From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48157372B27 for ; Fri, 24 Jul 2026 18:12:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784916774; cv=none; b=ipnoJ34L7qQeeuF+Xr7oUGk9B5ysBv0fTAU/2jwCm+DICdkw2cb7GILZ5B868BDpGDmjMoQc2AYk5QM/3ghn6ApHmENZ6RBGpPQFxJtXNHVCz0d7k05nfEGLeRhp4KCtGHVC11fp6/5ExcpbPFLhA7iRPGK7HQlkxKwIeQvEq0k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784916774; c=relaxed/simple; bh=OqJ39F9aEBeNkacHvljqDrKwYBAVIL2tWzg9ofeIMJI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=c1DMAQMiWT5hSc2W9vxUnmwLtFw3xlX5Y8j9py8Dt4vdkZa85+N0Iu3u8no9wLsfMMuAEpzpkER4gMFJHWvh/HuIv3AFIYz7Ft5MMi3e4Mqd/8xNjV7S5dip2wk5Rumiq9NSoEnuwmnKjet189dSVoCi/3vUC4e2fzrfDWtD9W4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GtwD98yL; arc=none smtp.client-ip=209.85.210.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GtwD98yL" Received: by mail-pf1-f197.google.com with SMTP id d2e1a72fcca58-84842381150so1087749b3a.3 for ; Fri, 24 Jul 2026 11:12:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784916770; x=1785521570; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=kWbB0NWfOkfjR5Zf1PJALEvxKOiKfMCKTW3apXjrlUY=; b=GtwD98yLOEDzHdjkk85SV26UPEBIWT0faexhv8GyGiYs346LqllGmpiqY/ekfT1TXL 0Z6QBJVUb1ed2zrINCBHLX4y/g1PeuxIPXK3CZu1QZFdeefeArH0KVfPoQknIteBvkjC TQJM+9g4K5HAkwQkhTWV+wbANBdAHnFdlwZah79x9igS9jSqy51LOZR33HjSQyYzUjwq 6XWv7s+GaTOBR5DS1u0n1EcRJtmVZiyFDYgEcghGEAHGNAjIrCAVs5kcpOjnTbKGR2Mp CjGET/mr08s85xaylxTCRx1kp73IuZJFZGvqyV2sUFPB1PH7l2ZbNJmmh3ppc6C2CtaI v5nA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784916770; x=1785521570; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=kWbB0NWfOkfjR5Zf1PJALEvxKOiKfMCKTW3apXjrlUY=; b=dqwjZQ3nfnlsGfaTApElLxKbqLaNAD79ma2HD+nhH0pACYvkIICYENtqn/BXY8KMEw P8MHnAnQ8/imVAw+xZU8mcSEiOt4G7zh/NwyPZnSxzMscLymu3AeLMAKv5KKy756iAFU qqCJ36odf/KbfIdrRXp9XjQZWQoMWx2PbTx+f92BfNbfwKLctcLQ6lXvtrTdWsIb32Ua dpvbJxDPLz2t25FCK+MewyxNLIk/SXRqRfe29tS+dwv9gn+yYAju30ZRF5Un/WybWQRT R69SEmFIzZZbx3ZLcHmDb7ih4+EShIWW6Rqw93XkTmxwmVSOaGX7MLLBhq8xSH2dkJuU UqeQ== X-Gm-Message-State: AOJu0YwaaQ5amdJWJpWRFBw87webi6VxngBFPMyUg6/uQ2EgGY31W1tM cm4H+7o79d/TknUlyIME1K/txilGXW1HSt3xOxi9dssJMngcs7hTlC+HOR9+9YbiZomBLL5xnQN T/w+WQ+Wkkdm7PI4Y3rSJRre8Pbs9qiUiY28C9keYQq7fnMqZGyVGvIHH0RSFlCO76qdqIxxO4J 7V1awwm0Ihr6Q/7eB5wPpYDrIhB6G7oyY0+KKz3lAeMB3aqqBd X-Received: from pfbhq5.prod.google.com ([2002:a05:6a00:6805:b0:848:416d:e7f3]) (user=jstultz job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:4b56:b0:84e:538:476c with SMTP id d2e1a72fcca58-84e2bbf9189mr8753440b3a.67.1784916769747; Fri, 24 Jul 2026 11:12:49 -0700 (PDT) Date: Fri, 24 Jul 2026 18:12:23 +0000 In-Reply-To: <20260724181238.3445275-1-jstultz@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260724181238.3445275-1-jstultz@google.com> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog Message-ID: <20260724181238.3445275-10-jstultz@google.com> Subject: [PATCH v31 9/9] sched: Distinguish proxy activations from wakeups From: John Stultz To: LKML Cc: Andrea Righi , John Stultz , Joel Fernandes , Qais Yousef , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Valentin Schneider , Steven Rostedt , Ben Segall , Zimuzo Ezeozue , Mel Gorman , Will Deacon , Waiman Long , Boqun Feng , "Paul E. McKenney" , Metin