From nobody Fri Sep 12 08:32:23 2025 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 1241AC001E0 for ; Wed, 9 Aug 2023 22:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232504AbjHIWND (ORCPT ); Wed, 9 Aug 2023 18:13:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229765AbjHIWM4 (ORCPT ); Wed, 9 Aug 2023 18:12:56 -0400 Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DE49FE for ; Wed, 9 Aug 2023 15:12:54 -0700 (PDT) Received: by mail-qt1-f175.google.com with SMTP id d75a77b69052e-40fd2de0ddcso1401881cf.2 for ; Wed, 09 Aug 2023 15:12:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691619173; x=1692223973; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=my7KvWpBax07SiFGA75jMeAqtWUxF1Y/C+Nl9uBqALw=; b=d6tpVQEJIhqG9INdfyZos7vupdpaTkItOGIyhMhDu/fmZjhO+0lo2Nd33IH1QuWBPQ ZajP98eUKRPyRPEJEwzoS7mQ8/xV8MOlW2viOYSV1FJ8+D+AFDd6y0iBOr/AVd618BsP IXyDtQ1GepZWHd55LMj0ZLtf/cW8z5UTswKDhbSt3aC5Zc7wOq0Zz/DZbQZaQwE4fJRq 80xa1rPKGGePektULh0hygle/n3ey6wCAfsYbdv9g/AH+rUdQl6pxbS3ckI4ou22Et7J 2rHVFDH2cpg0PdbwHfsZLhuYdwjjpYOL100tJxx8ovgsoGPTYAsO/m9xv+adHlHakJxW CfsA== X-Gm-Message-State: AOJu0Yz6WewfQ/78K2ArblfyupdpKBv5xIne2l4HYda5y2A2yNyU0P+L T+e1gml6z2tJM49LQmdejFlLdUVvWetmX68s X-Google-Smtp-Source: AGHT+IEhS7+dHkIMTLR7HLmTiHfjdlJJaZQ6ts8Yn+4aufQCuVeXCecsX1btMZJvJglWa9RgWg8J4A== X-Received: by 2002:a05:622a:153:b0:403:c3cd:d7c3 with SMTP id v19-20020a05622a015300b00403c3cdd7c3mr736588qtw.50.1691619172985; Wed, 09 Aug 2023 15:12:52 -0700 (PDT) Received: from localhost ([2620:10d:c091:400::5:ed08]) by smtp.gmail.com with ESMTPSA id c17-20020ac80091000000b003ff1f891206sm38648qtg.61.2023.08.09.15.12.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Aug 2023 15:12:52 -0700 (PDT) From: David Vernet To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, tj@kernel.org, roman.gushchin@linux.dev, gautham.shenoy@amd.com, kprateek.nayak@amd.com, aaron.lu@intel.com, wuyun.abel@bytedance.com, kernel-team@meta.com Subject: [PATCH v3 4/7] sched: Enable sched_feat callbacks on enable/disable Date: Wed, 9 Aug 2023 17:12:15 -0500 Message-ID: <20230809221218.163894-5-void@manifault.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809221218.163894-1-void@manifault.com> References: <20230809221218.163894-1-void@manifault.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When a scheduler feature is enabled or disabled, the sched_feat_enable() and sched_feat_disable() functions are invoked respectively for that feature. For features that don't require resetting any state, this works fine. However, there will be an upcoming feature called shared_runq which needs to drain all tasks from a set of global shared runqueues in order to avoid stale tasks from staying in the queues after the feature has been disabled. This patch therefore defines a new SCHED_FEAT_CALLBACK macro which allows scheduler features to specify a callback that should be invoked when a feature is enabled or disabled respectively. The SCHED_FEAT macro assumes a NULL callback. Signed-off-by: David Vernet --- kernel/sched/core.c | 4 ++-- kernel/sched/debug.c | 18 ++++++++++++++---- kernel/sched/sched.h | 16 ++++++++++------ 3 files changed, 26 insertions(+), 12 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index dd6412a49263..385c565da87f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -124,12 +124,12 @@ DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); * sysctl_sched_features, defined in sched.h, to allow constants propagati= on * at compile time and compiler optimization based on features default. */ -#define SCHED_FEAT(name, enabled) \ +#define SCHED_FEAT_CALLBACK(name, enabled, cb) \ (1UL << __SCHED_FEAT_##name) * enabled | const_debug unsigned int sysctl_sched_features =3D #include "features.h" 0; -#undef SCHED_FEAT +#undef SCHED_FEAT_CALLBACK =20 /* * Print a warning if need_resched is set for the given duration (if diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index aeeba46a096b..803dff75c56f 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -44,14 +44,14 @@ static unsigned long nsec_low(unsigned long long nsec) =20 #define SPLIT_NS(x) nsec_high(x), nsec_low(x) =20 -#define SCHED_FEAT(name, enabled) \ +#define SCHED_FEAT_CALLBACK(name, enabled, cb) \ #name , =20 static const char * const sched_feat_names[] =3D { #include "features.h" }; =20 -#undef SCHED_FEAT +#undef SCHED_FEAT_CALLBACK =20 static int sched_feat_show(struct seq_file *m, void *v) { @@ -72,22 +72,32 @@ static int sched_feat_show(struct seq_file *m, void *v) #define jump_label_key__true STATIC_KEY_INIT_TRUE #define jump_label_key__false STATIC_KEY_INIT_FALSE =20 -#define SCHED_FEAT(name, enabled) \ +#define SCHED_FEAT_CALLBACK(name, enabled, cb) \ jump_label_key__##enabled , =20 struct static_key sched_feat_keys[__SCHED_FEAT_NR] =3D { #include "features.h" }; =20 -#undef SCHED_FEAT +#undef SCHED_FEAT_CALLBACK + +#define SCHED_FEAT_CALLBACK(name, enabled, cb) cb, +static const sched_feat_change_f sched_feat_cbs[__SCHED_FEAT_NR] =3D { +#include "features.h" +}; +#undef SCHED_FEAT_CALLBACK =20 static void sched_feat_disable(int i) { + if (sched_feat_cbs[i]) + sched_feat_cbs[i](false); static_key_disable_cpuslocked(&sched_feat_keys[i]); } =20 static void sched_feat_enable(int i) { + if (sched_feat_cbs[i]) + sched_feat_cbs[i](true); static_key_enable_cpuslocked(&sched_feat_keys[i]); } #else diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 88cca7cc00cf..2631da3c8a4d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2065,6 +2065,8 @@ static inline void __set_task_cpu(struct task_struct = *p, unsigned int cpu) #endif } =20 +#define SCHED_FEAT(name, enabled) SCHED_FEAT_CALLBACK(name, enabled, NULL) + /* * Tunables that become constants when CONFIG_SCHED_DEBUG is off: */ @@ -2074,7 +2076,7 @@ static inline void __set_task_cpu(struct task_struct = *p, unsigned int cpu) # define const_debug const #endif =20 -#define SCHED_FEAT(name, enabled) \ +#define SCHED_FEAT_CALLBACK(name, enabled, cb) \ __SCHED_FEAT_##name , =20 enum { @@ -2082,7 +2084,7 @@ enum { __SCHED_FEAT_NR, }; =20 -#undef SCHED_FEAT +#undef SCHED_FEAT_CALLBACK =20 #ifdef CONFIG_SCHED_DEBUG =20 @@ -2093,14 +2095,14 @@ enum { extern const_debug unsigned int sysctl_sched_features; =20 #ifdef CONFIG_JUMP_LABEL -#define SCHED_FEAT(name, enabled) \ +#define SCHED_FEAT_CALLBACK(name, enabled, cb) \ static __always_inline bool static_branch_##name(struct static_key *key) \ { \ return static_key_##enabled(key); \ } =20 #include "features.h" -#undef SCHED_FEAT +#undef SCHED_FEAT_CALLBACK =20 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x= ])) @@ -2118,17 +2120,19 @@ extern struct static_key sched_feat_keys[__SCHED_FE= AT_NR]; * constants propagation at compile time and compiler optimization based on * features default. */ -#define SCHED_FEAT(name, enabled) \ +#define SCHED_FEAT_CALLBACK(name, enabled, cb) \ (1UL << __SCHED_FEAT_##name) * enabled | static const_debug __maybe_unused unsigned int sysctl_sched_features =3D #include "features.h" 0; -#undef SCHED_FEAT +#undef SCHED_FEAT_CALLBACK =20 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) =20 #endif /* SCHED_DEBUG */ =20 +typedef void (*sched_feat_change_f)(bool enabling); + extern struct static_key_false sched_numa_balancing; extern struct static_key_false sched_schedstats; =20 --=20 2.41.0