Hi Seth, On Tue, Apr 09, 2013 at 03:52:36PM -0500, Seth Jennings wrote: > On 04/08/2013 08:36 PM, Minchan Kim wrote: > > On Tue, Apr 09, 2013 at 10:27:19AM +0900, Minchan Kim wrote: > >> Hi Dan, > >> > >> On Mon, Apr 08, 2013 at 09:32:38AM -0700, Dan Magenheimer wrote: > >>>> From: Minchan Kim [mailto:minchan@xxxxxxxxxx] > >>>> Sent: Monday, April 08, 2013 12:01 AM > >>>> Subject: [PATCH] mm: remove compressed copy from zram in-memory > >>> > >>> (patch removed) > >>> > >>>> Fragment ratio is almost same but memory consumption and compile time > >>>> is better. I am working to add defragment function of zsmalloc. > >>> > >>> Hi Minchan -- > >>> > >>> I would be very interested in your design thoughts on > >>> how you plan to add defragmentation for zsmalloc. In > >> > >> What I can say now about is only just a word "Compaction". > >> As you know, zsmalloc has a transparent handle so we can do whatever > >> under user. Of course, there is a tradeoff between performance > >> and memory efficiency. I'm biased to latter for embedded usecase. > >> > >> And I might post it because as you know well, zsmalloc > > > > Incomplete sentense, > > > > I might not post it until promoting zsmalloc because as you know well, > > zsmalloc/zram's all new stuffs are blocked into staging tree. > > Even if we could add it into staging, as you know well, staging is where > > every mm guys ignore so we end up needing another round to promote it. sigh. > > Yes. The lack of compaction/defragmentation support in zsmalloc has not > been raised as an obstacle to mainline acceptance so I think we should > wait to add new features to a yet-to-be accepted codebase. > > Also, I think this feature is more important to zram than it is to > zswap/zcache as they can do writeback to free zpages. In other words, > the fragmentation is a transient issue for zswap/zcache since writeback > to the swap device is possible. Other benefit derived from compaction work is that we can pick a zpage from zspage and move it into somewhere. It means core mm could control pages in zsmalloc freely. > > Thanks, > Seth > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>