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From: BurnZeZ@feline.systems
To: 9front@9front.org
Subject: Re: [9front] time
Date: Sun, 12 Aug 2018 22:28:28 +0000	[thread overview]
Message-ID: <6c11e603325ca644a5068fd3d0f30df1@rebk.znet> (raw)
In-Reply-To: <543D9EFF84178350A65D710955EDB98B@felloff.net>

On Sun Aug 12 21:08:00 GMT 2018, cinap_lenrek@felloff.net wrote:
> of course it does. theres nothing special about exec. the accounting
> starts when the *process* is created, not after exec(). also, it is
> hard to know what you consider time spend execing. the exec itself
> just reads the programs a.out header and creates the segments.
> the pages get faulted in during the runtime of the program *after*
> exec did its job.

I’ve been tricked.


> internally, user/kernel time accounting works by hzclock()
> just incrementing a per process counter of ticks. which is
> not very precise and processes can evade time being accounted
> by yielding so they'd miss the timer interrupt.

Are there any other reasons for the real time count to become erratic
or inconsistent?
How does this work on a multi-core machine?


> so there is an opportunity here that when going to 64 bit,
> we could improve the time accounting and change the unit
> to nanoseconds as well...

Might be better than staying with milli, since nsec() sort of
promotes nano anyway.


  reply	other threads:[~2018-08-12 22:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-12 21:07 cinap_lenrek
2018-08-12 22:28 ` BurnZeZ [this message]
  -- strict thread matches above, loose matches on Subject: below --
2018-08-13  7:45 cinap_lenrek
2018-08-12 19:11 cinap_lenrek
2018-08-12 20:49 ` BurnZeZ

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