On Sat, Sep 13, 2014 at 9:42 AM, Andrew Morton wrote: > On Sat, 13 Sep 2014 09:26:49 +0400 Konstantin Khlebnikov wrote: > >> > >> > Did we really need to put the BalloonPages count into per-zone vmstat, >> > global vmstat and /proc/meminfo? Seems a bit overkillish - why so >> > important? >> >> Balloon grabs random pages, their distribution among numa nodes might >> be important. >> But I know nobody who uses numa-aware vm together with ballooning. >> >> Probably it's better to drop per-zone vmstat and line from meminfo, >> global vmstat counter should be enough. > > Yes, the less we add the better - we can always add stuff later if > there is a demonstrated need. Ok. (I guess incremental patches are more convenient for you) Here is two fixes which remove redundant per-zone counters and adds three vmstat counters: "balloon_inflate", "balloon_deflate" and "balloon_migrate". This statistic seems more useful than current state snapshot. Size of balloon is just a difference between "inflate" and "deflate". > >> > >> > Consuming another page flag is a big deal. We keep on nearly running >> > out and one day we'll run out for real. page-flags-layout.h is >> > incomprehensible. How many flags do we have left (worst-case) with this >> > change? Is there no other way? Needs extraordinary justification, >> > please. >> >> PageBalloon is not a page flags, it's like PageBuddy -- special state >> of _mapcount (-256 in this case). >> The same was in v1 and is written in the comment above. > > oop sorry, I got confused about KPF_BALLOON.