From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.128.41 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794242184; b=uaOucyjv2o2YIEzOWmwNY1aOUvigoSyiefjU4f11UGRLdyb3F5CEIW255UWQ4msaZIC1 asu1J0msekeno6DptKpFqV1nvXf4UjbNEzRkC4m+gTlMySbkXdGWTPiOrH1s1DD3Bril+ SYX3RBXS5H9kVr9R5ZuOXw+tMdONAY5sROHVXV15rTtHVnfhHouWPC7WWuanQT/tI6FLv k63Fx7Q1An6Mq8ce90RZ9uMmAQTDs2SXL94fLU6W1k5sAv4+jXEKBa7cM/UIiEAtF/u5A GLTuO6pT5c9HxgpzAy+E2jidIsT2Jwprium1QwKAt7kLQ2RsntcIT3wIpUn56hCeYzA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794242184; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Gm-Message-State:X-Gm-Gg:X-Received:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=SpFA5SgbZJhb9ponpVrLzGNwdHqcbHvWyklpgw1Qw5A=; b=2kODbT7BoKnQwKGzxfXhlv+txD+kRk+3RKx9C4psHvAqkK0hsudKE/uclsVlGGpMqLVg gukbPWW5XWKydyPHwjMGkpvxvBk7h2fMZIizwYljD7ncQc+u/P/9K9DNWNH6FrhDLvXRb DgVTPqPE9wdzWOSHIgOaWU/lIFJQVzNraH3XBP2tnEZJQoNiuEtQpACTgLYG79ULGfcZx +ZiMMXJ6PgqSQGTW8w8XDMeLHzu8ODMLRCa6IDIwG4yIGFrPaXEOeI7FoEV9v/ZTlt4zq lrGTtoxFGPItj690zLyQOtqzvgEZMiHP/MudnU+OphZsTpV1lR292OeOsZaw9/XJ5BQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=E5SJX+2f; arc=none smtp.remote-ip=209.85.128.41 Received: from mail-wm1-f41.google.com (mail-wm1-f41.google.com [209.85.128.41]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CBA27606A330 for ; Mon, 9 Nov 2026 16:36:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org CBA27606A330 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=E5SJX+2f Received: by mail-wm1-f41.google.com with SMTP id 5b1f17b1804b1-4a215e64962so12847325e9.1 for ; Mon, 09 Nov 2026 08:36:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794242182; x=1794846982; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=SpFA5SgbZJhb9ponpVrLzGNwdHqcbHvWyklpgw1Qw5A=; b=E5SJX+2ff3/h5onmzPB9GjihmE2+6WLp9hzZVK2hbtsAvbPrD7WJIJTpgNbLJycJ8t j3MBBCvHxsQRvltiTSiGyf2ajMBRLmuTAL22CUZZwLOaxn4TZ48N7ieg8yc+jN2O0Ci9 pYl4B4s/t5Erxyx56M0KuaEX7NOLFw5AM9xLQplgrFcFJhLrCDsCtSgmTZPh6ohVOkuR XgQZYDizOplKlNqjDfoKwuGZRxaixXGBP+l+RpiVefC6J04bHRAULMt9HLSe7PwH2Yxe H4rAgut2QvQB/qiGo8/cHuI+O/uxgunk0Rj4846WBCQrEKIchLyZRmSY9fmigmL+VGDm chUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794242182; x=1794846982; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=SpFA5SgbZJhb9ponpVrLzGNwdHqcbHvWyklpgw1Qw5A=; b=xcYZ+I8Efe2BM2g+xajhopJi2Wq6J/MPBSToaRZO4DK0/L9C2AxLyaJwTaFYr9o419 +NsJwWGT56PrckC2t3YNZT3tP1SwkmnyCpeeHD0is3rseEhPsB3DWF1OKhkp45Ax844y Jx/xRmNArUCwO7bHqgv3ikvWshxlLucEKMuccF1xDpoo3VdlbgcoD4GcPXWmvU6+lmwS PYkRED9tQrIZs6Zx52emBi37axx8xtdzn9G8R637Zip4vQb1hzhEslrzkf7KG9gPSuvm tK4V6cq92IwyNuiZqysiLYbAPKmOAuNTOJWcn1oPXpDAD61Uk1/ASaQPpn+BL2chc3rK N8Tg== X-Gm-Message-State: APuU4Z8io2axgTOJ0uTcVET2JUwNR3Q/7thIyBl4+rzW9Ucx0HlFpCQl wfRD6jgzmgUyUjLzfB4Gf1E5UGoG/mQqRurBZvXZq3vHclwbUm0ilbYI X-Gm-Gg: AYBFou12yLcQus90ukRhzkS9KZA3K3dQpF6SO64RKZTMXDmXsBC39DNo96XNnV+XiTu r2JwMMocUMIbX/ooZxKuWrwu6RY5aL0E9QIFN4OwyIvWfXSgbQ7kAQmddqNUxLnVSdEOzQP5wEF 4KU4pelbj7smh1TBIqAM3Y9oLEYU1qSrPDG2w2tybz/xLHOT4NbB+7lGcJtrwILOToJ2JagAaVC QGD6G8/Nlg3q8FkpNr/7ctupH4TnGUAZCkNKh/+Z10ZlTYetPzSatTjaTDlTUP1JDZqFgEtvDBP gCdNIznFACPNC4ap4ESL01Vl1loxXE4xBWlpQfDvP4T5EGir59qhXcQbLRXn4Tqv6uYKSTtusvl ttONZTRjKIvnB4RkuS/RHO5pKVj7WReGlOjwN/ZN3IEij3V7QlT8MABbqPGW5EhtvFC6JXKCcwC N9+/hIgLTYymEaEJeLOYKL9SeuMNbCzP0gEu5/rOAuuPe8sGz6LrWXeoAjF5BsZVMyj4gUoTk/T nPbMHbmGVlI9BejXRIkvpRcjabZTSPVM/Xo8ObPmtOOec+1VBRBA745YwKD3UqHRBHsK9/hqWx8 L0nEfYFbrMJAYmtzkWQqBMjH5lDDRyNP+Y7Qb34h4aE33vU= X-Received: by 2002:a05:600c:8712:b0:4b1:2026:6b41 with SMTP id 5b1f17b1804b1-4b963c9de56mr86531255e9.30.1794242182232; Mon, 09 Nov 2026 08:36:22 -0800 (PST) Received: from victus-lab ([193.205.81.5]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4b96cd012e1sm138851295e9.8.2026.11.09.08.36.