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 3437DC433FE for ; Tue, 15 Nov 2022 17:20:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237742AbiKORUD (ORCPT ); Tue, 15 Nov 2022 12:20:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229890AbiKORTS (ORCPT ); Tue, 15 Nov 2022 12:19:18 -0500 Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A10D28E06 for ; Tue, 15 Nov 2022 09:19:12 -0800 (PST) Received: by mail-wr1-x435.google.com with SMTP id y16so25429168wrt.12 for ; Tue, 15 Nov 2022 09:19:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=references:in-reply-to:message-id:date:subject:cc:to:from:from:to :cc:subject:date:message-id:reply-to; bh=ykXig/7XYkSW6Dkf0nyYluv6HE0QJzXE3P7uP1TrGB4=; b=wyOX2yEa2/MbyLgnbvcqOW23Zx89ycJpBs4987F8pDWadxSSrwJZWacT0K4X+6RenJ vVTOqRrn1zdMc9PynswpdGXTxQqRhJNT/xlDbhJSBjxP8I1Ad4g9ckwYjfV/d2vGyBwm 1SBL1F2I2BirHq7WO+3/CtUkKBnp10TAcw22IGGeu+wwrA+a2Rso7hpcmOhUlyoP69rf bhwRGif9HhYCLGbjKXlOt1+X2XLP9nRBgbDS/f8JVOlXUCsUUszwLwd4NHaRyjidGc0m n5n/O2R3YyUaEnqOI/PUFpglQ4G04g1T7getnbftyaW7+CGo+vFJTne59NyxTFCa74/h liCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=references:in-reply-to:message-id:date:subject:cc:to:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ykXig/7XYkSW6Dkf0nyYluv6HE0QJzXE3P7uP1TrGB4=; b=qj4kRadcKUX8lQvDHc2G9+rNN7KQ5Tg38LW8iY1zn6rOhJturno9K+YlWHRbngTgcL ZXvc02iAzpfuBeV0FFQ0odQhvCX0gtcKN/skCBOviqcHfAak0LXMbbYLLCGQhhbYH3I4 +zjhkM4z/ids0JauFClkjGRa76Wm7tQcJlktCttmIMshoJwngc5n9Qw6CEaK5TB1eZkY UzIiOIC7oG9dYF6YIlIdoWg6JCFx+qfn6NRccBkS2/HbhPf4lxyhKXgAOi7X/wruKUTS haSO/sPRqa94zKFBnBNGDmxVkAkNZdyqs04jxEyFIvxpHWxeHkvyKOnGVOyG222l8jg2 b1gQ== X-Gm-Message-State: ANoB5plS6EhcAdjF6QKfKQKz3WlJbMpwiWinFQE/aqpBEdOVKBBO1WbQ vsCEvB0H4eU547V48cQ3PC8/sy+smQZBkg== X-Google-Smtp-Source: AA0mqf4oFfok5jL+YpUZVWqvut8Le0wvdvUkCNuknFwDnQvsdheDgjSQN25NVOA2tzxLigrimAtiDg== X-Received: by 2002:adf:e4c1:0:b0:236:4ba1:fb2d with SMTP id v1-20020adfe4c1000000b002364ba1fb2dmr11855364wrm.570.1668532751530; Tue, 15 Nov 2022 09:19:11 -0800 (PST) Received: from localhost.localdomain ([2a01:e0a:f:6020:91c8:7496:8b73:811f]) by smtp.gmail.com with ESMTPSA id bg40-20020a05600c3ca800b003cf78aafdd7sm16846461wmb.39.2022.11.15.09.19.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 09:19:10 -0800 (PST) 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: qyousef@layalina.io, chris.hyser@oracle.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, timj@gnu.org, kprateek.nayak@amd.com, yu.c.chen@intel.com, youssefesmat@chromium.org, joel@joelfernandes.org, Vincent Guittot Subject: [PATCH v9 6/9] sched/fair: Add sched group latency support Date: Tue, 15 Nov 2022 18:18:48 +0100 Message-Id: <20221115171851.835-7-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20221115171851.835-1-vincent.guittot@linaro.org> References: <20221115171851.835-1-vincent.guittot@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Task can set its latency priority with sched_setattr(), which is then used to set the latency offset of its sched_enity, but sched group entities still have the default latency offset value. Add a latency.nice field in cpu cgroup controller to set the latency priority of the group similarly to sched_setattr(). The latency priority is then used to set the offset of the sched_entities of the group. Signed-off-by: Vincent Guittot --- Documentation/admin-guide/cgroup-v2.rst | 10 +++++ kernel/sched/core.c | 52 +++++++++++++++++++++++++ kernel/sched/fair.c | 33 ++++++++++++++++ kernel/sched/sched.h | 4 ++ 4 files changed, 99 insertions(+) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index dc254a3cb956..93a73663a5f7 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1118,6 +1118,16 @@ All time durations are in microseconds. values similar to the sched_setattr(2). This maximum utilization value is used to clamp the task specific maximum utilization clamp. + cpu.latency.nice + A read-write single value file which exists on non-root + cgroups. The default is "0". + + The nice value is in the range [-20, 19]. + + This interface file allows reading and setting latency using the + same values used by sched_setattr(2). The