mmap() question

[Dmitry Sivachenko]

On 12.10.2013, at 18:14, Konstantin Belousov <kostikbel at gmail.com> wrote:

>> 
>> First I tried with some swap space configured.  The OS started to swap out my process after it reached about 20GB which is also not what I expected:  what is the reason to swap out regions of read-only mmap()ed files?  Is it the expected behaviour?
>> 
> How did you concluded that the pages from your r/o mappings were paged out ?
> VM never does this.  Only anonymous memory could be written to swap file,
> including the shadow pages for the writeable COW mappings.  I suspect that
> you have another 20GB of something used on the machine meantime.
> 


Yes, sorry, I tried again with swap space configured and it is really some other processes which are swapping out:
sshd, other user's shells, etc.


>> 
>>> 
>>> Below is the prototype patch, against HEAD.  It is not applicable to
>>> stable, please use HEAD kernel for test.
>> 



I tried your patch with stable/10 system and I can confirm that my process is not killed anymore because of OOM.