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 08C4EC433F5 for ; Thu, 12 May 2022 16:36:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356549AbiELQgh (ORCPT ); Thu, 12 May 2022 12:36:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356530AbiELQf6 (ORCPT ); Thu, 12 May 2022 12:35:58 -0400 Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7EDA1275E7 for ; Thu, 12 May 2022 09:35:57 -0700 (PDT) Received: by mail-wr1-x436.google.com with SMTP id b19so8005037wrh.11 for ; Thu, 12 May 2022 09:35:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=5LSQF4qQ6PdU2l44s8zh7kHvz3U3R9H2i+FKozzkMrk=; b=zn+g1Ycy1XsWOwIRH1IZWmSxoblP7fkC3C+xhRAAZcnQbWJZArprv6QGJwokYaEgI4 OFjd7l6KuNlcrbz4HNoEWaxKazwlFu6rBI1ebSgc79IBRrEPn1mYEi2rHVgWQeedm4TZ 89ZCh10ifROHuV/qmJqL1UU4iNigCCVLKvCokb52aSoR/lnP38dl+uDne0gpVVUwRWZs gOQJAtUoNAIXFKzAiqEhq6dMXV05Il441S/tO5l4BLMjcj1hmuXlon0+1o3+l/0So3+W IUymuBo/d88SX3cij56hjplOgvcLDgmo1t0MrbF4fVZ7p/NgIYq03yr9em8VQIVcGy19 jdgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=5LSQF4qQ6PdU2l44s8zh7kHvz3U3R9H2i+FKozzkMrk=; b=unkwltldTY174tcwb6jn5+a2Yd79UiTz7TPw16hu/CxqNDgZO4MsZR2kiKvT+4mzAZ 4rZkskXKJZo9sFncslOSoFZWwtNPLgWzxgSgnIgA+nakSeTXMKLM9aCFB+oH6GrQtBKJ tAOEBRW0WOsoteM368D1F7aW0j/asBSfPOgSwNFba67EhKqiFhQ5NwYGpwrv91SIuTWg JqpJnwm99asc/DKxv6k+fQa5iAWdDuTecelRWpEiNf+Xbm2ztNwaldbEssaLEDbuqzRk HINNJR9wKHJJc5hyzy5EAyfxvrK3du2hW2vr/kzFjrWkkqWalLcUhD/bw4f3Nos26gms irGw== X-Gm-Message-State: AOAM533cDSqEXvF0QcDakI+FzcnxNBnceXdQk4H2m2qOxLEez9lHD1V9 VSo2coxci9kaoURu8SGAu4VqlQ== X-Google-Smtp-Source: ABdhPJz42eGyH0dwTt5/MYB8DtEJQeazcoRnR88OzcJR1YmQeSqxE12GDN8WDCVz/BkRBaZMW0HxLQ== X-Received: by 2002:a5d:6504:0:b0:20c:e8c7:55f7 with SMTP id x4-20020a5d6504000000b0020ce8c755f7mr448731wru.276.1652373355603; Thu, 12 May 2022 09:35:55 -0700 (PDT) Received: from localhost.localdomain ([2a01:e0a:f:6020:253e:ae0a:544b:2cb1]) by smtp.gmail.com with ESMTPSA id j25-20020adfa799000000b0020c5253d8dbsm21814wrc.39.2022.05.12.09.35.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 May 2022 09:35:54 -0700 (PDT) From: Vincent Guittot To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, parth@linux.ibm.com Cc: qais.yousef@arm.com, chris.hyser@oracle.com, valentin.schneider@arm.com, patrick.bellasi@matbug.net, David.Laight@aculab.com, pjt@google.com, pavel@ucw.cz, tj@kernel.org, qperret@google.com, tim.c.chen@linux.intel.com, joshdon@google.com, Vincent Guittot Subject: [PATCH v2 3/7] sched: Allow sched_{get,set}attr to change latency_nice of the task Date: Thu, 12 May 2022 18:35:30 +0200 Message-Id: <20220512163534.2572-4-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220512163534.2572-1-vincent.guittot@linaro.org> References: <20220512163534.2572-1-vincent.guittot@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Parth Shah Introduce the latency_nice attribute to sched_attr and provide a mechanism to change the value with the use of sched_setattr/sched_getattr syscall. Also add new flag "SCHED_FLAG_LATENCY_NICE" to hint the change in latency_nice of the task on every sched_setattr syscall. Signed-off-by: Parth Shah [rebase and add a dedicated __setscheduler_latency ] Signed-off-by: Vincent Guittot --- include/uapi/linux/sched.h | 4 +++- include/uapi/linux/sched/types.h | 19 +++++++++++++++++++ kernel/sched/core.c | 25 +++++++++++++++++++++++++ tools/include/uapi/linux/sched.h | 4 +++- 4 files changed, 50 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h index 3bac0a8ceab2..b2e932c25be6 100644 --- a/include/uapi/linux/sched.h +++ b/include/uapi/linux/sched.h @@ -132,6 +132,7 @@ struct clone_args { #define SCHED_FLAG_KEEP_PARAMS 0x10 #define SCHED_FLAG_UTIL_CLAMP_MIN 0x20 #define SCHED_FLAG_UTIL_CLAMP_MAX 0x40 +#define SCHED_FLAG_LATENCY_NICE 0x80 #define SCHED_FLAG_KEEP_ALL (SCHED_FLAG_KEEP_POLICY | \ SCHED_FLAG_KEEP_PARAMS) @@ -143,6 +144,7 @@ struct clone_args { SCHED_FLAG_RECLAIM | \ SCHED_FLAG_DL_OVERRUN | \ SCHED_FLAG_KEEP_ALL | \ - SCHED_FLAG_UTIL_CLAMP) + SCHED_FLAG_UTIL_CLAMP | \ + SCHED_FLAG_LATENCY_NICE) #endif /* _UAPI_LINUX_SCHED_H */ diff --git a/include/uapi/linux/sched/types.h