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Nov 2026 08:36:21 -0800 (PST) From: Yuri Andriaccio To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Abeni , Yuri Andriaccio Subject: [RFC PATCH v7 01/29] sched/deadline: Introduce dl_freq_invariant flag for fair/ext servers Date: Mon, 9 Nov 2026 17:35:47 +0100 Message-ID: <20261109163616.195264-2-yurand2000@gmail.com> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261109163616.195264-1-yurand2000@gmail.com> References: <20261109163616.195264-1-yurand2000@gmail.com> X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The fair/ext servers are by design frequency and capacity invariant, i.e. their maximum allowed runtime is fixed, regardless of the frequency the CPU is running. (See also https://lore.kernel.org/all/20250702021440.2594736-1-kuyo.chang@mediatek.com/) This inevitably broke non-fair dl_servers, which would want to instead scale their execution time to be consistent with CBS and GRUB-PA. The newly added flag allows deadline servers to adopt the frequency invariance behaviour as fair/ext servers. Signed-off-by: Yuri Andriaccio --- include/linux/sched.h | 4 ++++ kernel/sched/deadline.c | 5 ++++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 1c93da75226e..b78ca828f694 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -706,6 +706,9 @@ struct sched_dl_entity { * contributes to the root domain's total_bw. Only meaningful for server * entities (@dl_server == 1). Allows toggling the reservation on/off * without losing the configured @dl_runtime/@dl_period. + * + * @dl_freq_invariant tells if this server's runtime must NOT be scaled + * by the CPU's frequency and capacity. */ unsigned int dl_throttled : 1; unsigned int dl_yielded : 1; @@ -718,6 +721,7 @@ struct sched_dl_entity { unsigned int dl_defer_running : 1; unsigned int dl_defer_idle : 1; unsigned int dl_bw_attached : 1; + unsigned int dl_freq_invariant : 1; /* * Bandwidth enforcement timer. Each -deadline task has its diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index c0ebdcde5fe5..57c7a8802d8e 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1432,7 +1432,7 @@ static void update_curr_dl_se(struct rq *rq, struct sched_dl_entity *dl_se, s64 return; scaled_delta_exec = delta_exec; - if (!dl_server(dl_se)) + if (!dl_server(dl_se) || !dl_se->dl_freq_invariant) scaled_delta_exec = dl_scaled_delta_exec(rq, dl_se, delta_exec); dl_se->runtime -= scaled_delta_exec; @@ -1862,6 +1862,7 @@ void sched_init_dl_servers(void) dl_se->dl_server = 1; dl_se->dl_defer = 1; + dl_se->dl_freq_invariant = 1; setup_new_dl_entity(dl_se); #ifdef CONFIG_SCHED_CLASS_EXT @@ -1873,6 +1874,7 @@ void sched_init_dl_servers(void) dl_se->dl_server = 1; dl_se->dl_defer = 1; + dl_se->dl_freq_invariant = 1; setup_new_dl_entity(dl_se); /* @@ -3957,6 +3959,7 @@ static void __dl_clear_params(struct sched_dl_entity *dl_se) dl_se->dl_defer = 0; dl_se->dl_defer_running = 0; dl_se->dl_defer_armed = 0; + dl_se->dl_freq_invariant = 0; #ifdef CONFIG_RT_MUTEXES dl_se->pi_se = dl_se; -- 2.56.0