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 X-Spam-Level: X-Spam-Status: No, score=-20.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C018AC64E7A for ; Fri, 20 Nov 2020 12:34:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64B9422240 for ; Fri, 20 Nov 2020 12:34:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="YzOEvqBl"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="x7IQaCdE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728235AbgKTMeU (ORCPT ); Fri, 20 Nov 2020 07:34:20 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:40342 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728006AbgKTMeJ (ORCPT ); Fri, 20 Nov 2020 07:34:09 -0500 Date: Fri, 20 Nov 2020 12:34:06 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1605875647; h=from:from:sender:sender:reply-to: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=XtkucJkY/D30mZAY/UaYcw5xhy4fj1HuGP5dHuWrhZA=; b=YzOEvqBll5Jylw1kvTkBVPf3RF+1D+LKX96l13cT5tu4dxusEBaznXtpxl6sxdWtM8P1a9 CsPs4ajLAjCHXrGuipFstSQJzAJMt1Tj71g/QJtPSiQbdPxmNWFavQoPw1c0YFLuXRGWnv iE/tjIv8PgBbCMsIme3Lo0/geEY2ZgLR0zOovK27m7XlQ+TQzaVkFCshgbE2UesU4n9oGE Uq0iIOJrKAVvi1/s9akPvg/YCI4v5l0IyWfno1pyuIwnx3w2yVEdY10C4ZJdoaUix/sJ0q 6pZo3KtSQ7mxGzjiVgIwA2wnAhPluOf7dM6F9RG4/8GpSwfoXN4guv1xwbAVTw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1605875647; h=from:from:sender:sender:reply-to: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=XtkucJkY/D30mZAY/UaYcw5xhy4fj1HuGP5dHuWrhZA=; b=x7IQaCdEhrgJ692Zv5Y0lXQ3sBF0ebKlp4ZHHpLFG8S1oyw38E7e3kthkeSzxRvo/MIxbP 2CKXjCW9ZOGTm3Dw== From: "tip-bot2 for Dietmar Eggemann" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched/uclamp: Allow to reset a task uclamp constraint value Cc: Dietmar Eggemann , "Peter Zijlstra (Intel)" , Yun Hsiang , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20201113113454.25868-1-dietmar.eggemann@arm.com> References: <20201113113454.25868-1-dietmar.eggemann@arm.com> MIME-Version: 1.0 Message-ID: <160587564623.11244.11912480556442620375.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 480a6ca2dc6ed82c783faf7e4a9644769b8397d8 Gitweb: https://git.kernel.org/tip/480a6ca2dc6ed82c783faf7e4a9644769b8397d8 Author: Dietmar Eggemann AuthorDate: Fri, 13 Nov 2020 12:34:54 +01:00 Committer: Peter Zijlstra CommitterDate: Thu, 19 Nov 2020 11:25:47 +01:00 sched/uclamp: Allow to reset a task uclamp constraint value In case the user wants to stop controlling a uclamp constraint value for a task, use the magic value -1 in sched_util_{min,max} with the appropriate sched_flags (SCHED_FLAG_UTIL_CLAMP_{MIN,MAX}) to indicate the reset. The advantage over the 'additional flag' approach (i.e. introducing SCHED_FLAG_UTIL_CLAMP_RESET) is that no additional flag has to be exported via uapi. This avoids the need to document how this new flag has be used in conjunction with the existing uclamp related flags. The following subtle issue is fixed as well. When a uclamp constraint value is set on a !user_defined uclamp_se it is currently first reset and then set. Fix this by AND'ing !user_defined with !SCHED_FLAG_UTIL_CLAMP which stands for the 'sched class change' case. The related condition 'if (uc_se->user_defined)' moved from __setscheduler_uclamp() into uclamp_reset(). Signed-off-by: Dietmar Eggemann Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Yun Hsiang Link: https://lkml.kernel.org/r/20201113113454.25868-1-dietmar.eggemann@arm.com --- include/uapi/linux/sched/types.h | 2 +- kernel/sched/core.c | 70 ++++++++++++++++++++++--------- 2 files changed, 53 insertions(+), 19 deletions(-) diff --git a/include/uapi/linux/sched/types.h b/include/uapi/linux/sched/types.h index c852153..f2c4589 100644 --- a/include/uapi/linux/sched/types.h +++ b/include/uapi/linux/sched/types.h @@ -96,6 +96,8 @@ struct sched_param { * on a CPU with a capacity big enough to fit the specified value. * A task with a max utilization value smaller than 1024 is more likely * scheduled on a CPU with no more capacity than the specified value. + * + * A task utilization boundary can be reset by setting the attribute to -1. */ struct sched_attr { __u32 size; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a9e6d63..e6473ec 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1413,17 +1413,24 @@ done: static int uclamp_validate(struct task_struct *p, const struct sched_attr *attr) { - unsigned int lower_bound = p->uclamp_req[UCLAMP_MIN].value; - unsigned int upper_bound = p->uclamp_req[UCLAMP_MAX].value; + int util_min = p->uclamp_req[UCLAMP_MIN].value; + int util_max = p->uclamp_req[UCLAMP_MAX].value; - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) - lower_bound = attr->sched_util_min; - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) - upper_bound = attr->sched_util_max; + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { + util_min = attr->sched_util_min; - if (lower_bound > upper_bound) - return -EINVAL; - if (upper_bound > SCHED_CAPACITY_SCALE) + if (util_min + 1 > SCHED_CAPACITY_SCALE + 1) + return -EINVAL; + } + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { + util_max = attr->sched_util_max; + + if (util_max + 1 > SCHED_CAPACITY_SCALE + 1) + return -EINVAL; + } + + if (util_min != -1 && util_max != -1 && util_min > util_max) return -EINVAL; /* @@ -1438,20 +1445,41 @@ static int uclamp_validate(struct task_struct *p, return 0; } +static bool uclamp_reset(const struct sched_attr *attr, + enum uclamp_id clamp_id, + struct uclamp_se *uc_se) +{ + /* Reset on sched class change for a non user-defined clamp value. */ + if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP)) && + !uc_se->user_defined) + return true; + + /* Reset on sched_util_{min,max} == -1. */ + if (clamp_id == UCLAMP_MIN && + attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN && + attr->sched_util_min == -1) { + return true; + } + + if (clamp_id == UCLAMP_MAX && + attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX && + attr->sched_util_max == -1) { + return true; + } + + return false; +} + static void __setscheduler_uclamp(struct task_struct *p, const struct sched_attr *attr) { enum uclamp_id clamp_id; - /* - * On scheduling class change, reset to default clamps for tasks - * without a task-specific value. - */ for_each_clamp_id(clamp_id) { struct uclamp_se *uc_se = &p->uclamp_req[clamp_id]; + unsigned int value; - /* Keep using defined clamps across class changes */ - if (uc_se->user_defined) + if (!uclamp_reset(attr, clamp_id, uc_se)) continue; /* @@ -1459,21 +1487,25 @@ static void __setscheduler_uclamp(struct task_struct *p, * at runtime. */ if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) - __uclamp_update_util_min_rt_default(p); + value = sysctl_sched_uclamp_util_min_rt_default; else - uclamp_se_set(uc_se, uclamp_none(clamp_id), false); + value = uclamp_none(clamp_id); + + uclamp_se_set(uc_se, value, false); } if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP))) return; - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN && + attr->sched_util_min != -1) { uclamp_se_set(&p->uclamp_req[UCLAMP_MIN], attr->sched_util_min, true); } - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX && + attr->sched_util_max != -1) { uclamp_se_set(&p->uclamp_req[UCLAMP_MAX], attr->sched_util_max, true); }