From: Peter Zijlstra <peterz@infradead.org>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Yu Liao <liaoyu15@huawei.com>,
fweisbec@gmail.com, mingo@kernel.org, liwei391@huawei.com,
mirsad.todorovac@alu.unizg.hr, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] tick/nohz: fix data races in get_cpu_idle_time_us()
Date: Tue, 31 Jan 2023 20:59:05 +0100 [thread overview]
Message-ID: <Y9lzCaC2k/Un64O3@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <Y9lfe54aoCWlmyqy@p183>
On Tue, Jan 31, 2023 at 09:35:39PM +0300, Alexey Dobriyan wrote:
> > Seriously this procfs accuracy is the least of the problems and if this
> > would be the only issue then we could trivially fix it by declaring that
> > the procfs output might go backwards.
>
> Declarations on l-k are meaningless.
Not really, we often do the -EWONTFIX thing.
> > If there would be a real reason to ensure monotonicity there then we could
> > easily do that in the readout code.
>
> People expect it to be monotonic. I wrote this test fully expecting
> that /proc/uptime is monotonic. It didn't ever occured to me that
> idletime can go backwards (nor uptime, but uptime is not buggy).
People want ponies too -- people will just have to cope with not having
ponies.
next prev parent reply other threads:[~2023-01-31 19:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-28 2:00 [PATCH RFC] tick/nohz: fix data races in get_cpu_idle_time_us() Yu Liao
2023-01-31 14:44 ` Thomas Gleixner
2023-01-31 18:35 ` Alexey Dobriyan
2023-01-31 19:59 ` Peter Zijlstra [this message]
2023-01-31 19:57 ` Peter Zijlstra
2023-01-31 21:11 ` Frederic Weisbecker
2023-02-01 9:03 ` Peter Zijlstra
2023-02-08 15:19 ` [PATCH] timers/nohz: Restructure and reshuffle struct tick_sched Frederic Weisbecker
[not found] ` <20230201045302.316-1-hdanton@sina.com>
2023-02-01 12:02 ` [PATCH RFC] tick/nohz: fix data races in get_cpu_idle_time_us() Frederic Weisbecker
[not found] ` <20230201140117.539-1-hdanton@sina.com>
2023-02-01 14:28 ` Frederic Weisbecker
2023-02-06 7:03 ` kernel test robot
2023-02-07 5:25 ` Mirsad Goran Todorovac
2023-02-07 8:03 ` Mirsad Goran Todorovac
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