From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 E843179FE; Wed, 8 Jan 2025 04:56:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736312217; cv=none; b=q9Ae8rfBD8pOrzPr6m6Yu2WRpjD3EXxnZlBFHTabgih4USPcMvoevDwi0VdsGtPQ3eKX++FQeewvTyNOG33v8jsIRIVM1hBwSz750zyqq2pI4qzdDNvfimAOPkGioav59Elo9XoHtgIREm81tPlJFayzuDRT7wyQeXB3Zo8jOFo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736312217; c=relaxed/simple; bh=2w/rNo0EdC6MPXNXtBSlyh+3s3vZO2+7r06jX7Nw3dU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kePwvY5La1Rhh4gpDv7Hx1yWll3RMvJWXYAPbc8Jrskm7F7o6exHlqkiUJMhDIs7DQZkssBuNJcgz2f8uSckYMGNO9dI89Tsf+I7VOphELC5pi+FG6eGZhxtj2H/rCG9j1DM+/UA2dnJlXcBB2WDbn85CRNJyPXDFVl0Nk5SPjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=o6loSkfe; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="o6loSkfe" Received: from pps.filterd (m0353729.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 507Nx5cj024746; Wed, 8 Jan 2025 04:56:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=yl7WOU HBv0UNTaIo+rq/jnbruTQsoczPnl2Vyg7Z2Lk=; b=o6loSkfeRvMhzRjd9ll9Yf vk54YpZ0qFH2XFELxdvjHcnm0XPRdPryGAf+6HbTSYLFWb2Aqzy92cywLDBnBggF 2y5d18ODBPy0baiz/PKQQEh+Vf3LBpMsimzgHTsI9vnnEsPYuMr0aNg4a8DS7UKF 7jCuuE2g7BSo9UslQ1U+XUDaeBp7is15ugVVJygIHnzmJWV8ZcmOSLmAHs0hpIte mCXimjqvvGSsd/KoRIanVkSsx+NHC3SxMQ8k2JC5PLHXjWJ3Tz/6QpmGrotNGJoF cZSl5KY2Y/i58lgE1dSaEtwgfTI0lO/n2Rh1vD/4oe6BGGD0n74GWS5FhfLSI74Q == Received: from ppma11.dal12v.mail.ibm.com (db.9e.1632.ip4.static.sl-reverse.com [50.22.158.219]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 441edj0wa6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Jan 2025 04:56:41 +0000 (GMT) Received: from pps.filterd (ppma11.dal12v.mail.ibm.com [127.0.0.1]) by ppma11.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 5082NTQ5026179; Wed, 8 Jan 2025 04:56:41 GMT Received: from smtprelay07.fra02v.mail.ibm.com ([9.218.2.229]) by ppma11.dal12v.mail.ibm.com (PPS) with ESMTPS id 43yj125qe3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Jan 2025 04:56:40 +0000 Received: from smtpav04.fra02v.mail.ibm.com (smtpav04.fra02v.mail.ibm.com [10.20.54.103]) by smtprelay07.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 5084udDu62456140 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 Jan 2025 04:56:39 GMT Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 575C920043; Wed, 8 Jan 2025 04:56:39 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EDD4320040; Wed, 8 Jan 2025 04:56:37 +0000 (GMT) Received: from [9.39.20.66] (unknown [9.39.20.66]) by smtpav04.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 8 Jan 2025 04:56:37 +0000 (GMT) Message-ID: Date: Wed, 8 Jan 2025 10:26:36 +0530 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] powerpc: Allow scheduling of IRQ with PREEMPT_RT To: Robert Joslyn Cc: "linux-kernel@vger.kernel.org" , "linux-rt-users@vger.kernel.org" , "tglx@linutronix.de" , "rostedt@goodmis.org" , Sebastian Andrzej Siewior References: <20241226191238.2559880-1-robert_joslyn@selinc.com> <20250107115606.q67--i0f@linutronix.de> From: Shrikanth Hegde Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: Vn5aBguMhkirMZeKmLiNSvu1ylBlAjje X-Proofpoint-ORIG-GUID: Vn5aBguMhkirMZeKmLiNSvu1ylBlAjje X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 mlxscore=0 lowpriorityscore=0 bulkscore=0 mlxlogscore=450 phishscore=0 malwarescore=0 impostorscore=0 priorityscore=1501 clxscore=1015 adultscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2411120000 definitions=main-2501080033 On 1/7/25 23:43, Robert Joslyn wrote: >> -----Original Message----- >> From: Shrikanth Hegde >> Sent: Tuesday, January 7, 2025 5:10 AM >> To: Robert Joslyn >> Cc: linux-kernel@vger.kernel.org; linux-rt-users@vger.kernel.org; >> tglx@linutronix.de; rostedt@goodmis.org; Sebastian Andrzej Siewior >> >> Subject: Re: [PATCH] powerpc: Allow scheduling of IRQ with PREEMPT_RT >> >> [Caution - External] >> >> On 1/7/25 17:26, Sebastian Andrzej Siewior wrote: >>> On 2024-12-26 11:12:38 [-0800], Robert Joslyn wrote: >>>> This branch is needed to allow preemptible IRQs to be scheduled, >>>> otherwise the kernel hangs during boot on my e300 based platforms. >>>> This branch is needed for both CONFIG_PREEMPT and >> CONFIG_PREEMPT_RT, >> >> Hi Robert. >> >> Are you running with preempt=full or enabled preempt_rt ? >> rt is yet to be supported on powerpc. are you having it enabled out of tree? > > I'm running PREEMPT_RT using the out of tree patches on 6.6.58-rt45: > https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git/ > > I haven't tried using the mainline kernel, since as you said, it doesn't have powerpc support for PREEMPT_RT yet. > >> >> Also, I have sent out patch to enable dynamic preemption. It uses >> preempt_model_preemptible. >> I think it should work for you as well. If you could give that a try and ensure it >> works, it would be great. >> https://urldefense.com/v3/__https://lore.kernel.org/all/20250106051919.5 >> 5020-2- >> sshegde@linux.ibm.com/__;!!O7uE89YCNVw!IDeomstGeuiEZi9FmLHH8C2xo >> PPo_ewL- >> k2kiQ9CmVID35U4J_v3Dkafjo3RnS9ygPoUZWwyyp91SP2euRkKArk$ > > Does the dynamic preemption support let me enable the same functionality as PREEMPT_RT with the out of tree patches? I can test it out either way. > with preempt_rt, dynamic preemption allows you to switch between full and lazy. without preempt_rt, you can switch between none, voluntary,full and lazy. > Thanks, > Robert