On Mon, 9 Apr 2012, Rik van Riel wrote: > On 04/06/2012 04:31 PM, Hugh Dickins wrote: > > On Fri, 6 Apr 2012, Andrew Morton wrote: > > > On Wed, 28 Mar 2012 17:06:21 +0100 > > > Mel Gorman<mgorman@xxxxxxx> wrote: > > > > > > > (cc'ing active people in the thread "[patch 68/92] mm: forbid > > > > lumpy-reclaim > > > > in shrink_active_list()") > > > > > > > > In the interest of keeping my fingers from the flames at LSF/MM, I'm > > > > releasing an RFC for lumpy reclaim removal. > > > > > > I grabbed them, thanks. > > > > I do have a concern with this: I was expecting lumpy reclaim to be > > replaced by compaction, and indeed it is when CONFIG_COMPACTION=y. > > But when CONFIG_COMPACTION is not set, we're back to 2.6.22 in > > relying upon blind chance to provide order>0 pages. > > Is this an issue for any architecture? Dunno about any architecture as a whole; but I'd expect users of SLOB or TINY config options to want to still use lumpy rather than the more efficient but weightier COMPACTION+MIGRATION. Though "size migrate.o compaction.o" on my 32-bit config does not reach 8kB, so maybe it's not a big deal after all. > > I could see NOMMU being unable to use compaction, but Yes, COMPACTION depends on MMU. > chances are lumpy reclaim would be sufficient for that > configuration, anyway... That's an argument for your patch in 3.4-rc, which uses lumpy only when !COMPACTION_BUILD. But here we're worrying about Mel's patch, which removes the lumpy code completely. Hugh -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>