Re: [Lsf] IO less throttling and cgroup aware writeback (Was: Re: Preliminary Agenda and Activities for LSF)

Wu Fengguang
2011-04-19T14:26:44Z

On Fri, Apr 08, 2011 at 11:58:41AM +1000, Dave Chinner wrote:
> On Wed, Apr 06, 2011 at 07:10:17PM +0200, Jan Kara wrote:
> > On Wed 06-04-11 12:08:05, Vivek Goyal wrote:
> > > On Wed, Apr 06, 2011 at 11:37:15AM -0400, Vivek Goyal wrote:
> > Well, I wouldn't bother too much with kswapd handling. MM people plan to
> > get rid of writeback from direct reclaim and just remove the dirty page
> > from LRU and recycle it once flusher thread writes it...
>
> kswapd is not in the direct reclaim path - it's the background
> memory reclaim path. Writeback from direct reclaim is a problem
> because of stack usage, and that problem doesn't exist for kswapd.

FYI the IO initiated from pageout() in kswapd/direct reclaim can
mostly be transfered to the flushers.

Here is the early RFC patch, and I'll submit an update soon.

http://www.spinics.net/lists/linux-mm/msg09199.html

Thanks,
Fengguang