From nobody Thu Dec 18 23:00:18 2025 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 C60C119E992 for ; Thu, 6 Mar 2025 05:31:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741239075; cv=none; b=VN2XsbUepHaNCNkjexj41oZn6fVMxxX8rPIxdmxd/wip3jAkWwWxvNSq9hgKJNVyMAU/zVfmuYtvJqKeEFSMCbp3k0I8fWbSBcH+nu89l7XGW0pUdAY5Ap0BhWbZ4qalOvUE0fB4vnz68JY3wq4y+1TRraHNe4NZ8lzE4Ev8/J4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741239075; c=relaxed/simple; bh=Ux6XPkiSd9LmsIFG4lAikiWwTmewyPORLgKMMIU8+kk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QZCOhVI3XdpLFChvVsrvbsMKXfTZDRn30Ai4sKaNhyoUT80lnw/fFNRICMjhNss6s85/tNX4PzWPdXJmKV8JrYBXKEKqN49tIdXE4U5ywdd6xz1bz81EoCNt0KDU2v13EjHqAIiE3z2klsKsVogPJZBqW9gWWJeIE6R1HwDEokA= 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=P/wKzUG/; arc=none smtp.client-ip=148.163.158.5 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="P/wKzUG/" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 525Kct2O028614; Thu, 6 Mar 2025 05:30:19 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=dSxuRWzlY0rKG+DCw odJHCr5eVahssaJaGkjKtrf8Dw=; b=P/wKzUG/NxlKQD4tlL70c81RDajVF4f6Y XsZ0rUH2vOpMaCrBfs41NsqSrMVi5jMcgos0c7eCB3yDQUEwZQOzwx2NTeNKKmJf LG80hRj0SgyOy4efaHoTRK9ClBGsdtewqIRTOxQJpuPXWmOY1EGn9tvZm6vP6G3p 4ashdrwlDx3/BkFgRnzeEpdj4QALqSuGH8Mqv3IbxtWkUvu43nAYVwdk/atB75TB OiVNMyimcKAvgmKN6426Zs1qRpIpXEcUmR6Gkv4IFhg4P3ObKSaRFIn0Kt2+Yl9K ttQwMrwGQL24FMWAV8yD3FXsJ/ITMRxO+oqB1neBeCwSmJEJTqQjQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 456wu01uxb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Mar 2025 05:30:19 +0000 (GMT) Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.18.0.8/8.18.0.8) with ESMTP id 5265UIfj004827; Thu, 6 Mar 2025 05:30:18 GMT Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 456wu01ux7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Mar 2025 05:30:18 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 5264jnnv009015; Thu, 6 Mar 2025 05:30:18 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 454cxyq2b6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Mar 2025 05:30:17 +0000 Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 5265UE3Q56230224 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 6 Mar 2025 05:30:14 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4D26C20049; Thu, 6 Mar 2025 05:30:14 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0722720040; Thu, 6 Mar 2025 05:30:12 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.in.ibm.com (unknown [9.109.215.252]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 6 Mar 2025 05:30:11 +0000 (GMT) From: Shrikanth Hegde To: juri.lelli@redhat.com, linux-kernel@vger.kernel.org Cc: sshegde@linux.ibm.com, mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, hbathini@linux.ibm.com, joelagnelf@nvidia.com Subject: [PATCH 1/2] sched/deadline: use online cpus for validating runtime Date: Thu, 6 Mar 2025 10:59:53 +0530 Message-ID: <20250306052954.452005-2-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20250306052954.452005-1-sshegde@linux.ibm.com> References: <20250306052954.452005-1-sshegde@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: QVAUM5Op6aG5qmHiysJsO5E0-zkDT0Nz X-Proofpoint-ORIG-GUID: CiGkXSAqmODroZBFBmVJh_wJKW0iZrdk X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1093,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-03-06_02,2025-03-05_02,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=0 suspectscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 bulkscore=0 adultscore=0 spamscore=0 mlxlogscore=999 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2502100000 definitions=main-2503060034 Content-Type: text/plain; charset="utf-8" ftrace selftest reported failure since writing -1 to sched_rt_runtime_us return -EBUSY. This happens when the possible CPUs is different than the active CPUS. Active CPUs are part of one root domain, while remaining CPUs are part of def_root_domain. Since active cpumask is being used, this results in cpus=3D0 when a non active CPUs is used in the loop. Fix it by looping over the online CPUs instead for validation the bandwidth calculations. Signed-off-by: Shrikanth Hegde Acked-by: Juri Lelli --- kernel/sched/deadline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 2d0f571f95e9..7ea9c040c72f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -3187,7 +3187,7 @@ int sched_dl_global_validate(void) * value smaller than the currently allocated bandwidth in * any of the root_domains. */ - for_each_possible_cpu(cpu) { + for_each_online_cpu(cpu) { rcu_read_lock_sched(); =20 if (dl_bw_visited(cpu, gen)) --=20 2.39.3 From nobody Thu Dec 18 23:00:18 2025 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 3431619E98D for ; Thu, 6 Mar 2025 05:30:44 +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=1741239046; cv=none; b=cl9hyo+3k77JLvt0QW81pbohVYSGtbtO2ItFMPTPmIo06d3EMssROFeCNKUBYSzp7bP3DZdH72NCkV3Ce4NYhFwmJwz/H4KKHMm/J/z1deEZWo8CgH7pEgPF5VKRj299gpriKhJgNyCIVBJWXM709rFX6PT/CkyimEVQiRL25ws= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741239046; c=relaxed/simple; bh=V+qZrTq3XKqDR+h+jX0jXtqdThW85XNK/pxkTOR434Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LJvnY5f4g+JNW4VpaqPwJaOMRavaWCx5OPyhN9t9VAw0NsevVoQmliEi8UaaJS4dfuuF11c/PzeMPQSDNmTakYH7UKH0f2i0HY2192NXoGIypbS6px6Lai1YhhmVCKhw00k1xRqnQ78+skRAd3HhQysCMiyAFrSbxI8owsrJojI= 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=Sk2zuA3d; 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="Sk2zuA3d" 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 525MNhEk000401; Thu, 6 Mar 2025 05:30:24 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=diTIjZ+5K2ZYnlDKE Z5q9v0N3zMw6ZPLbDxVEAmlZWI=; b=Sk2zuA3dn0GZcChpr1c9/npM2UPJhkU8u nSVe+0GMdPC8J30MrpVKMRc2pGjimbv0oa5OdmGrbS1On77CULA9URgc4rMamnvd 7ewzS+ajq6Zxdvz26f7i9sg4JpXAjFqc9WcVpO0z4FiAVowUP4Qm1reslTp4VJxZ Xz6tS8WurxCgBYe5o20zL3BlJ2dcp7nfnlLkuic9nB9eMj7XGY3BlsKD6nrSfy8p Ek/NWbgVVVwoLCdTzCWX/xTSeB8AYzkecKbYGk+/WO78vV7KrLlYARpr4KrT7SMC 54JhFQ9qQmLEqSll5/uMfz1Ri/+STTVcofedtGWWnNF1tSgPIO9lA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 456pnavcjr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Mar 2025 05:30:23 +0000 (GMT) Received: from m0353729.ppops.net (m0353729.ppops.net [127.0.0.1]) by pps.reinject (8.18.0.8/8.18.0.8) with ESMTP id 5265NN0B022526; Thu, 6 Mar 2025 05:30:23 GMT Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 456pnavcjk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Mar 2025 05:30:23 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 5265Ce4q020845; Thu, 6 Mar 2025 05:30:22 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 454djnpxhr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Mar 2025 05:30:21 +0000 Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 5265UHUo50594236 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 6 Mar 2025 05:30:17 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B073020049; Thu, 6 Mar 2025 05:30:17 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7312B20040; Thu, 6 Mar 2025 05:30:15 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.in.ibm.com (unknown [9.109.215.252]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 6 Mar 2025 05:30:15 +0000 (GMT) From: Shrikanth Hegde To: juri.lelli@redhat.com, linux-kernel@vger.kernel.org Cc: sshegde@linux.ibm.com, mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, hbathini@linux.ibm.com, joelagnelf@nvidia.com Subject: [PATCH 2/2] sched/rt: update limit of sched_rt sysctl in documentation Date: Thu, 6 Mar 2025 10:59:54 +0530 Message-ID: <20250306052954.452005-3-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20250306052954.452005-1-sshegde@linux.ibm.com> References: <20250306052954.452005-1-sshegde@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: R_dZG9f8LwN3Z9LG-d8ZrJZmQ8Clbmav X-Proofpoint-GUID: -no_t_MgLe0aMN-TiBa5_o_yNG9T442l X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1093,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-03-06_02,2025-03-05_02,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1011 malwarescore=0 phishscore=0 spamscore=0 adultscore=0 lowpriorityscore=0 mlxlogscore=867 bulkscore=0 impostorscore=0 priorityscore=1501 suspectscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2502100000 definitions=main-2503060038 Content-Type: text/plain; charset="utf-8" By default fair_server dl_server allocates 5% of the bandwidth to the root domain. Due to this writing any value less than 5% fails due to -EBUSY. cat /proc/sys/kernel/sched_rt_period_us 1000000 $ echo 49999 > /proc/sys/kernel/sched_rt_runtime_us -bash: echo: write error: Device or resource busy $ echo 50000 > /proc/sys/kernel/sched_rt_runtime_us $ Since the sched_rt_runtime_us allows -1 as the minimum, put this restriction in the documentation. One should check average of runtime/period in=20 /sys/kernel/debug/sched/fair_server/cpuX/* for exact value. Signed-off-by: Shrikanth Hegde Reviewed-by: Juri Lelli --- Documentation/scheduler/sched-rt-group.rst | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/scheduler/sched-rt-group.rst b/Documentation/sch= eduler/sched-rt-group.rst index 80b05a3009ea..ab464335d320 100644 --- a/Documentation/scheduler/sched-rt-group.rst +++ b/Documentation/scheduler/sched-rt-group.rst @@ -102,6 +102,9 @@ The system wide settings are configured under the /proc= virtual file system: * sched_rt_period_us takes values from 1 to INT_MAX. * sched_rt_runtime_us takes values from -1 to sched_rt_period_us. * A run time of -1 specifies runtime =3D=3D period, ie. no limit. + * sched_rt_runtime_us/sched_rt_period_us > 0.05 inorder to preserve + bandwidth for fair dl_server. For accurate value check average of + runtime/period in /sys/kernel/debug/sched/fair_server/cpuX/ =20 =20 2.2 Default behaviour --=20 2.39.3