From: Vinayak Menon <vinmenon@codeaurora.org>
To: Johannes Weiner <hannes@cmpxchg.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-block@vger.kernel.org, cgroups@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
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>,
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 16:33:24 +0530 [thread overview]
Message-ID: <87060553-2e09-2e2a-13a2-a91345d6df30@codeaurora.org> (raw)
In-Reply-To: <20180507210135.1823-7-hannes@cmpxchg.org>
On 5/8/2018 2:31 AM, Johannes Weiner wrote:
> +static void psi_group_update(struct psi_group *group, int cpu, u64 now,
> + unsigned int clear, unsigned int set)
> +{
> + enum psi_state state = PSI_NONE;
> + struct psi_group_cpu *groupc;
> + unsigned int *tasks;
> + unsigned int to, bo;
> +
> + groupc = per_cpu_ptr(group->cpus, cpu);
> + tasks = groupc->tasks;
> +
> + /* Update task counts according to the set/clear bitmasks */
> + for (to = 0; (bo = ffs(clear)); to += bo, clear >>= bo) {
> + int idx = to + (bo - 1);
> +
> + if (tasks[idx] == 0 && !psi_bug) {
> + printk_deferred(KERN_ERR "psi: task underflow! cpu=%d idx=%d tasks=[%u %u %u %u]\n",
> + cpu, idx, tasks[0], tasks[1],
> + tasks[2], tasks[3]);
> + psi_bug = 1;
> + }
> + tasks[idx]--;
> + }
> + for (to = 0; (bo = ffs(set)); to += bo, set >>= bo)
> + tasks[to + (bo - 1)]++;
> +
> + /* Time in which tasks wait for the CPU */
> + state = PSI_NONE;
> + if (tasks[NR_RUNNING] > 1)
> + state = PSI_SOME;
> + time_state(&groupc->res[PSI_CPU], state, now);
> +
> + /* Time in which tasks wait for memory */
> + state = PSI_NONE;
> + if (tasks[NR_MEMSTALL]) {
> + if (!tasks[NR_RUNNING] ||
> + (cpu_curr(cpu)->flags & PF_MEMSTALL))
> + state = PSI_FULL;
> + else
> + state = PSI_SOME;
> + }
> + time_state(&groupc->res[PSI_MEM], state, now);
> +
> + /* Time in which tasks wait for IO */
> + state = PSI_NONE;
> + if (tasks[NR_IOWAIT]) {
> + if (!tasks[NR_RUNNING])
> + state = PSI_FULL;
> + else
> + state = PSI_SOME;
> + }
> + time_state(&groupc->res[PSI_IO], state, now);
> +
> + /* Time in which tasks are non-idle, to weigh the CPU in summaries */
> + if (groupc->nonidle)
> + groupc->nonidle_time += now - groupc->nonidle_start;
> + groupc->nonidle = tasks[NR_RUNNING] ||
> + tasks[NR_IOWAIT] || tasks[NR_MEMSTALL];
> + if (groupc->nonidle)
> + groupc->nonidle_start = now;
> +
> + /* Kick the stats aggregation worker if it's gone to sleep */
> + if (!delayed_work_pending(&group->clock_work))
This causes a crash when the work is scheduled before system_wq is up. In my case when the first
schedule was called from kthreadd. And I had to do this to make it work.
if (keventd_up() && !delayed_work_pending(&group->clock_work))
> + schedule_delayed_work(&group->clock_work, MY_LOAD_FREQ);
> +}
> +
> +void psi_task_change(struct task_struct *task, u64 now, int clear, int set)
> +{
> + struct cgroup *cgroup, *parent;
unused variables
Thanks,
Vinayak
next prev parent reply other threads:[~2018-05-09 11:03 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-07 21:01 [PATCH 0/7] psi: pressure stall information for CPU, memory, and IO 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
2018-05-09 11:03 ` Vinayak Menon [this message]
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
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