Messages in this thread | | | Date | Fri, 11 Jan 2013 08:58:18 +1100 | From | paul.szabo@sydney ... | Subject | [RFC] Reproducible OOM with partial workaround |
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Dear Linux-MM,
On a machine with i386 kernel and over 32GB RAM, an OOM condition is reliably obtained simply by writing a few files to some local disk e.g. with: n=0; while [ $n -lt 99 ]; do dd bs=1M count=1024 if=/dev/zero of=x$n; ((n=$n+1)); done Crash usually occurs after 16 or 32 files written. Seems that the problem may be avoided by using mem=32G on the kernel boot, and that it occurs with any amount of RAM over 32GB.
I developed a workaround patch for this particular OOM demo, dropping filesystem caches when about to exhaust lowmem. However, subsequently I observed OOM when running many processes (as yet I do not have an easy-to-reproduce demo of this); so as I suspected, the essence of the problem is not with FS caches.
Could you please help in finding the cause of this OOM bug?
Please see http://bugs.debian.org/695182 for details, in particular my workaround patch http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=101;att=1;bug=695182
(Please reply to me directly, as I am not a subscriber to the linux-mm mailing list.)
Thanks, Paul
Paul Szabo psz@maths.usyd.edu.au http://www.maths.usyd.edu.au/u/psz/ School of Mathematics and Statistics University of Sydney Australia
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