From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 2DF778E0097 for ; Thu, 24 Jan 2019 16:15:52 -0500 (EST) Received: by mail-pf1-f197.google.com with SMTP id b17so5668879pfc.11 for ; Thu, 24 Jan 2019 13:15:52 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id az5sor31957935plb.11.2019.01.24.13.15.50 for (Google Transport Security); Thu, 24 Jan 2019 13:15:51 -0800 (PST) From: Suren Baghdasaryan Subject: [PATCH v3 4/5] psi: rename psi fields in preparation for psi trigger addition Date: Thu, 24 Jan 2019 13:15:17 -0800 Message-Id: <20190124211518.244221-5-surenb@google.com> In-Reply-To: <20190124211518.244221-1-surenb@google.com> References: <20190124211518.244221-1-surenb@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: gregkh@linuxfoundation.org Cc: tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, axboe@kernel.dk, dennis@kernel.org, dennisszhou@gmail.com, mingo@redhat.com, peterz@infradead.org, akpm@linux-foundation.org, corbet@lwn.net, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, Suren Baghdasaryan Renaming psi_group structure member fields used for calculating psi totals and averages for clear distinction between them and trigger-related fields that will be added next. Signed-off-by: Suren Baghdasaryan --- include/linux/psi_types.h | 15 ++++++++------- kernel/sched/psi.c | 26 ++++++++++++++------------ 2 files changed, 22 insertions(+), 19 deletions(-) diff --git a/include/linux/psi_types.h b/include/linux/psi_types.h index 762c6bb16f3c..47757668bdcb 100644 --- a/include/linux/psi_types.h +++ b/include/linux/psi_types.h @@ -69,20 +69,21 @@ struct psi_group_cpu { }; struct psi_group { - /* Protects data updated during an aggregation */ - struct mutex stat_lock; + /* Protects data used by the aggregator */ + struct mutex update_lock; /* Per-cpu task state & time tracking */ struct psi_group_cpu __percpu *pcpu; - /* Periodic aggregation state */ - u64 total_prev[NR_PSI_STATES - 1]; - u64 last_update; - u64 next_update; struct delayed_work clock_work; - /* Total stall times and sampled pressure averages */ + /* Total stall times observed */ u64 total[NR_PSI_STATES - 1]; + + /* Running pressure averages */ + u64 avg_total[NR_PSI_STATES - 1]; + u64 avg_last_update; + u64 avg_next_update; unsigned long avg[NR_PSI_STATES - 1][3]; }; diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 2262d920295f..c366503ba135 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -172,9 +172,9 @@ static void group_init(struct psi_group *group) for_each_possible_cpu(cpu) seqcount_init(&per_cpu_ptr(group->pcpu, cpu)->seq); - group->next_update = sched_clock() + psi_period; + group->avg_next_update = sched_clock() + psi_period; INIT_DELAYED_WORK(&group->clock_work, psi_update_work); - mutex_init(&group->stat_lock); + mutex_init(&group->update_lock); } void __init psi_init(void) @@ -277,7 +277,7 @@ static bool update_stats(struct psi_group *group) int cpu; int s; - mutex_lock(&group->stat_lock); + mutex_lock(&group->update_lock); /* * Collect the per-cpu time buckets and average them into a @@ -318,7 +318,7 @@ static bool update_stats(struct psi_group *group) /* avgX= */ now = sched_clock(); - expires = group->next_update; + expires = group->avg_next_update; if (now < expires) goto out; if (now - expires > psi_period) @@ -331,14 +331,14 @@ static bool update_stats(struct psi_group *group) * But the deltas we sample out of the per-cpu buckets above * are based on the actual time elapsing between clock ticks. */ - group->next_update = expires + ((1 + missed_periods) * psi_period); - period = now - (group->last_update + (missed_periods * psi_period)); - group->last_update = now; + group->avg_next_update = expires + ((1 + missed_periods) * psi_period); + period = now - (group->avg_last_update + (missed_periods * psi_period)); + group->avg_last_update = now; for (s = 0; s < NR_PSI_STATES - 1; s++) { u32 sample; - sample = group->total[s] - group->total_prev[s]; + sample = group->total[s] - group->avg_total[s]; /* * Due to the lockless sampling of the time buckets, * recorded time deltas can slip into the next period, @@ -358,11 +358,11 @@ static bool update_stats(struct psi_group *group) */ if (sample > period) sample = period; - group->total_prev[s] += sample; + group->avg_total[s] += sample; calc_avgs(group->avg[s], missed_periods, sample, period); } out: - mutex_unlock(&group->stat_lock); + mutex_unlock(&group->update_lock); return nonidle_total; } @@ -390,8 +390,10 @@ static void psi_update_work(struct work_struct *work) u64 now; now = sched_clock(); - if (group->next_update > now) - delay = nsecs_to_jiffies(group->next_update - now) + 1; + if (group->avg_next_update > now) { + delay = nsecs_to_jiffies( + group->avg_next_update - now) + 1; + } schedule_delayed_work(dwork, delay); } } -- 2.20.1.321.g9e740568ce-goog