From nobody Sun Feb 8 23:35:12 2026 Received: from mail-ot1-f42.google.com (mail-ot1-f42.google.com [209.85.210.42]) (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 EC7CD15623B for ; Sat, 17 Aug 2024 20:46:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723927610; cv=none; b=RkNin+PDIerCqVgv0aNKhSUl4oIUxtE/EPEjYdz/wC/34fDN1X13r+ddE3jcKo4BzW6ClGCAkOYSxPFfSK794UvXc5YR8k5dkMaTuMg4r07GFEMdcm0XNqC4XSYRZYOkdQqwvb5u7qQL97OsQZdVQhEa9ZpUrIe/f55Jbi/LeZY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723927610; c=relaxed/simple; bh=7Vp7No9whTj/vA4D1O3CqTZTNcenrkvZwi9JHFy5Tm8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lva8ToINsf44yRFb/KUGgSLVH4iK8DTeyyxwbz9mBLkCMtCxSiTq2x31pLGxejSzx+1VPiQFt7Qz9KH+94iR422hA4V+mho3opgB6zRO+hJ5ZDO40MkZ97vNuZErjpDStVFRm5AJswFheaJtHZ1D0derIOoHPmG2phjlGaeBVAo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=kyjbiwa1; arc=none smtp.client-ip=209.85.210.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="kyjbiwa1" Received: by mail-ot1-f42.google.com with SMTP id 46e09a7af769-70c7c5cb313so48589a34.1 for ; Sat, 17 Aug 2024 13:46:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1723927606; x=1724532406; 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; bh=02y/Wd8d3ZrLXS7qBzEKtx51SdWa+9oNHCqY9s5SPZE=; b=kyjbiwa1Y0r0vy7Jqzp9b3DNujVInGrqgtIPLPYMs0lJSEf1Bum4in7Mwk7xYO4oA7 PTX6dOynrg+Nd4c9CvWHzjrxNtH8zU5CFxwVDATRXFC0X22W5xLUAkbAOYEsDeh+Jf8h O+0uFZNXmAc30iqRE31snyCj+Ut07YF0A3KTN5U+cJzELey2WGtmyFw3AfVvBx5a3aGo R6pOtLnML//iji/4p7dLWqdYYEGNbaHK9WCJ1mWyRB8Jh49CVCEfuXTUFZF4fwoMerKM TmIadzgCLvmlHf1uKyURjyiGIdDm99rvDztyNXd76FGfTaXX/dMGrRLDYwAwfNH4hhJe x7HQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723927606; x=1724532406; 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=02y/Wd8d3ZrLXS7qBzEKtx51SdWa+9oNHCqY9s5SPZE=; b=A5vGeVdhLOY9Yb4aDnsmppiFXtWQ5XKWUBPtrladSo/I1L1aql/cnXM7FXbqCopcGL 6iE9M2coSFX0tKtZXnX+8ZmXDIQuOWZBtOD/fn749n/nNDiZVjqMuDG2qNGxx31bLeuB Ve9H+kYolqGc2J4xn3EXikSNLL3Byy0pjKyb5N5v149vFirEbqGzGhnQfEed/ftsXFAZ dqCXNHRkJ3tyauKI7aEv/dyN1SF/aTqbz0JYUp9jYlzf6Z4ucTqg2qNBMEwCKOBnMEb8 8ebuCgTbCLNUOZDyTNNxosjPbB2SjaQEKdhX/csTM/LtI9BqG1BszsEcCc148ulVt95j mBIA== X-Gm-Message-State: AOJu0YymL8X4x3KHkf88Gtu2+zXElKuR+4uDzbXiVqPwJG8cGbYAfFjA XY9fohYFVMIluTLrJJV1lvFy/3n4vu3xmBfmVgOijOFP7iXF8r+hMbVS2ijwwb/Vhi08PvZlJF6 O X-Google-Smtp-Source: AGHT+IFqjfiTlMbyBgbOXSrDzwrVTU0Iq7cMM59EJVaPUwdJqLY9FKlS5uF3LRTNIbPXN3Rw+6xIRw== X-Received: by 2002:a05:6830:4486:b0:703:78ff:1e1 with SMTP id 46e09a7af769-70cac7d4d86mr3074352a34.0.1723927606580; Sat, 17 Aug 2024 13:46:46 -0700 (PDT) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7127ae07e41sm4411039b3a.65.2024.08.17.13.46.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 17 Aug 2024 13:46:45 -0700 (PDT) From: Jens Axboe To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, tglx@linutronix.de, Jens Axboe Subject: [PATCH 2/4] sched/core: change rq->nr_iowait type to atomic_long_t on 64-bit Date: Sat, 17 Aug 2024 14:45:11 -0600 Message-ID: <20240817204639.132794-3-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240817204639.132794-1-axboe@kernel.dk> References: <20240817204639.132794-1-axboe@kernel.dk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In preparation for storing two separate iowait states in there, bump the size from a 32-bit to a 64-bit size, for 64-bit kernels. Note that on 32-bit, the number of tasks are limited to 0x8000, which fits just fine in even half of the existiing 32-bit atomic_t. For 64-bit, no such limit exists, hence play it safe and make it a 64-bit atomic. Signed-off-by: Jens Axboe --- kernel/sched/core.c | 14 +++++++++++++- kernel/sched/sched.h | 4 ++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9bf1b67818d0..ddabf20cd9e0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3543,17 +3543,29 @@ static inline bool rq_has_pinned_tasks(struct rq *r= q) =20 static void task_iowait_inc(struct task_struct *p) { +#ifdef CONFIG_64BIT + atomic_long_inc(&task_rq(p)->nr_iowait); +#else atomic_inc(&task_rq(p)->nr_iowait); +#endif } =20 static void task_iowait_dec(struct task_struct *p) { +#ifdef CONFIG_64BIT + atomic_long_dec(&task_rq(p)->nr_iowait); +#else atomic_dec(&task_rq(p)->nr_iowait); +#endif } =20 int rq_iowait(struct rq *rq) { +#ifdef CONFIG_64BIT + return atomic_long_read(&rq->nr_iowait); +#else return atomic_read(&rq->nr_iowait); +#endif } =20 static void @@ -8372,7 +8384,7 @@ void __init sched_init(void) #endif #endif /* CONFIG_SMP */ hrtick_rq_init(rq); - atomic_set(&rq->nr_iowait, 0); + atomic_long_set(&rq->nr_iowait, 0); fair_server_init(rq); =20 #ifdef CONFIG_SCHED_CORE diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b6b3b565bcb1..6a90c2da1eb3 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1082,7 +1082,11 @@ struct rq { u64 clock_idle_copy; #endif =20 +#ifdef CONFIG_64BIT + atomic_long_t nr_iowait; +#else atomic_t nr_iowait; +#endif =20 #ifdef CONFIG_SCHED_DEBUG u64 last_seen_need_resched_ns; --=20 2.43.0