From nobody Wed Feb 11 06:30:44 2026 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 71C11C83F2F for ; Thu, 31 Aug 2023 20:31:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347414AbjHaUbL (ORCPT ); Thu, 31 Aug 2023 16:31:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232420AbjHaUbK (ORCPT ); Thu, 31 Aug 2023 16:31:10 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6CCE1721 for ; Thu, 31 Aug 2023 13:30:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B43D4B823C5 for ; Thu, 31 Aug 2023 20:30:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48E03C433C7; Thu, 31 Aug 2023 20:30:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693513836; bh=aQ4nhpCB5+LdRupp8kpZ3PR8UVwoGTWspDaPEo1f0cQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qoj9BWv/Sabgffn1ain9/MQNbJdU3u7u3ak+NMiR3/HXmJ6pBRPdoI+Vei+nLCmYI 6M6v70LigBsh44jVsb6W3jYxb6pm6g/424+nmE8Wb/1VvkKVtpGDRBxWHE3pxTjpXD C2ITYtrjHpakSsMiKVDsSH0KCbUf0tZ48tVE87diB8q7Mi2sPA8i5CmGaqa8PY1bSq lhRWjUXWEFJ7b1kC/IMgfdQhnVHlSROWlL5CWN6JkeZS29awh8JZUV0AnVix6L2Xph R86IPcMWO86QSiE5CbyfwK7XHtAvKDHaqu6OJsfA9bq1hUkijaopJQeMTUyVYVI4+9 9ShIwcDzQyPww== From: Daniel Bristot de Oliveira To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot Cc: Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , linux-kernel@vger.kernel.org, Luca Abeni , Tommaso Cucinotta , Thomas Gleixner , Joel Fernandes , Vineeth Pillai , Shuah Khan , bristot@kernel.org, Phil Auld Subject: [PATCH v4 7/7] sched/fair: Fair server interface Date: Thu, 31 Aug 2023 22:28:58 +0200 Message-Id: X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add an interface for fair server setup on debugfs. Each rq have three file under /sys/kernel/debug/sched/rq/CPU{ID}: - fair_server_runtime: set runtime in ns - fair_server_period: set period in ns - fair_server_defer: on/off for the defer mechanism Signed-off-by: Daniel Bristot de Oliveira --- kernel/sched/debug.c | 177 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 4c3d0d9f3db6..dad7d5d073ef 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -333,8 +333,183 @@ static const struct file_operations sched_debug_fops = =3D { .release =3D seq_release, }; =20 +static ssize_t +sched_fair_server_runtime_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long cpu =3D (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq =3D cpu_rq(cpu); + unsigned long flags; + u64 runtime; + int err; + + err =3D kstrtoull_from_user(ubuf, cnt, 10, &runtime); + if (err) + return err; + + raw_spin_rq_lock_irqsave(rq, flags); + if (runtime > rq->fair_server.dl_period) + err =3D -EINVAL; + else + rq->fair_server.dl_runtime =3D runtime; + raw_spin_rq_unlock_irqrestore(rq, flags); + + if (err) + return err; + + *ppos +=3D cnt; + return cnt; +} + +static int sched_fair_server_runtime_show(struct seq_file *m, void *v) +{ + unsigned long cpu =3D (unsigned long) m->private; + struct rq *rq =3D cpu_rq(cpu); + + seq_printf(m, "%llu\n", rq->fair_server.dl_runtime); + return 0; +} + +static int sched_fair_server_runtime_open(struct inode *inode, struct file= *filp) +{ + return single_open(filp, sched_fair_server_runtime_show, inode->i_private= ); +} + +static const struct file_operations fair_server_runtime_fops =3D { + .open =3D sched_fair_server_runtime_open, + .write =3D sched_fair_server_runtime_write, + .read =3D seq_read, + .llseek =3D seq_lseek, + .release =3D single_release, +}; + +static unsigned int fair_server_period_max =3D (1 << 22) * NSEC_PER_USEC; = /* ~4 seconds */ +static unsigned int