Kaya , Xuewen Yan , K Prateek Nayak , Thomas Gleixner , Daniel Lezcano , Suleiman Souhlal , kuyo chang , hupu , kernel-team@android.com Content-Type: text/plain; charset="UTF-8" From: Andrea Righi Sleeping-owner handling reactivates blocked waiters with wakeup enqueue semantics so scheduling classes can restore their runnable accounting. Unlike a normal wakeup, the waiter remains blocked and is only made runnable to donate its scheduling context. Add ENQUEUE_PROXY to identify this activation and set it alongside ENQUEUE_WAKEUP. Consume the internal marker in sched_ext and suppress SCX_ENQ_WAKEUP before invoking BPF so the activation can be handled as a blocked proxy donor. Signed-off-by: Andrea Righi Signed-off-by: John Stultz --- Cc: Joel Fernandes Cc: Qais Yousef Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Valentin Schneider Cc: Steven Rostedt Cc: Ben Segall Cc: Zimuzo Ezeozue Cc: Mel Gorman Cc: Will Deacon Cc: Waiman Long Cc: Boqun Feng Cc: "Paul E. McKenney" Cc: Metin Kaya Cc: Xuewen Yan Cc: K Prateek Nayak Cc: Thomas Gleixner Cc: Daniel Lezcano Cc: Suleiman Souhlal Cc: Andrea Righi Cc: kuyo chang Cc: hupu Cc: kernel-team@android.com --- kernel/sched/core.c | 2 +- kernel/sched/ext/ext.c | 8 ++++++++ kernel/sched/sched.h | 2 ++ 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d813a9c2f0c35..c54e9fedc9cd8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3900,7 +3900,7 @@ static void activate_blocked_waiters(struct rq *target_rq, { struct list_head bal_head; unsigned long flags; - int en_flags = ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK; + int en_flags = ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK | ENQUEUE_PROXY; if (!sched_proxy_exec()) return; diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index e3fa7b2fac9df..834c8b6dae6c9 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -2021,6 +2021,14 @@ static void enqueue_task_scx(struct rq *rq, struct task_struct *p, int core_enq_ int sticky_cpu = p->scx.sticky_cpu; u64 enq_flags = core_enq_flags | rq->scx.extra_enq_flags; + /* + * Sleeping-owner activation uses wakeup semantics for the core + * scheduling classes, but the donor remains blocked. Expose it to BPF + * as a blocked-donor admission rather than a full wakeup. + */ + if (core_enq_flags & ENQUEUE_PROXY) + enq_flags &= ~(ENQUEUE_PROXY | SCX_ENQ_WAKEUP); + if (enq_flags & ENQUEUE_WAKEUP) rq->scx.flags |= SCX_RQ_IN_WAKEUP; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 56d9c09c485e6..e38988574cfa2 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2540,6 +2540,7 @@ extern const u32 sched_prio_to_wmult[40]; * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) * ENQUEUE_MIGRATED - the task was migrated during wakeup * ENQUEUE_RQ_SELECTED - ->select_task_rq() was called + * ENQUEUE_PROXY - activate a blocked donor behind a waking owner * * XXX SAVE/RESTORE in combination with CLASS doesn't really make sense, but * SCHED_DEADLINE seems to rely on this for now. @@ -2571,6 +2572,7 @@ extern const u32 sched_prio_to_wmult[40]; #define ENQUEUE_MIGRATED 0x00040000 #define ENQUEUE_INITIAL 0x00080000 #define ENQUEUE_RQ_SELECTED 0x00100000 +#define ENQUEUE_PROXY 0x00200000 #define RETRY_TASK ((void *)-1UL) -- 2.55.0.229.g6434b31f56-goog