Re: Commenting out out_of_memory() function in __alloc_pages()

[Robert Hancock <hancockr@shaw.ca>]

Abu M. Muttalib wrote:
> Hi,
> 
> I am getting the Out of memory.
> 
> To circumvent the problem, I have commented the call to "out_of_memory(),
> and replaced "goto restart" with "goto nopage".
> 
> At "nopage:" lable I have added a call to "schedule()" and then "return
> NULL" after "schedule()".

Bad idea - in the configuration you have, the system may need the 
out-of-memory killer to free up memory, otherwise the system can 
deadlock due to all memory being exhausted.

> 
> I tried the modified kernel with a test application, the test application is
> mallocing memory in a loop. Unlike as expected the process gets killed. On
> second run of the same application I am getting the page allocation failure
> as expected but subsequently the system hangs.
> 
> I am attaching the test application and the log herewith.
> 
> I am getting this exception with kernel 2.6.13. With kernel
> 2.4.19-rmka7-pxa1 there was no problem.
> 
> Why its so? What can I do to alleviate the OOM problem?

Please see Documentation/vm/overcommit-accounting in the kernel source tree.

-- 
Robert Hancock      Saskatoon, SK, Canada
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