Re: remap_file_pages() use

From: Kirill A. Shutemov
Date: Mon May 19 2014 - 11:53:45 EST


Armin Rigo wrote:
> Hi Kirill,
>
> On 19 May 2014 17:17, Kirill A. Shutemov
> <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
> > IIUC PyPy uses the syscall in some early prototype and looks like guys are
> > okay to rework it to mmap() if default sysctl_max_map_count will be high
> > enough.
>
> Yes, we can switch easily if needed. The syscall is not in any
> "production" version yet.
>
> Please note that "high enough" in this context means higher than
> 2**20. We need it high enough to handle regularly 10-20% of all the
> RAM used by each program. If I count correctly, at 20%, 2**20 fails
> above 20GB. In general I would suggest to use a default limit that
> depends on the amount of RAM (+swap) available.

Is it nessesary to remap in 4k chunks for you?
What about 64k chunks? Or something bigger?

This way you can scale down required number of VMAs to something more
reasonable.

--
Kirill A. Shutemov
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