From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suren Baghdasaryan Subject: [PATCH 5/6] psi: rename psi fields in preparation for psi trigger addition Date: Fri, 14 Dec 2018 09:15:07 -0800 Message-ID: <20181214171508.7791-6-surenb@google.com> References: <20181214171508.7791-1-surenb@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=1K/9jxBUhr3ZKbGV/xGf2bm9+2dhfv3m9ZmKXLf2XLM=; b=fdbSosqkmOy+GOJSWJ6aOnhR9OK/6rV7BapjvJttxkHBRPlyq0NYeMod4uZFvdSdmT YuqAwToioC5aXk49M7de1ONOHk9gEsqA7b40kGqvGCau9bMzwLC+BfUXeXcvoRoXY/6z hgN9QIykNobCdulmez5DFg6uIyyRfq7Fv1vwvgOPGumapbEOiO4sslYg8YcjTvKfeWK+ Q14G6m3ZKlkUIUwWpyj24NjsPl7ZP6FsYoj8aqWhtBb9nh7IrV5WHsNgYb40G4jcArqC 8EpvQKL679AjqTo4JLW8cTKtzZMHTArygO9acydjH0zI5ExKr4x7CG85JKpbMTXGdASU 5w/w== In-Reply-To: <20181214171508.7791-1-surenb@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" 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 2c6e9b67b7eb..11b32b3395a2 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 153c0624976b..694edefdd333 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) @@ -268,7 +268,7 @@ static void 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 @@ -309,7 +309,7 @@ static void update_stats(struct psi_group *group) /* avgX= */ now = sched_clock(); - expires = group->next_update; + expires = group->avg_next_update; if (now < expires) goto out; @@ -320,14 +320,14 @@ static void 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 + psi_period; - period = now - group->last_update; - group->last_update = now; + group->avg_next_update = expires + psi_period; + period = now - group->avg_last_update; + 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, @@ -347,11 +347,11 @@ static void 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], sample, period); } out: - mutex_unlock(&group->stat_lock); + mutex_unlock(&group->update_lock); } static void psi_update_work(struct work_struct *work) @@ -375,8 +375,10 @@ static void psi_update_work(struct work_struct *work) update_stats(group); 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); } -- 2.20.0.405.gbc1bbc6f85-goog