From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3B264C982D2 for ; Fri, 18 Sep 2026 01:22:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:Cc:From:References:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Kr9XR1CvnQWLyEr1dZjA2EdfuQi+TOXBVnkraFi7+d0=; b=3LTzQz4WFLPZred6CQiCqMERBt ch8JG0a+9sejA6Q49dBxMdwcpbZw3b63yDcIopv9GJE8qCM6GU49EtIwQtLLoOfxjqj/8C0ZqZENm XmrJRCr4Nx20oGCg7af3r60DCF39uAg2yaiz5ukS4c0jlfbU80Y/h4ZuP1TA8sKxlKbrk7A0dFb1C FGt0s8RrXfE0eEKJ6FHf9HGUWOfq6MiSUvneciI7LuTMhY16npC+QPc20/4iN7B0HfX7cJ9JytEUp i1l/ezixyS8XUy8eLzKVyxNGEn/ehp/9HSD1Ye+LwEtDrgFN7EG7wYjJLEg9hrSufQV9t1oZ8/i+0 levVxinQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7NJ0-0000000D8hN-17El; Fri, 18 Sep 2026 01:22:22 +0000 Received: from mail-m1602365261.xmail.ntesmail.com ([160.236.52.61]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7NIx-0000000D8dx-0b1O for linux-arm-kernel@lists.infradead.org; Fri, 18 Sep 2026 01:22:21 +0000 Received: from [127.0.0.1] (unknown [61.154.14.86]) by smtp.qiye.163.com (Hmail) with ESMTP id 4e34b9923; Fri, 18 Sep 2026 09:22:05 +0800 (GMT+08:00) Message-ID: <11cdc24a-962a-4f44-b91c-445c2ac80c02@rock-chips.com> Date: Fri, 18 Sep 2026 09:21:48 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [BUG?] Possible scheduler bug on Rock 5B RK3588 on 7.2.5 To: No SPAM here References: Content-Language: en-US From: Chaoyi Chen Cc: Peter Zijlstra , linux-arm-kernel@lists.infradead.org In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-HM-Tid: 0aa0b21b3f3603a7kunm35fe1041e5f2a7 X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkZTR9KVklJGBpITU8aGB0dH1YVFA kWGhdVEwETFhoSFyQUDg9ZV1kYEgtZQVlNSlVKTk9VSk9VQ01ZV1kWGg8SFR0UWUFZT0tIVUJCSU 5LVUpLS1VKQktCWQY+ DKIM-Signature: a=rsa-sha256; b=UhtFZuOwM0OJ1b2kxJxm7PAqOq0tQqJBE3+mA7cIWzyIYHG1ztkAzBwtR6UCDNhev6HXkKveXq6GBvJfkFHBsts2jOVIvOGCdoxv7lXcONtWegGct6Yv2BygtlbWU7MNSzJH03q+3vHn5XJ04VV0vEUfC/vpcNnHypJ5gi5Z6G0=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=Kr9XR1CvnQWLyEr1dZjA2EdfuQi+TOXBVnkraFi7+d0=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260917_182219_751382_62947FD3 X-CRM114-Status: GOOD ( 11.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 9/18/2026 3:15 AM, No SPAM here wrote: > Hi > > On Thursday, 17 September 2026 at 03:37, Chaoyi Chen wrote: > >> Hello Trevor, >> >> On 9/17/2026 9:21 AM, No SPAM here wrote: >>>> Would you mind trying to disable `CONFIG_SCHED_CLUSTER` and checking whether >>>> the problem still reproduces? > > trevor@rock-5b:~$ uname -a > Linux rock-5b 6.18.52-current-rockchip64 #1 SMP PREEMPT Mon Sep 14 11:36:19 UTC 2026 aarch64 GNU/Linux > trevor@rock-5b:~$ grep CONFIG_SCHED_CLU /boot/config-6.18.52-current-rockchip64 > # CONFIG_SCHED_CLUSTER is not set > trevor@rock-5b:~$ sar | tail -5 > > 18:50:15 CPU %user %nice %system %iowait %steal %idle > 19:00:15 all 99.89 0.00 0.11 0.00 0.00 0.00 > 19:10:15 all 99.89 0.00 0.11 0.00 0.00 0.00 > Average: all 99.89 0.00 0.11 0.00 0.00 0.00 > > Been running stress --cpu 8 since 18:47 and so far it is using all 8 cores at 100%. It would normally have shown the 7/8ths problem after 20s or so, maybe 2 or 3 minutes at max. So I'd say this setting is definitely involved. > Thank you very much for testing. I'm not a scheduler expert, but I see that CONFIG_SCHED_CLUSTER is enabled by default on arm64 [0]. Peter is the maintainer and author of this series. @Peter, do you have any further insights? Thank you! This thread background is here[1]. [0]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7bd291abe2da09f59dca81f35a4ec220e5e138a2 [1]: https://lore.kernel.org/all/f15f8166-c1e4-45dc-9ddd-4ec887e415eb@gdead.co.uk/ -- Best, Chaoyi