Hello, > From: iamjoonsoo.kim@xxxxxxx > To: pintu_agarwal@xxxxxxxxx; linux-mm@xxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linaro-mm-sig@xxxxxxxxxxxxxxxx; ritesh.list@xxxxxxxxx > CC: pintu.k@xxxxxxxxxxx; pintu.k@xxxxxxxxxxx; vishu_1385@xxxxxxxxx; m.szyprowski@xxxxxxxxxxx; mina86@xxxxxxxxxx; ngupta@xxxxxxxxxx; iqbalblr@xxxxxxxxx > Subject: RE: [linux-3.10.17] Could not allocate memory from free CMA areas > Date: Mon, 4 Aug 2014 16:11:00 +0900 > >> Dear Joonsoo, >> >> I tried your changes which are present at the below link. >> https://github.com/JoonsooKim/linux/tree/cma-fix-up-v3.0-next-20140625 >> But unfortunately for me it did not help much. >> After running various apps that uses ION nonmovable memory, it fails to allocate memory after some time. When I see the pagetypeinfo shows lots of CMA pages available and non-movable were very less and thus nonmovable allocation were failing. > > Okay. CMA pages cannot be used for nonmovable memory, so it can fail in above case. > >> However I noticed the failure was little delayed. > > It is good sign. I guess that there is movable/CMA ratio problem. > My patchset uses free CMA pages in certain ratio to free movable page consumption. > If your system doesn't use movable page sufficiently, free CMA pages cannot > be used fully. Could you test with following workaround? > > + if (normal> cma) { > + zone->max_try_normal = pageblock_nr_pages; > + zone->max_try_cma = pageblock_nr_pages; > + } else { > + zone->max_try_normal = pageblock_nr_pages; > + zone->max_try_cma = pageblock_nr_pages; > + } I applied these changes but still the allocations are failing because there are no non-movable memory left in the system. With the changes I noticed that nr_cma_free sometimes becomes almost zero. But in our case Display/Xorg needs to have atleast 8MB of CMA (contiguous) memory of order-8 and order-4 type. CMA:56MB is shared across display,camera,video etc. I think the previous changes are slightly better. My concern is that whether I am applying all you changes or missing some thing. I saw that your kernel version is based on next-20140625 but my kernel version is 3.10.17. And till now I applied only the below changes: https://github.com/JoonsooKim/linux/commit/33a0416b3ac1cd7c88e6b35ee61b4a81a7a14afc But I haven't applied this: https://github.com/JoonsooKim/linux/commit/166b4186d101b190cf50195d841e2189f2743649 (CMA: always treat free cma pages as non-free on watermark checking) These changes have other dependencies which is not present in my kernel version. Like inclusion of ALLOC_FAIR and area->nr_cma_free. Please let me know if these changes are also important for "aggressive alloc changes..." If possible please send me all the patches related to "aggressive cma.." so that I can conclude on my experiment. Further I will share the experimental result from my side. > > 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