From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (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 1D5D43BBFB2 for ; Mon, 15 Jun 2026 07:40:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781509250; cv=none; b=YCruOG2k45cKV0vMLpPxKlwnDBhFCyEXyBXCIhSnD6z+Emq8q/QJmVE1SDe5KENTQEXasmu58rR5gfo65Ojjpg89ng9Ftr2f/rbpRGSMe6jXRzWlYg8LCRHSx6bhdQwQmV+JqhOfYCwyNOG5VLpNbnd3fRzbfe9nf92MMY9lpZ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781509250; c=relaxed/simple; bh=7gTGoROcY88FIx0BKI9qz9m4P1KC5KNO+9LCkMExk6Q=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=epfk81Km/VWft3oq6bNIEMlYdTrCmg1ppBawAJ268fvgblZsVLcuZHjRfHLhZzSypRtltbSdMTfTcE6QKkF9oTc6ex9DauSpto5ekequ7s6obbE2vbRAEAe/+fh84Kaoqg5rZU054q6G4GOov6dtLARuMuctUMtQWQOqwW+8Sdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=JWp/+HCa; arc=none smtp.client-ip=209.85.218.45 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.b="JWp/+HCa" Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-beb2a97cc9aso562350066b.2 for ; Mon, 15 Jun 2026 00:40:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781509247; x=1782114047; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=7gTGoROcY88FIx0BKI9qz9m4P1KC5KNO+9LCkMExk6Q=; b=JWp/+HCaUhyEnt2o/PJZ0btNxmB7yrbB5dHGBysqFYgc2VBD60QKSDWlMKZdI73pmN 2FEqtzYk+DAU/Ns/Hfgp/Fgbzap7TfDGfXylG7kqMhbWktryZ6U0j+DUCrhxLphbhWJG Rk3t27QhUM4IlXtzP0BEgoBntsSwFS/3IKw6uaDUUQjBfQ4hH/lCjRuX12jrndjG7Xo0 +UfCtGpXOSO4AgJ1rGR9a/Smv/NP2aTLYzuUp1bWzHnwV3hTaV/qaArMVdVmxqekd4g7 xfX5Y/0Z30yLbAqKt1glo/cj0/gBwv72A8CJ6MN8YIdukyBlyYbbQFcBqo2VlYJ2s3X/ DtcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781509247; x=1782114047; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=7gTGoROcY88FIx0BKI9qz9m4P1KC5KNO+9LCkMExk6Q=; b=V/qKsLcybJDfNYSeRerUOxn64x5Yv3HEw3njWeY7DaEXKuIOgaJGFeQ6OI0QEt4leq AgVIMr2HMPomauRF+SFILMG7CkxSgli7ko64pfp6z7sAhx5EwnD/ioeKbt5fXu2N93OD E7SmwMvMdNd7xsiIEAjX0wifTJk0aDz2pvKPb4B5G8YjdHvqrXeioBxDnQHvLKtGke9t PNy7dcCQBDJDWgSasTK2bUyHqhjtvNip4gV56kMSgkGBAyHDzXFggJTRZXgq2a4TyeWE Vn2e68Xl58qyD1FInV15xitvaMosjoe4t4rM+qACVjQvUin8YgyWwRUwn6XoJL/IlJa9 oObg== X-Forwarded-Encrypted: i=1; AFNElJ8i7maXIwwNBqBRrySFK/gwmcisKYD2KYw4hgAPyPqx3LobUFcfUfzUgGN9YpL+1MSRxCNtIF6kl8OE4kY=@vger.kernel.org X-Gm-Message-State: AOJu0Yw9bSb56rDQXv/mDoTUDkQCVfYGAtQ61HJsilFjr+13HPK+tLsl cMUljMpDjBuOT46o1ebQqDSK08egSDvG+UpFErOpK2axnMsiBVRYQoFb3UJQ9w== X-Gm-Gg: Acq92OE/SYN3rnvtMAnaDdRf6iGX1r/rgU0QUeOa3bN7ZbZmwIyzzJ4/gEa7NG1F9Lz TOXdyeI4+PQqtgNnvBdxOmYjZR4wIHsVQ4rtp+fsXDnsZjKEfkB+vBlLRTUtGB7ZmO378lFqCqA CAjnPL7sUjc1J3sDxbuzICUMeSNCrVKpU+ao67ZM9lxCWtpPTxCAPteDGNgC0FHuy7l9aTzTYH3 EaHBaSXR1BctcBhtjg2BKM3iQlZCzxTzr1BzS07lruVqaUOEK/Tfd18QszFIjYB8/Wq0CFTroq7 iUWb2TZfHXaBuuhritnE6erOEbJFkLrqSSQrx0yN5/mK68yqHUjoe24kVD35RmnQT/B4JOUEfSW 7LXqZYUSaLhnqpWMSxbJlcFbjpjwKvV019stZig2javihPWyisxrIcAGVOjBB6CX+oN6kz8LttO Z4AgT+KOPWrdze3OfRPSxCOE7PxTyvzow/F7FfjAGQd5eocE4ZcB2fSpCBY3/eTn8xiAwuHmjOs B5WFakVQW5ba819iT3hG/Bsvg== X-Received: by 2002:a17:906:ef0d:b0:bee:d554:f332 with SMTP id a640c23a62f3a-bfe282fb76cmr579858166b.16.1781509247059; Mon, 15 Jun 2026 00:40:47 -0700 (PDT) Received: from ?IPV6:2001:9e8:f12e:9401:c875:96a4:7b6f:72fd? ([2001:9e8:f12e:9401:c875:96a4:7b6f:72fd]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-bfdb4b22544sm413400966b.14.2026.06.15.00.40.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 15 Jun 2026 00:40:46 -0700 (PDT) Message-ID: <9cd444b3-aeb0-46bb-a8a3-1526aa8f191a@gmail.com> Date: Mon, 15 Jun 2026 09:40:45 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] MIPS: smp: report dying CPU to RCU in stop_this_cpu() Content-Language: en-US To: Huacai Chen Cc: Thomas Bogendoerfer , linux-mips@vger.kernel.org, Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , Thomas Gleixner , Jiayuan Chen , linux-rt-devel@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260608093729.12111-1-jelonek.jonas@gmail.com> <731bd6c4-0f70-45a2-8480-8fed315b82b4@gmail.com> From: Jonas Jelonek In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 15.06.26 09:30, Huacai Chen wrote: >> [...] >> >>> However, synchronize_rcu() only gets called in the >>> IS_ENABLED(CONFIG_PREEMPT_RT) case, so I think your configuration >>> needs PREEMPT_RT, right? >>> >>> You said this is the default behavior, but PREEMPT_RT is not enabled by default. >> The condition where this is added has two parts, see [1]. While PREEMPT_RT >> isn't active for MIPS, arch_irq_work_has_interrupt gives false for MIPS (since >> there is no implementation and it falls back to the generic one). This then >> also calls synchronize_rcu. > Sorry, this is my mistake, then what's your preemption model? There > are too many config files for MIPS now. I'm using PREEMPT_NONE, apparently default for all targets in OpenWrt. > Huacai > >>> Huacai >>> >> Best, >> Jonas >> >> [1] https://elixir.bootlin.com/linux/v7.1-rc7/source/kernel/irq_work.c#L291-L302 Best, Jonas