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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3803FC43217 for ; Mon, 7 Mar 2022 08:55:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233181AbiCGI4L (ORCPT ); Mon, 7 Mar 2022 03:56:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233437AbiCGI4K (ORCPT ); Mon, 7 Mar 2022 03:56:10 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9CBC1BEA7; Mon, 7 Mar 2022 00:55:15 -0800 (PST) Date: Mon, 7 Mar 2022 09:55:11 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1646643312; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JoVzBf1uXNcTzGiPbR/fg/8odB0x/Dhp0N0m6GdxpLc=; b=41o4gWkezgvWk2XDLJwhHNQd6xE5gchpopyr67bC28C+0MAqDQU5Q+J/CYaqkDucEHKu5P j7QCHtamiLiAGWTuOIWB3S+i49YXDYtFniewiIr/ydSxb8cBGfotgNF2m3mEOpx73MMcPR GrwVjWiyr/tpjaJpf4fI0Nkx9053gTZBh+1IYrIdN5TkgxCf2FrJ6U5CtWxrZxuOVFfYzw Yhh8LzkHg2j8HrEZVTsbcO7RkYhzyRX1ZvfcASdd87cFpIfp+yN8M9xZ9GzOvDQyWkSabP AemowUH/V58vsQEjl3ulifi/opRG9zcLSumiIrE5MTO6VLAmC2RIA0GJfto9iQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1646643312; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JoVzBf1uXNcTzGiPbR/fg/8odB0x/Dhp0N0m6GdxpLc=; b=md/CxHPZCzL2m9kymyQ2UtneZu8bff63noOjI8mU80fRT5BDsn+PxWkt3keVIigL1h0u9g +JTvhpl/d4aVXRBw== From: Sebastian Andrzej Siewior To: Yunhao Tian Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: PREEMPT_RT causes scheduling errors with f_rndis USB gadget Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 2022-03-06 18:17:54 [+0800], Yunhao Tian wrote: > Hi everyone, Hi, > I'm using Linux 5.15.24-rt31 kernel with PREEMPT_RT enabled, on my > RK3308 board. I set up f_rndis gadget with the following script, and > plugged my board to a x86 Linux computer running 5.15.25 kernel: Is this 5.15.24-rt31 as-is or are there other patches involved? What UDC is used here? =E2=80=A6 > [ 25.993834] NOHZ tick-stop error: Non-RCU local softirq work is > pending, handler #80!!! that is sched =E2=80=A6 > [ 25.995885] NOHZ tick-stop error: Non-RCU local softirq work is > pending, handler #180!!! that is additionally hrtimer. I did touch hrtimer but I did not yet touch sched so I account myself as 50% innocent. You don't have by chance change the thread affinity of tasks/ interrupt threads? The SoC has 4 cores if I see this right. > If I turn off PREEMPT_RT, there won't be any errors while downloading. >=20 > I believe this problem is not tied to any specific board, and anyone > can reproduce this problem using a Raspberry Pi (Although I didn't try > because I don't have one). I would like to ask for assistance > regarding this problem. Let me try dummy_udc=E2=80=A6 Sebastian