Re: 2.6.33 pagemap endless read loop

From: AmÃrico Wang
Date: Tue Jan 12 2010 - 10:30:30 EST


On Sun, Jan 10, 2010 at 01:37:02PM +0100, Andi Kleen wrote:
>> Are you sure
>
>I don't know if it's really endless, but it's doing a good emulation
>of it if it's not.
>
>>
>> On my 32bit machine, it runs for a long time, but finally exits.
>
>That was on 64bit.
>
>proc01 had accumulated several minutes of CPU time when I stopped it.
>
>> From the document of pagemap, it is the mapping of all the virtual pages
>> of a process, on x86-32, it should be 4G/4K = 1024*1024 pages, also
>
>Only the mapped ones surely?
>
>Right now it looks like it dumps all the holes and that obviously
>will never finish on 64bit which has 47bits of address space.
>

Hmm, could you please try:

time cat /proc/self/pagemap >/dev/null

? Is it much faster than:

time cat /proc/self/pagemap

?

Thanks!
--
Live like a child, think like the god.

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