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From: Ferry Toth <ftoth@telfort.nl>
To: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Mike Galbraith <efault@gmx.de>, linux-kernel@vger.kernel.org
Subject: Re: DOS by unprivileged user
Date: Mon, 30 Apr 2018 12:00:16 +0200	[thread overview]
Message-ID: <12218300.6oQjICIiUq@ferry-quad> (raw)
In-Reply-To: <20180425155459.5a4e40e0@alans-desktop>

Op woensdag 25 april 2018 16:54:59 CEST schreef Alan Cox:
> > > I think memory allocation and io waits can't be decoupled from
> > > scheduling as they are now.  
> > 
> > The scheduler is not decoupled from either, it is intimately involved
> > in both.  However, none of the decision making smarts for either reside
> > in the scheduler, nor should they.
> 
> It belongs in both.
> 
> Classical Unix systems never had this problem because they respond to
> thrashing by ensuring that all processes consumed CPU and made some
> progress. Linux handles it by thrashing itself to dealth while BSD always
> handled it by moving from paging more towards swapping and behaving like
> a swap bound batch machine.
> 
> Linux thrashes itself to death, the classic BSD algorithn instead throws
> fairness out of the window under extreme load to prevent it. It might take
> a few seconds but at least you will get your prompt back.
> 
> Alan
> 
I haven\0t tried BSD.

But when I was young I allocated 10MB on a HP9000 (UX) with 1MB of RAM. People wanted to launch me out of the window (18th floor).

I did not want to say Unix was better, only with so much emphasis on security I'\0m surprised how easy it is for a regular user to bring linux to on it\0s knees.

  parent reply	other threads:[~2018-04-30 10:00 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-19 19:13 Ferry Toth
2018-04-20  4:46 ` Mike Galbraith
2018-04-20  8:39   ` Ferry Toth
2018-04-20 12:37     ` Mike Galbraith
2018-04-22 10:16 ` Pavel Machek
2018-04-22 17:43   ` vcaputo
2018-04-23  0:27     ` Michal Hocko
2018-04-23  7:13       ` Pavel Machek
     [not found] ` <4285098.DEWjdbWF2X@delfion>
     [not found]   ` <1524325275.8078.2.camel@gmx.de>
     [not found]     ` <6057755.ozdVOybsI6@delfion>
2018-04-23  8:04       ` Mike Galbraith
2018-04-25 14:54         ` Alan Cox
2018-04-25 16:21           ` Mike Galbraith
2018-04-25 16:50           ` Mike Galbraith
2018-04-30 10:00           ` Ferry Toth [this message]
2018-04-30 10:35             ` Miguel Ojeda

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