From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-57-252.mail.qq.com (out162-62-57-252.mail.qq.com [162.62.57.252]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F0DE91D935C; Mon, 6 Jan 2025 10:00:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.57.252 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736157607; cv=none; b=XoyKVllFICVzhz9avzGOzSlJQWLrkEDUadEXZVQLon6hyNW3Ga3rqRTHsZwzLjBYrApAKkevNRMlvGPbONof/ZpU1gQ9p+te3qhXM1wc2FzkVD9xlIgw5dhHqADy4LOUozMOU0adqS6PfeDz1rbjcJAA0i2ziaHbs2hxKnDjspM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736157607; c=relaxed/simple; bh=odrdTO5O0rEniTcE1eV7WzfcuDhinmrYoT91areJi24=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=G+TY7q8RRrroKSRzGV1zhje/7svM717+9yYgmnZcHv1GWPYzBUqilRGtD5tTwYxkivFJy5Yr2VKRMtMBC0iWg0pWxWBHypY3FjuA7FbuyZr35coGBVykDmsUf42DkZx2JyRG9h1VYphl4GY8z8upN/deXG67g6Rbp/zdXU5Hnds= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=H6G+hVW6; arc=none smtp.client-ip=162.62.57.252 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="H6G+hVW6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1736157292; bh=No06V+8q8JBfJr+GfYmrVNeP1TRqGKgHXiwOwFF1FP0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=H6G+hVW6l4Bs+LhwEJJJ355nA223im7jvAK1VfOrRRg/UrGOE+VfzNyTnEegYbH90 6Mz3I1wEAv3R8fu4cAdscyEyrJxOZxe5hNzG1BjOgtc4S+s7AbkR0woZ4pX8zp2yqZ dZ9y2hLyDPUpRuCtoM6LbIKkX1tCjf1VCAaTY0vI= Received: from localhost.localdomain ([101.227.46.164]) by newxmesmtplogicsvrszc25-0.qq.com (NewEsmtp) with SMTP id C2902420; Mon, 06 Jan 2025 17:48:41 +0800 X-QQ-mid: xmsmtpt1736156921tcpukmmgq Message-ID: X-QQ-XMAILINFO: NnA3IMNPwBd+w/Yg1uKuc/Ew4ioUNz+bURqbe8urInqzl+oq1pi4fpDds/i+Y8 /1PlJPF+nhxfkeoXv6giLUYUjkvULTCI0qRxw1IKU+ESV7REOj41O1LVVxcrzsS3CxXu115+nYWl ONFmsnQu2Fd0wJaBxVXzI5Rsc+tXIhVQSvBJezjnwTZb5ie+LbO05GIl5Y0b325VhkOJS8xfbCwL dJus1EQwaszpBzqgTHYjbkT7hh4BUvgE44gobqLa+ImEpwtA6uNwWDBplkU9+g4lIkHqPqCLxIKt 8GAGtdWfWIH9V3wQPHx/HfZuFJE4WRWeiRdXUp8bxgfUmR5SM1iZKFw+9JTg8Or1UvcP3835LwjC oVJgx69BFFx3ny+3ZMae5cH9+BdMURJEaOCSMkiZakHKztMLKgi7YHxtuFJI9EEZ8Z3S4VuVuOJK OMDyoeAcseCf8rDujwd2LILSzDmykqzdo+qkAgvoPpPZX1FMx/7TvUoHUdpmaN8rxFz6Lsl43TNx Y1MGjTPNEoGjbqo84WLsxlKcep8naUBlALo6pi4g86pBVBSpcRHEVI+zEJJpWiv8P1eldiCBohKW NvH0Rx0Kvce8twWL0ubtKzFodL3T5Y01I6HsoW5WusskIGCiDV3FR3YqL8BII1e1uGnGANLAPEYl kAdV9KK3xYlPmNbnVkhOWhx9mArvndeAx/2ErZBNv4ZGUN4JZiVo/ktY7Z8w9sCtm2rPYzm79/6b /aOzbUszkpS653kAO7cqfdKh6LUQCLHz1IzkI1yep+q+sHh//9ZfLz4dHEitQQwGzcNIg2UKCAmR AFPWWiP3NG6Dt4s/iTzj5QdgQb/5Ulru+04LEJpg5IisYXMfY/W1aSXJA6hxMK1grqKVp7v7+3nt 9cNUH+w7ZeURz2bd9beUI3EfpQD8hhEdlnznGQ1V67Ud/n1IFnws5fuKpi+jntO3ZSbvyDK/9/38 /R1/OtdylHioG3tqU8Rn7sA557aJKmqOClf8EBjAv0GWr9DlavQyrwwbP7QfT4d38Me6krlu0EDv DZWC1jZDwPRcJlqXX03xGAGX0cS6wcKq3Zzq3T1g== X-QQ-XMRINFO: OWPUhxQsoeAVDbp3OJHYyFg= From: wujing To: peterz@infradead.org Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, mingo@redhat.com, realwujing@qq.com, sasha.levin@linux.microsoft.com, stable@vger.kernel.org, yuanql9@chinatelecom.cn Subject: Re: [PATCH] sched/fair: Fix ksmd and kthreadd running on isolated CPU0 on arm64 systems Date: Mon, 6 Jan 2025 17:48:40 +0800 X-OQ-MSGID: <20250106094840.123528-1-realwujing@qq.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250106092134.GA20870@noisy.programming.kicks-ass.net> References: <20250106092134.GA20870@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The reason this issue does not occur on x86 architecture is that x86 does not use the `select_idle_cpu` function for core selection. Instead, it uses the `select_idle_smt` function. However, there is still an issue on x86 where isolated cores are not properly excluded. My other commit, `sched/fair: Correct CPU selection from isolated domain`, addresses the issue of isolated cores on x86. > Your subject explicitly mentions arm64, however there is absolutely > nothing arm64 specific to this patch, as such the subject is just plain > wrong.