latency_nice of a group is + used to limit the impact of the latency_nice of a task outside the + group. Memory diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b2b8cb6c08cd..9f6700f812ea 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10967,6 +10967,47 @@ static int cpu_idle_write_s64(struct cgroup_subsys_state *css, { return sched_group_set_idle(css_tg(css), idle); } + +static s64 cpu_latency_nice_read_s64(struct cgroup_subsys_state *css, + struct cftype *cft) +{ + int prio, delta, last_delta = INT_MAX; + s64 weight; + + weight = css_tg(css)->latency_offset * NICE_LATENCY_WEIGHT_MAX; + weight = div_s64(weight, get_sleep_latency(false)); + + /* Find the closest nice value to the current weight */ + for (prio = 0; prio < ARRAY_SIZE(sched_latency_to_weight); prio++) { + delta = abs(sched_latency_to_weight[prio] - weight); + if (delta >= last_delta) + break; + last_delta = delta; + } + + return LATENCY_TO_NICE(prio-1); +} + +static int cpu_latency_nice_write_s64(struct cgroup_subsys_state *css, + struct cftype *cft, s64 nice) +{ + s64 latency_offset; + long weight; + int idx; + + if (nice < MIN_LATENCY_NICE || nice > MAX_LATENCY_NICE) + return -ERANGE; + + idx = NICE_TO_LATENCY(nice); + idx = array_index_nospec(idx, LATENCY_NICE_WIDTH); + weight = sched_latency_to_weight[idx]; + + latency_offset = weight * get_sleep_latency(false); + latency_offset = div_s64(latency_offset, NICE_LATENCY_WEIGHT_MAX); + + return sched_group_set_latency(css_tg(css), latency_offset); +} + #endif static struct cftype cpu_legacy_files[] = { @@ -10981,6 +11022,11 @@ static struct cftype cpu_legacy_files[] = { .read_s64 = cpu_idle_read_s64, .write_s64 = cpu_idle_write_s64, }, + { + .name = "latency.nice", + .read_s64 = cpu_latency_nice_read_s64, + .write_s64 = cpu_latency_nice_write_s64, + }, #endif #ifdef CONFIG_CFS_BANDWIDTH { @@ -11198,6 +11244,12 @@ static struct cftype cpu_files[] = { .read_s64 = cpu_idle_read_s64, .write_s64 = cpu_idle_write_s64, }, + { + .name = "latency.nice", + .flags = CFTYPE_NOT_ON_ROOT, + .read_s64 = cpu_latency_nice_read_s64, + .write_s64 = cpu_latency_nice_write_s64, + }, #endif #ifdef CONFIG_CFS_BANDWIDTH { diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0e80e65113bd..75c0a8d203c3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12158,6 +12158,7 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) goto err; tg->shares = NICE_0_LOAD; + tg->latency_offset = 0; init_cfs_bandwidth(tg_cfs_bandwidth(tg)); @@ -12256,6 +12257,9 @@ void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, } se->my_q = cfs_rq; + + se->latency_offset = tg->latency_offset; + /* guarantee group entities always have weight */ update_load_set(&se->load, NICE_0_LOAD); se->parent = parent; @@ -12386,6 +12390,35 @@ int sched_group_set_idle(struct task_group *tg, long idle) return 0; } +int sched_group_set_latency(struct task_group *tg, s64 latency) +{ + int i; + + if (tg == &root_task_group) + return -EINVAL; + + if (abs(latency) > sysctl_sched_latency) + return -EINVAL; + + mutex_lock(&shares_mutex); + + if (tg->latency_offset == latency) { + mutex_unlock(&shares_mutex); + return 0; + } + + tg->latency_offset = latency; + + for_each_possible_cpu(i) { + struct sched_entity *se = tg->se[i]; + + WRITE_ONCE(se->latency_offset, latency); + } + + mutex_unlock(&shares_mutex); + return 0; +} + #else /* CONFIG_FAIR_GROUP_SCHED */ void free_fair_sched_group(struct task_group *tg) { } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 7292652731d0..c3735a34d394 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -383,6 +383,8 @@ struct task_group { /* A positive value indicates that this is a SCHED_IDLE group. */ int idle; + /* latency constraint of the group. */ + int latency_offset; #ifdef CONFIG_SMP /* @@ -493,6 +495,8 @@ extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); extern int sched_group_set_idle(struct task_group *tg, long idle); +extern int sched_group_set_latency(struct task_group *tg, s64 latency); + #ifdef CONFIG_SMP extern void set_task_rq_fair(struct sched_entity *se, struct cfs_rq *prev, struct cfs_rq *next); -- 2.17.1