On 02/12/2015 08:32 AM, Joonsoo Kim wrote: > > 1) Break non-overlapped zone assumption > CMA regions could be spread to all memory range, so, to keep all of them > into one zone, span of ZONE_CMA would be overlap to other zones'. >From patch 13/16 ut seems to me that indeed the ZONE_CMA spans the area of all other zones. This seems very inefficient for e.g. compaction scanners, which will repeatedly skip huge amounts of pageblocks that don't belong to ZONE_CMA. Could you instead pick only a single zone on a node from which you steal the pages? That would allow to keep the span low. Another disadvantage I see is that to allocate from ZONE_CMA you will have now to reclaim enough pages within the zone itself. I think think the cma allocation supports migrating pages from ZONE_CMA to the adjacent non-CMA zone, which would be equivalent to migration from MIGRATE_CMA pageblocks to the rest of the zone? > I'm not sure that there is an assumption about possibility of zone overlap > But, if ZONE_CMA is introduced, this assumption becomes reality > so we should deal with this situation. I investigated most of sites > that iterates pfn on certain zone and found that they normally doesn't > consider zone overlap. I tried to handle these cases by myself in the > early of this series. I hope that there is no more site that depends on > non-overlap zone assumption when iterating pfn on certain zone. > > I passed boot test on x86, ARM32 and ARM64. I did some stress tests > on x86 and there is no problem. Feel free to enjoy and please give me > a feedback. :) > > This patchset is based on v3.18. > > Thanks. > > [1] https://lkml.org/lkml/2014/5/28/64 > [2] https://lkml.org/lkml/2014/11/4/55 > [3] https://lkml.org/lkml/2014/10/15/623 > [4] https://lkml.org/lkml/2014/5/30/320 > > > Joonsoo Kim (16): > mm/page_alloc: correct highmem memory statistics > mm/writeback: correct dirty page calculation for highmem > mm/highmem: make nr_free_highpages() handles all highmem zones by > itself > mm/vmstat: make node_page_state() handles all zones by itself > mm/vmstat: watch out zone range overlap > mm/page_alloc: watch out zone range overlap > mm/page_isolation: watch out zone range overlap > power: watch out zone range overlap > mm/cma: introduce cma_total_pages() for future use > mm/highmem: remove is_highmem_idx() > mm/page_alloc: clean-up free_area_init_core() > mm/cma: introduce new zone, ZONE_CMA > mm/cma: populate ZONE_CMA and use this zone when GFP_HIGHUSERMOVABLE > mm/cma: print stealed page count > mm/cma: remove ALLOC_CMA > mm/cma: remove MIGRATE_CMA > > arch/x86/include/asm/sparsemem.h | 2 +- > arch/x86/mm/highmem_32.c | 3 + > include/linux/cma.h | 9 ++ > include/linux/gfp.h | 31 +++--- > include/linux/mempolicy.h | 2 +- > include/linux/mm.h | 1 + > include/linux/mmzone.h | 58 +++++----- > include/linux/page-flags-layout.h | 2 + > include/linux/vm_event_item.h | 8 +- > include/linux/vmstat.h | 26 +---- > kernel/power/snapshot.c | 15 +++ > lib/show_mem.c | 2 +- > mm/cma.c | 70 ++++++++++-- > mm/compaction.c | 6 +- > mm/highmem.c | 12 +- > mm/hugetlb.c | 2 +- > mm/internal.h | 3 +- > mm/memory_hotplug.c | 3 + > mm/mempolicy.c | 3 +- > mm/page-writeback.c | 8 +- > mm/page_alloc.c | 223 +++++++++++++++++++++---------------- > mm/page_isolation.c | 14 ++- > mm/vmscan.c | 2 +- > mm/vmstat.c | 16 ++- > 24 files changed, 317 insertions(+), 204 deletions(-) > -- 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>