule_func); +#ifndef preempt_schedule_dynamic_enabled +#define preempt_schedule_dynamic_enabled preempt_schedule +#define preempt_schedule_dynamic_disabled NULL +#endif +DEFINE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled); EXPORT_STATIC_CALL_TRAMP(preempt_schedule); #endif @@ -6547,7 +6551,11 @@ 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); +#ifndef preempt_schedule_notrace_dynamic_enabled +#define preempt_schedule_notrace_dynamic_enabled preempt_schedule_notrace +#define preempt_schedule_notrace_dynamic_disabled NULL +#endif +DEFINE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled); EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace); #endif @@ -8058,9 +8066,13 @@ EXPORT_SYMBOL(__cond_resched); #endif #ifdef CONFIG_PREEMPT_DYNAMIC +#define cond_resched_dynamic_enabled __cond_resched +#define cond_resched_dynamic_disabled ((void *)&__static_call_return0) DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched); EXPORT_STATIC_CALL_TRAMP(cond_resched); +#define might_resched_dynamic_enabled __cond_resched +#define might_resched_dynamic_disabled ((void *)&__static_call_return0) DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched); EXPORT_STATIC_CALL_TRAMP(might_resched); #endif @@ -8184,43 +8196,46 @@ int sched_dynamic_mode(const char *str) return -EINVAL; } +#define preempt_dynamic_enable(f) static_call_update(f, f##_dynamic_enabled) +#define preempt_dynamic_disable(f) static_call_update(f, f##_dynamic_disabled) + void sched_dynamic_update(int mode) { /* * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in * the ZERO state, which is invalid. */ - static_call_update(cond_resched, __cond_resched); - static_call_update(might_resched, __cond_resched); - static_call_update(preempt_schedule, __preempt_schedule_func); - static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); - static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); + preempt_dynamic_enable(cond_resched); + preempt_dynamic_enable(might_resched); + preempt_dynamic_enable(preempt_schedule); + preempt_dynamic_enable(preempt_schedule_notrace); + preempt_dynamic_enable(irqentry_exit_cond_resched); switch (mode) { case preempt_dynamic_none: - static_call_update(cond_resched, __cond_resched); - static_call_update(might_resched, (void *)&__static_call_return0); - static_call_update(preempt_schedule, NULL); - static_call_update(preempt_schedule_notrace, NULL); - static_call_update(irqentry_exit_cond_resched, NULL); + preempt_dynamic_enable(cond_resched); + preempt_dynamic_disable(might_resched); + preempt_dynamic_disable(preempt_schedule); + preempt_dynamic_disable(preempt_schedule_notrace); + preempt_dynamic_disable(irqentry_exit_cond_resched); pr_info("Dynamic Preempt: none\n"); break; case preempt_dynamic_voluntary: - static_call_update(cond_resched, __cond_resched); - static_call_update(might_resched, __cond_resched); - static_call_update(preempt_schedule, NULL); - static_call_update(preempt_schedule_notrace, NULL); - static_call_update(irqentry_exit_cond_resched, NULL); + preempt_dynamic_enable(cond_resched); + preempt_dynamic_enable(might_resched); + preempt_dynamic_disable(preempt_schedule); + preempt_dynamic_disable(preempt_schedule_notrace); + preempt_dynamic_disable(irqentry_exit_cond_resched); pr_info("Dynamic Preempt: voluntary\n"); break; case preempt_dynamic_full: - static_call_update(cond_resched, (void *)&__static_call_return0); - static_call_update(might_resched, (void *)&__static_call_return0); - static_call_update(preempt_schedule, __preempt_schedule_func); - static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); - static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); + preempt_dynamic_disable(cond_resched); + preempt_dynamic_disable(might_resched); + preempt_dynamic_enable(preempt_schedule); + preempt_dynamic_enable(preempt_schedule_notrace); + preempt_dynamic_enable(irqentry_exit_cond_resched); pr_info("Dynamic Preempt: full\n"); break; } -- 2.30.2