On 03/05/2015 05:53 PM, Vlastimil Babka wrote: > 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 I don't think... > 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> > -- 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>