Re: [PATCH v10 00/16] Volatile Ranges v10

[Minchan Kim <minchan@kernel.org>]

On Mon, Jan 27, 2014 at 04:42:27PM -0800, John Stultz wrote:
> On 01/27/2014 04:12 PM, Minchan Kim wrote:
> > On Mon, Jan 27, 2014 at 05:23:17PM -0500, KOSAKI Motohiro wrote:
> >> - Your number only claimed the effectiveness anon vrange, but not file vrange.
> > Yes. It's really problem as I said.
> > From the beginning, John Stultz wanted to promote vrange-file to replace
> > android's ashmem and when I heard usecase of vrange-file, it does make sense
> > to me so that's why I'd like to unify them in a same interface.
> >
> > But the problem is lack of interesting from others and lack of time to
> > test/evaluate it. I'm not an expert of userspace so actually I need a bit
> > help from them who require the feature but at a moment,
> > but I don't know who really want or/and help it.
> >
> > Even, Android folks didn't have any interest on vrange-file.
> 
> Just as a correction here. I really don't think this is the case, as
> Android's use definitely relies on file based volatility. It might be
> more fair to say there hasn't been very much discussion from Android
> developers on the particulars of the file volatility semantics (out
> possibly not having any particular objections, or more-likely, being a
> bit too busy to follow the all various theoretical tangents we've
> discussed).
> 
> But I'd not want anyone to get the impression that anonymous-only
> volatility would be sufficient for Android's needs.

Right. Thanks for the correction.

> 
> 
> (And to further clarify here, since this can be confusing... 
> shmem/tmpfs-only file volatility *would* be sufficient, despite that
> technically being anonymous backed memory. The key issue is we need to
> be able to share the volatility between processes.)
> 
> 
> > So, we might drop vrange-file part in this patchset if it's really headache.
> > But let's discuss further because still I believe it's valuable feature to
> > keep instead of dropping.
> 
> If it helps gets interest in reviewing this, I'm ok with deferring
> (tmpfs) file volatility, so folks can get comfortable with anonymous
> volatility. But I worry its too critical a feature to ignore.

Yes. I don't want to drop it without more discussion with real user
of it but the problem is it's very hard to find one to have extra time
to discuss it.


> 
> thanks
> -john
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

-- 
Kind regards,
Minchan Kim

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>