All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-block@vger.kernel.org, cgroups@vger.kernel.org,
	Ingo Molnar <mingo@redhat.com>,
	Andrew Morton <akpm@linuxfoundation.org>,
	Tejun Heo <tj@kernel.org>, Balbir Singh <bsingharora@gmail.com>,
	Mike Galbraith <efault@gmx.de>, Oliver Yang <yangoliver@me.com>,
	Shakeel Butt <shakeelb@google.com>, xxx xxx <x.qendo@gmail.com>,
	Taras Kondratiuk <takondra@cisco.com>,
	Daniel Walker <danielwa@cisco.com>,
	Vinayak Menon <vinmenon@codeaurora.org>,
	Ruslan Ruslichenko <rruslich@cisco.com>,
	kernel-team@fb.com
Subject: Re: [PATCH 6/7] psi: pressure stall information for CPU, memory, and IO
Date: Wed, 9 May 2018 12:55:05 +0200	[thread overview]
Message-ID: <20180509105505.GQ12217@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180507210135.1823-7-hannes@cmpxchg.org>

On Mon, May 07, 2018 at 05:01:34PM -0400, Johannes Weiner wrote:

> @@ -28,10 +28,14 @@ static inline int sched_info_on(void)
>  	return 1;
>  #elif defined(CONFIG_TASK_DELAY_ACCT)
>  	extern int delayacct_on;
> -	return delayacct_on;
> -#else
> -	return 0;
> +	if (delayacct_on)
> +		return 1;
> +#elif defined(CONFIG_PSI)
> +	extern int psi_disabled;
> +	if (!psi_disabled)
> +		return 1;
>  #endif
> +	return 0;
>  }

> diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
> index 8aea199a39b4..cb4a68bcf37a 100644
> --- a/kernel/sched/stats.h
> +++ b/kernel/sched/stats.h
> @@ -55,12 +55,90 @@ static inline void rq_sched_info_depart  (struct rq *rq, unsigned long long delt
>  # define   schedstat_val_or_zero(var)	0
>  #endif /* CONFIG_SCHEDSTATS */
>  
> +#ifdef CONFIG_PSI
> +/*
> + * PSI tracks state that persists across sleeps, such as iowaits and
> + * memory stalls. As a result, it has to distinguish between sleeps,
> + * where a task's runnable state changes, and requeues, where a task
> + * and its state are being moved between CPUs and runqueues.
> + */
> +static inline void psi_enqueue(struct task_struct *p, u64 now)
> +{
> +	int clear = 0, set = TSK_RUNNING;
> +
> +	if (p->state == TASK_RUNNING || p->sched_psi_wake_requeue) {
> +		if (p->flags & PF_MEMSTALL)
> +			set |= TSK_MEMSTALL;
> +		p->sched_psi_wake_requeue = 0;
> +	} else {
> +		if (p->in_iowait)
> +			clear |= TSK_IOWAIT;
> +	}
> +
> +	psi_task_change(p, now, clear, set);
> +}
> +static inline void psi_dequeue(struct task_struct *p, u64 now)
> +{
> +	int clear = TSK_RUNNING, set = 0;
> +
> +	if (p->state == TASK_RUNNING) {
> +		if (p->flags & PF_MEMSTALL)
> +			clear |= TSK_MEMSTALL;
> +	} else {
> +		if (p->in_iowait)
> +			set |= TSK_IOWAIT;
> +	}
> +
> +	psi_task_change(p, now, clear, set);
> +}
> +static inline void psi_ttwu_dequeue(struct task_struct *p)
> +{
> +	/*
> +	 * Is the task being migrated during a wakeup? Make sure to
> +	 * deregister its sleep-persistent psi states from the old
> +	 * queue, and let psi_enqueue() know it has to requeue.
> +	 */
> +	if (unlikely(p->in_iowait || (p->flags & PF_MEMSTALL))) {
> +		struct rq_flags rf;
> +		struct rq *rq;
> +		int clear = 0;
> +
> +		if (p->in_iowait)
> +			clear |= TSK_IOWAIT;
> +		if (p->flags & PF_MEMSTALL)
> +			clear |= TSK_MEMSTALL;
> +
> +		rq = __task_rq_lock(p, &rf);
> +		update_rq_clock(rq);
> +		psi_task_change(p, rq_clock(rq), clear, 0);
> +		p->sched_psi_wake_requeue = 1;
> +		__task_rq_unlock(rq, &rf);
> +	}
> +}

That all seems to be missing psi_disabled tests.. Yes I know it's
burried down in psi_task_change() somewhere, but that's really (too)
late.

