Re: [PATCH v6] add MAP_UNLOCKED mmap flag

From: Gleb Natapov
Date: Mon Jan 18 2010 - 13:20:41 EST


On Mon, Jan 18, 2010 at 08:09:26PM +0200, Pekka Enberg wrote:
> Hi Gleb,
>
> On Mon, Jan 18, 2010 at 7:08 PM, Gleb Natapov <gleb@xxxxxxxxxx> wrote:
> >> "Greater control" is not an argument for adding a new API that needs
> >> to be maintained forever, a real world use case is.
> >>
> > If there is real world use case for mlockall() there is real use case for
> > this too. People seems to be trying to convince me that I don't need
> > mlockall() without proposing alternatives. The only alternative I see
> > lock everything from userspace.
> >
> >> And yes, this stuff needs to be in the changelog. Whether you want to
> >> spell it out or post an URL to some previous discussion is up to you.
> > The discussion was here just a couple of days ago. Here is the link
> > were I describe my use case: http://marc.info/?l=linux-mm&m=126345374125942&w=2
> > If you think it needs to be spelled out in commit log I'll do it.
>
> So this is a performance thing? Btw, is there are reason you can't use
> plain mlock() for it as suggested by Peter earlier?
>
I can't realistically chase every address space mapping changes and mlock
new areas. The only way other then mlockall() is to use custom memory
allocator that allocates mlocked memory.

--
Gleb.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/