Is this possible?

[Bob]

** Reply to message from Joel Rees <joel.rees at gmail.com> on Thu, 6 Oct 2016
18:55:32 +0900

> On Thu, Oct 6, 2016 at 6:09 PM, Bob <ubuntu-qygzanxc at listemail.net> wrote:
> > ** Reply to message from Peter Silva <peter at bsqt.homeip.net> on Wed, 5 Oct 2016
> > 20:27:08 -0400
> >
> >> On Wed, Oct 5, 2016 at 4:24 PM, Bob <ubuntu-qygzanxc at listemail.net> wrote:
> >> > ** Reply to message from Peter Silva <peter at bsqt.homeip.net> on Wed, 5 Oct 2016
> >> > 07:46:09 -0400
> >> >
> >> >> "swap is maxed out"
> >> >>
> >> >> uh... if that's true, it doesn't matter how much or what kind of cpu
> >> >> you have, it will crawl and die from time to time.   your machine is
> >> >> sitting in wait i/o.
> >> >
> >> > true
> >> >
> >> >
> >> >>   When "swap is maxed out" the kernel will kill
> >> >> processes randomly, (OOM Killer) you cannot expect a PC with it's
> >> >> memory (including swap space) entirely full to run correctly.
> >> >
> >> > If this is what Linux does that is a very bad design.  I would never have
> >> > thought the system would do that.
> >> >
> >>
> >> OK, I said randomly, I meant that loosely, in terms of the user being
> >> unlikely to understand what is being killed or why.   An explanation
> >> of the algorithm is here:   https://linux-mm.org/OOM_Killer
> >
> > Thanks for the link.
> >
> >
> >> It isn't bad design, it's completely normal and a logical consequence
> >> of an aggressively modern virtual memory system.   Detailed
> >> explanation here:
> >>
> >> http://www.linuxdevcenter.com/pub/a/linux/2006/11/30/linux-out-of-memory.html
> >
> > I still think it is a bad design.
> 
> In mainframe land, the sysop doesn't let a bunch of poorly designed
> applications run together. (And the sysop may, in fact, arbitrarily
> kill low priority processes, especially those that seem to be
> misbehaving.)
> 
> > I come from many many years of mainframe experience and am fairly new to Linux
> > but I still think it is a bad design.
> 
> Welcome to the cutting edge, where the most popular applications are
> written by programmers who have never heard or thought of designing an
> application to degrade gracefully.
> 
> And much of the OS, especially "utility" class tools, are written by
> programmers who just finally heard the magic words yesterday. (And we
> shall not mention systemd. And, no, MSWindows is not any better about
> this.)
> 
> >> Example, you start up two processes (same executable) they start out the same,
> >> so they share memory, then a process needs to write to a memory page,
> >> so that page cannot be shared anymore, OS needs to allocate a new
> >> page.  Nobody malloc'd anything, and it was way faster to start up if
> >> you don't copy everything just because two processes are using them.
> >> copy-on-write...
> >>
> >> Example, when you do a malloc, and the value isn't initialized, it may
> >> just succeed (as long as the memory would fit into process and/or
> >> virtual memory limits.)  when the process actually writes to it,
> >> ahh... then you need it to really exist, but if you don't actually
> >> have the memory (and/or swap) available... (b)OOM.
> >>
> >> People are better off not overloading their systems, and never
> >> encountering OOM, but Linux is actually as smart as possible given a
> >> really poor situation.
> >
> > I agree that overloading a system is bad but it seems many people here advocate
> > setting swap to zero or memory size.  I am used to a large swap size to allow
> > for peak memory usage and that is how I set up my system.  My current swap size
> > is 4 times my memory size and consider that a bit small.  I have never tracked
> > max swap usage so I don't know what it has been but current swap usage is 60mb.
> > I have some long running number cruncher programs but limit the number running
> > to the number of cores.  I have not noticed any performance problems using
> > several CLI and/or GUI programs while everything else is running.
> >
> 
> Definitely concur with that.
> 
> Twice RAM is my minimum, and I usually go with five times.
> 
> Of course, if I actually have a process set that consistently has as
> much swap as RAM allocated, I know I'm in for a thrashing.
> 
> (Unless most of that is a class of program that tends to keep a lot of
> inactive and not currently referenced state around -- all the active
> data is in the top several GB of heap and heap grows and shrinks as it
> parses its way through a data set, leaving a lot of stuff on the
> bottom of heap that won't get accessed for a while, or similar
> patterns.)
> 
> But most PC software is "architected" by engineers who wouldn't have a
> clue about what I just said. PC software is more than a little like
> pulp fiction or pop music. Not inherently bad, just a different style.
> And you need to take a break from it periodically. :)
> 
> > --
> > Robert Blair
> >
> >
> > The inherent vice of capitalism is the unequal sharing of the blessings.  The inherent blessing of socialism is the equal sharing of misery.  -- Winston Churchill
> >
> 
> -- 
> Joel Rees
> 
> I'm imagining I'm a novelist:
> http://joel-rees-economics.blogspot.com/2016/04/economics-101-novel-rough-draft-index.html

I can't argue with anything you said especially the lack of good system and/or
program design.

I have been allergic to Windows since its very beginning.  Have been using OS/2
since 1989 and have just recently started to use Linux since I don't know how
much longer OS/2 is going to be around.

-- 
Robert Blair


Giving money and power to government is like giving whiskey and car keys to teenage boys.  -- P.J. O'Rourke, Civil Libertarian