Re: [PATCH v6] add MAP_UNLOCKED mmap flag

From: Gleb Natapov
Date: Tue Jan 19 2010 - 08:26:49 EST


On Tue, Jan 19, 2010 at 03:18:11PM +0200, Pekka Enberg wrote:
> On Tue, Jan 19, 2010 at 2:48 PM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote:
> > Gleb. How about using MADV_SEQUENTIAL on guest memory?
> > It makes that pages of guest are moved into inactive reclaim list more
> > fast. It means it is likely to swap out faster than other pages if it
> > isn't hit during inactive list.
>
> Yeah, something like that but we don't want the readahead. OTOH, it's
> not clear what Gleb's real problem is. Are the guest address spaces
> anonymous or file backed?
Anonymous.

> Which parts of the emulator are swapped out
> that are causing the problem?
I don't want anything that can be used during guest runtime to be
swapped out. And I run 2G guest in 512M container, so eventually
everything is swapped out :)

> Maybe it's a VM balancing issue that
> mlock papers over?
>
There is no problem. I do measurements on how host swapping affects
guest and I don't want qemu code to be swapped out.

--
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/