(also, you seem to be conserving whitespace; typically we have an empty
lines between functions)

  parent reply	other threads:[~2018-05-09 10:55 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-07 21:01 [PATCH 0/7] " Johannes Weiner
2018-05-07 21:01 ` [PATCH 1/7] mm: workingset: don't drop refault information prematurely Johannes Weiner
2018-05-07 21:01 ` [PATCH 2/7] mm: workingset: tell cache transitions from workingset thrashing Johannes Weiner
2018-05-07 21:01 ` [PATCH 3/7] delayacct: track delays from thrashing cache pages Johannes Weiner
2018-05-07 21:01 ` [PATCH 4/7] sched: loadavg: consolidate LOAD_INT, LOAD_FRAC, CALC_LOAD Johannes Weiner
2018-05-07 21:01 ` [PATCH 5/7] sched: loadavg: make calc_load_n() public Johannes Weiner
2018-05-09  9:49   ` Peter Zijlstra
2018-05-10 13:46     ` Johannes Weiner
2018-05-07 21:01 ` [PATCH 6/7] psi: pressure stall information for CPU, memory, and IO Johannes Weiner
2018-05-08  0:42   ` Randy Dunlap
2018-05-08 14:06     ` Johannes Weiner
2018-05-08  1:35   ` kbuild test robot
2018-05-08  3:04   ` kbuild test robot
2018-05-08 14:05     ` Johannes Weiner
2018-05-09  9:59   ` Peter Zijlstra
2018-05-10 13:49     ` Johannes Weiner
2018-05-09 10:04   ` Peter Zijlstra
2018-05-10 14:10     ` Johannes Weiner
2018-05-09 10:05   ` Peter Zijlstra
2018-05-10 14:13     ` Johannes Weiner
2018-05-09 10:14   ` Peter Zijlstra
2018-05-10 14:18     ` Johannes Weiner
2018-05-09 10:21   ` Peter Zijlstra
2018-05-10 14:24     ` Johannes Weiner
2018-05-09 10:26   ` Peter Zijlstra
2018-05-09 10:46   ` Peter Zijlstra
2018-05-09 11:38     ` Peter Zijlstra
2018-05-10 13:41       ` Johannes Weiner
2018-05-14  8:33         ` Peter Zijlstra
2018-05-09 10:55   ` Peter Zijlstra [this message]
2018-05-09 11:03   ` Vinayak Menon
2018-05-23 13:17     ` Johannes Weiner
2018-05-23 13:19       ` Vinayak Menon
2018-06-07  0:46   ` Suren Baghdasaryan
2018-05-07 21:01 ` [PATCH 7/7] psi: cgroup support Johannes Weiner
2018-05-09 11:07   ` Peter Zijlstra
2018-05-10 14:49     ` Johannes Weiner
2018-05-14 15:39 ` [PATCH 0/7] psi: pressure stall information for CPU, memory, and IO Christopher Lameter
2018-05-14 17:35   ` Bart Van Assche
2018-05-14 18:55   ` Johannes Weiner
2018-05-14 20:15     ` Christopher Lameter
2018-05-26  0:29 ` Suren Baghdasaryan
2018-05-29 18:16   ` Johannes Weiner
2018-05-30 23:32     ` Suren Baghdasaryan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180509105505.GQ12217@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=akpm@linuxfoundation.org \
    --cc=bsingharora@gmail.com \
    --cc=cgroups@vger.kernel.org \
    --cc=danielwa@cisco.com \
    --cc=efault@gmx.de \
    --cc=hannes@cmpxchg.org \
    --cc=kernel-team@fb.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@redhat.com \
    --cc=rruslich@cisco.com \
    --cc=shakeelb@google.com \
    --cc=takondra@cisco.com \
    --cc=tj@kernel.org \
    --cc=vinmenon@codeaurora.org \
    --cc=x.qendo@gmail.com \
    --cc=yangoliver@me.com \
    --subject='Re: [PATCH 6/7] psi: pressure stall information for CPU, memory, and IO' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.