b/include/uapi/linux/sched/types.h index f2c4589d4dbf..db1e8199e8c8 100644 --- a/include/uapi/linux/sched/types.h +++ b/include/uapi/linux/sched/types.h @@ -10,6 +10,7 @@ struct sched_param { #define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */ #define SCHED_ATTR_SIZE_VER1 56 /* add: util_{min,max} */ +#define SCHED_ATTR_SIZE_VER2 60 /* add: latency_nice */ /* * Extended scheduling parameters data structure. @@ -98,6 +99,22 @@ struct sched_param { * 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. + * + * Latency Tolerance Attributes + * =========================== + * + * A subset of sched_attr attributes allows to specify the relative latency + * requirements of a task with respect to the other tasks running/queued in the + * system. + * + * @ sched_latency_nice task's latency_nice value + * + * The latency_nice of a task can have any value in a range of + * [MIN_LATENCY_NICE..MAX_LATENCY_NICE]. + * + * A task with latency_nice with the value of LATENCY_NICE_MIN can be + * taken for a task requiring a lower latency as opposed to the task with + * higher latency_nice. */ struct sched_attr { __u32 size; @@ -120,6 +137,8 @@ struct sched_attr { __u32 sched_util_min; __u32 sched_util_max; + /* latency requirement hints */ + __s32 sched_latency_nice; }; #endif /* _UAPI_LINUX_SCHED_TYPES_H */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 1f04b815b588..036bd9ff66e9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7200,6 +7200,15 @@ static void __setscheduler_params(struct task_struct *p, p->rt_priority = attr->sched_priority; p->normal_prio = normal_prio(p); set_load_weight(p, true); + +} + +static void __setscheduler_latency(struct task_struct *p, + const struct sched_attr *attr) +{ + if (attr->sched_flags & SCHED_FLAG_LATENCY_NICE) { + p->latency_nice = attr->sched_latency_nice; + } } /* @@ -7326,6 +7335,13 @@ static int __sched_setscheduler(struct task_struct *p, return retval; } + if (attr->sched_flags & SCHED_FLAG_LATENCY_NICE) { + if (attr->sched_latency_nice > MAX_LATENCY_NICE) + return -EINVAL; + if (attr->sched_latency_nice < MIN_LATENCY_NICE) + return -EINVAL; + } + if (pi) cpuset_read_lock(); @@ -7360,6 +7376,9 @@ static int __sched_setscheduler(struct task_struct *p, goto change; if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) goto change; + if (attr->sched_flags & SCHED_FLAG_LATENCY_NICE && + attr->sched_latency_nice != p->latency_nice) + goto change; p->sched_reset_on_fork = reset_on_fork; retval = 0; @@ -7448,6 +7467,7 @@ static int __sched_setscheduler(struct task_struct *p, __setscheduler_params(p, attr); __setscheduler_prio(p, newprio); } + __setscheduler_latency(p, attr); __setscheduler_uclamp(p, attr); if (queued) { @@ -7658,6 +7678,9 @@ static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *a size < SCHED_ATTR_SIZE_VER1) return -EINVAL; + if ((attr->sched_flags & SCHED_FLAG_LATENCY_NICE) && + size < SCHED_ATTR_SIZE_VER2) + return -EINVAL; /* * XXX: Do we want to be lenient like existing syscalls; or do we want * to be strict and return an error on out-of-bounds values? @@ -7895,6 +7918,8 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, get_params(p, &kattr); kattr.sched_flags &= SCHED_FLAG_ALL; + kattr.sched_latency_nice = p->latency_nice; + #ifdef CONFIG_UCLAMP_TASK /* * This could race with another potential updater, but this is fine diff --git a/tools/include/uapi/linux/sched.h b/tools/include/uapi/linux/sched.h index 3bac0a8ceab2..ecc4884bfe4b 100644 --- a/tools/include/uapi/linux/sched.h +++ b/tools/include/uapi/linux/sched.h @@ -132,6 +132,7 @@ struct clone_args { #define SCHED_FLAG_KEEP_PARAMS 0x10 #define SCHED_FLAG_UTIL_CLAMP_MIN 0x20 #define SCHED_FLAG_UTIL_CLAMP_MAX 0x40 +#define SCHED_FLAG_LATENCY_NICE 0X80 #define SCHED_FLAG_KEEP_ALL (SCHED_FLAG_KEEP_POLICY | \ SCHED_FLAG_KEEP_PARAMS) @@ -143,6 +144,7 @@ struct clone_args { SCHED_FLAG_RECLAIM | \ SCHED_FLAG_DL_OVERRUN | \ SCHED_FLAG_KEEP_ALL | \ - SCHED_FLAG_UTIL_CLAMP) + SCHED_FLAG_UTIL_CLAMP | \ + SCHED_FLAG_LATENCY_NICE) #endif /* _UAPI_LINUX_SCHED_H */ -- 2.17.1