On Wed, Mar 30, 2016 at 04:11:41PM -0700, Andrew Morton wrote: > On Wed, 30 Mar 2016 16:11:59 +0900 Minchan Kim <minchan@xxxxxxxxxx> wrote: > > > Recently, I got many reports about perfermance degradation > > in embedded system(Android mobile phone, webOS TV and so on) > > and failed to fork easily. > > > > The problem was fragmentation caused by zram and GPU driver > > pages. Their pages cannot be migrated so compaction cannot > > work well, either so reclaimer ends up shrinking all of working > > set pages. It made system very slow and even to fail to fork > > easily. > > > > Other pain point is that they cannot work with CMA. > > Most of CMA memory space could be idle(ie, it could be used > > for movable pages unless driver is using) but if driver(i.e., > > zram) cannot migrate his page, that memory space could be > > wasted. In our product which has big CMA memory, it reclaims > > zones too exccessively although there are lots of free space > > in CMA so system was very slow easily. > > > > To solve these problem, this patch try to add facility to > > migrate non-lru pages via introducing new friend functions > > of migratepage in address_space_operation and new page flags. > > > > (isolate_page, putback_page) > > (PG_movable, PG_isolated) > > > > For details, please read description in > > "mm/compaction: support non-lru movable page migration". > > OK, I grabbed all these. > > I wonder about testing coverage during the -next period. How many > people are likely to exercise these code paths in a serious way before > it all hits mainline? I asked this patchset to production team in my company for stress testing. They alaways catch zram/zsmalloc bugs I have missed so I hope they help me well, too. About ballooning part, I hope Rafael Aquini get a time to review and test it. Other than that, IOW, linux-next will have a enough time to test common migration part modification, I guess. :) Thanks. -- 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>