Re: reliability of linux-vm subsystem (fwd)

["Benjamin C.R. LaHaise" <blah@kvack.org>]

Please be sure to attribute properly when replying to this =)

>From erik@arthur.ubicom.tudelft.nl Mon Nov 13 08:07:24 2000
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Date:   Mon, 13 Nov 2000 14:06:41 +0100
From:   Erik Mouw <J.A.K.Mouw@ITS.TUDelft.NL>
To:     aprasad@in.ibm.com
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: reliability of linux-vm subsystem
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In-Reply-To: <CA256996.004352F8.00@d73mta05.au.ibm.com>; from aprasad@in.ibm.com on Mon, Nov 13, 2000 at 05:29:48PM +0530
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On Mon, Nov 13, 2000 at 05:29:48PM +0530, aprasad@in.ibm.com wrote:
> When i run following code many times.
> System becomes useless till all of the instance of this programming are
> killed by vmm.

Good, so the OOM killer works.

> Till that time linux doesn't accept any command though it switches from one
> VT to another but its useless.

VT swithing is done by the kernel itself, not by a process.

> The above programme is run as normal user previleges.
> Theoretically load should increase but system should services other users
> too.

No. The system would *like* to service other processes, but it *can't*
because it is trashing.

> but this is not behaving in that way.
> ___________________________________________________________________
> main()
> {
>      char *x[1000];
>      int count=1000,i=0;
>      for(i=0; i <count; i++)
>           x[i] = (char*)malloc(1024*1024*10); /*10MB each time*/
> 
> }
> _______________________________________________________________________
> If i run above programm for 10 times , then system is useless for around
> 5-7minutes on PIII/128MB.

Sounds quite normal to me. If you don't enforce process limits, you
allow a normal user to thrash the system.


Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031,  2600 GA Delft, The Netherlands
Phone: +31-15-2783635  Fax: +31-15-2781843  Email: J.A.K.Mouw@its.tudelft.nl
WWW: http://www-ict.its.tudelft.nl/~erik/

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