On Wed, Jun 01, 2016 at 02:41:51PM -0700, Andrew Morton wrote: > On Wed, 1 Jun 2016 08:21:09 +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 easy fork fail. > > > > The problem was fragmentation caused by zram and GPU driver mainly. > > With memory pressure, their pages were spread out all of pageblock and > > it cannot be migrated with current compaction algorithm which supports > > only LRU pages. In the end, compaction cannot work well so reclaimer > > shrinks all of working set pages. It made system very slow and even to > > fail to fork easily which requires order-[2 or 3] allocations. > > > > Other pain point is that they cannot use CMA memory space so when OOM > > kill happens, I can see many free pages in CMA area, which is not > > memory efficient. In our product which has big CMA memory, it reclaims > > zones too exccessively to allocate GPU and zram page although there are > > lots of free space in CMA so system becomes very slow easily. > > But this isn't presently implemented for GPU drivers or for CMA, yes? For GPU driver, Gioh implemented but it was proprietary so couldn't contribute. For CMA, [zram: use __GFP_MOVABLE for memory allocation] added __GFP_MOVABLE for zsmalloc page allocation so it can use CMA area automatically now. > > What's the story there? -- 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>