Re: Core file size?

From: Jesper Juhl
Date: Fri Dec 01 2006 - 09:41:23 EST


On 30/11/06, linux err <linux_err@xxxxxxxxx> wrote:
Does anyone know what determines the size of a core
dump? I have a process running out of memory (it
allocates about 3GB) - but the size of core varies
(between 2-3GB) depending on how much the process
wrote on the allocated memory.


Makes perfect sense. The core dump contains the memory of the process,
so if the process has 3GB in use then the core file will be 3GB.

You can limit the size of core dumps with "ulimit -c"


Also, the time it takes to write the core (same size)
varies??

Could be many reasons for that. If the load on the machine varies the
time to perform any given action will vary as well.


I briefly looked at elf_core_dump and get_user_pages()
in binfmt_elf.c. Is there any documentation on this?
Or anyone knows how it works?

http://x86.ddj.com/ftp/manuals/tools/elf.pdf
http://en.wikipedia.org/wiki/Core_dump


--
Jesper Juhl <jesper.juhl@xxxxxxxxx>
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