fair_server_period_min =3D (100) * NSEC_PER_USEC; = /* 100 us */ + +static ssize_t +sched_fair_server_period_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long cpu =3D (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq =3D cpu_rq(cpu); + unsigned long flags; + u64 period; + int err; + + err =3D kstrtoull_from_user(ubuf, cnt, 10, &period); + if (err) + return err; + + if (period < fair_server_period_min || period > fair_server_period_max) + return -EINVAL; + + raw_spin_rq_lock_irqsave(rq, flags); + if (period < rq->fair_server.dl_runtime) + err =3D -EINVAL; + else + rq->fair_server.dl_period =3D period; + raw_spin_rq_unlock_irqrestore(rq, flags); + + if (err) + return err; + + *ppos +=3D cnt; + return cnt; +} + +static int sched_fair_server_period_show(struct seq_file *m, void *v) +{ + unsigned long cpu =3D (unsigned long) m->private; + struct rq *rq =3D cpu_rq(cpu); + + seq_printf(m, "%llu\n", rq->fair_server.dl_period); + return 0; +} + +static int sched_fair_server_period_open(struct inode *inode, struct file = *filp) +{ + return single_open(filp, sched_fair_server_period_show, inode->i_private); +} + +static const struct file_operations fair_server_period_fops =3D { + .open =3D sched_fair_server_period_open, + .write =3D sched_fair_server_period_write, + .read =3D seq_read, + .llseek =3D seq_lseek, + .release =3D single_release, +}; + +static ssize_t +sched_fair_server_defer_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long cpu =3D (long) ((struct seq_file *) filp->private_data)->private; + struct rq *rq =3D cpu_rq(cpu); + unsigned long flags; + u64 defer; + int err; + + err =3D kstrtoull_from_user(ubuf, cnt, 10, &defer); + if (err) + return err; + + if (defer < 0 || defer > 1) + return -EINVAL; + + raw_spin_rq_lock_irqsave(rq, flags); + rq->fair_server_defer =3D defer; + raw_spin_rq_unlock_irqrestore(rq, flags); + + *ppos +=3D cnt; + return cnt; +} + +static int sched_fair_server_defer_show(struct seq_file *m, void *v) +{ + unsigned long cpu =3D (unsigned long) m->private; + struct rq *rq =3D cpu_rq(cpu); + + seq_printf(m, "%d\n", rq->fair_server_defer); + return 0; +} + +static int sched_fair_server_defer_open(struct inode *inode, struct file *= filp) +{ + return single_open(filp, sched_fair_server_defer_show, inode->i_private); +} + +static const struct file_operations fair_server_defer_fops =3D { + .open =3D sched_fair_server_defer_open, + .write =3D sched_fair_server_defer_write, + .read =3D seq_read, + .llseek =3D seq_lseek, + .release =3D single_release, +}; + static struct dentry *debugfs_sched; =20 +void debugfs_fair_server_init(void) +{ + long cpu; + struct dentry *rq_dentry; + + rq_dentry =3D debugfs_create_dir("rq", debugfs_sched); + if (!rq_dentry) + return; + + for_each_possible_cpu(cpu) { + struct dentry *d_cpu; + char buf[32]; + + snprintf(buf, sizeof(buf), "cpu%ld", cpu); + d_cpu =3D debugfs_create_dir(buf, rq_dentry); + + debugfs_create_file("fair_server_runtime", 0644, d_cpu, (void *) cpu, &f= air_server_runtime_fops); + debugfs_create_file("fair_server_period", 0644, d_cpu, (void *) cpu, &fa= ir_server_period_fops); + debugfs_create_file("fair_server_defer", 0644, d_cpu, (void *) cpu, &fai= r_server_defer_fops); + } +} + static __init int sched_init_debug(void) { struct dentry __maybe_unused *numa; @@ -374,6 +549,8 @@ static __init int sched_init_debug(void) =20 debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops= ); =20 + debugfs_fair_server_init(); + return 0; } late_initcall(sched_init_debug); --=20 2.40.1