内存规整how

原创 已于 2022-11-30 14:51:06 修改 · 606 阅读 · 0 ·
CC 4.0 BY-SA版权
版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。
文章标签：

#python #大数据 #开发语言

于 2022-11-30 11:08:36 首次发布
这篇博客详细记录了kcompactd在内存紧凑过程中，从尝试到完成的各个阶段，包括mm_compaction尝试、隔离、选择合适的区域和实际迁移操作。重点展示了HwBinder的交互和内存迁移细节，以及最终的迁移结果和后续调度。

kcompactd_do_work->compact_zone

trace_mm_compaction_kcompactd_wake

对应

         kswapd0-114     [003] ..... 15144.528635: mm_compaction_wakeup_kcompactd: nid=0 order=6 classzone_idx=Movable 
     CodecLooper-28886   [001] ..... 15144.528654: mm_compaction_isolate_freepages: range=(0x1bc00 ~ 0x1c000) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [003] ..... 15144.528662: mm_compaction_kcompactd_wake: nid=0 order=6 classzone_idx=HighMem 
      kcompactd0-41      [003] ..... 15144.528665: mm_compaction_suitable: node=0 zone=Normal   order=6 ret=continue
      kcompactd0-41      [003] ..... 15144.528667: mm_compaction_suitable: node=0 zone=Normal   order=6 ret=continue
      kcompactd0-41      [003] ..... 15144.528670: mm_compaction_begin: zone_start

try_to_compact_pages->try_to_compact_pages->compact_zone

 HwBinder:390_1-425     [002] .....   512.216727: mm_compaction_try_to_compact_pages: order=6 gfp_mask=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO priority=1
  HwBinder:390_1-425     [002] .....   512.216733: mm_compaction_deferred: node=0 zone=HighMem  order=6 order_failed=0 consider=60 limit=64
  HwBinder:390_1-425     [002] .....   512.216738: mm_compaction_suitable: node=0 zone=Normal   order=6 ret=continue
  HwBinder:390_1-425     [002] .....   512.216740: mm_compaction_begin: zone_start=0x0 migrate_pfn=0x0 free_pfn=0x2fc00 zone_end=0x30000, mode=sync
  HwBinder:390_1-425     [002] .....   512.216744: mm_compaction_finished: node=0 zone=Normal   order=6 ret=no_suitable_page
  HwBinder:390_1-425     [002] .....   512.216840: mm_compaction_isolate_migratepages: range=(0x1c400 ~ 0x1c800) nr_scanned=821 nr_taken=0
  HwBinder:390_1-425     [002] .....   512.216843: mm_compaction_finished: node=0 zone=Normal   order=6 ret=no_suitable_page
  HwBinder:390_1-425     [002] .....   512.216924: mm_compaction_isolate_migratepages: range=(0x24800 ~ 0x24c00) nr_scanned=989 nr_taken=0
  HwBinder:390_1-425     [002] .....   512.216925: mm_compaction_finished: node=0 zone=Normal   order=6 ret=no_suitable_page
  HwBinder:390_1-425     [002] .....   512.217016: mm_compaction_isolate_migratepages: range=(0x2a000 ~ 0x2a400) nr_scanned=966 nr_taken=14
  HwBinder:390_1-425     [002] .....   512.217141: mm_compaction_isolate_freepages: range=(0x2d000 ~ 0x2d384) nr_scanned=900 nr_taken=0
  HwBinder:390_1-425     [002] .....   512.217146: mm_compaction_isolate_freepages: range=(0x2d385 ~ 0x2d400) nr_scanned=123 nr_taken=2
  HwBinder:390_1-425     [002] .....   512.217262: mm_compaction_isolate_freepages: range=(0x2cc00 ~ 0x2d000) nr_scanned=1024 nr_taken=2
  HwBinder:390_1-425     [002] .....   512.217294: mm_compaction_isolate_freepages: range=(0x2c800 ~ 0x2c860) nr_scanned=96 nr_taken=1
  HwBinder:390_1-425     [002] .....   512.217312: mm_compaction_isolate_freepages: range=(0x2c861 ~ 0x2cc00) nr_scanned=927 nr_taken=0
  HwBinder:390_1-425     [002] .....   512.217377: mm_compaction_isolate_freepages: range=(0x2b400 ~ 0x2b800) nr_scanned=1024 nr_taken=2
  HwBinder:390_1-425     [002] .....   512.217502: mm_compaction_isolate_freepages: range=(0x2a400 ~ 0x2a800) nr_scanned=1024 nr_taken=1
  HwBinder:390_1-425     [002] .....   512.217521: mm_compaction_migratepages: nr_migrated=10 nr_failed=4
  HwBinder:390_1-425     [002] .....   512.217542: mm_compaction_finished: node=0 zone=Normal   order=6 ret=complete
  HwBinder:390_1-425     [002] .....   512.217545: mm_compaction_end: zone_start=0x0 migrate_pfn=0x2a400 free_pfn=0x2a400 zone_end=0x30000, mode=sync status=complete
  HwBinder:390_1-425     [002] .....   512.217548: mm_compaction_defer_compaction: node=0 zone=Normal   order=6 order_failed=6 consider=0 limit=4
      kcompactd0-41      [000] .....   512.509498: mm_compaction_kcompactd_wake: nid=0 order=6 classzone_idx=Normal  
      kcompactd0-41      [000] .....   512.509506: mm_compaction_deferred: node=0 zone=Normal   order=6 order_failed=6 consider=1 limit=4
      kcompactd0-41      [000] .....   512.509509: mm_compaction_kcompactd_sleep: nid=0
         kswapd0-114     [003] .....   512.808897: mm_compaction_suitable: node=0 zone=Normal   order=6 ret=success
         kswapd0-114     [003] .....   512.808905: mm_compaction_suitable: node=0 zone=HighMem  order=6 ret=continue
         kswapd0-114     [003] .....   512.808907: mm_compaction_wakeup_kcompactd: nid=0 order=6 classzone_idx=Movable 
      kcompactd0-41      [000] .....   512.808945: mm_compaction_kcompactd_wake: nid=0 order=6 classzone_idx=HighMem 
      kcompactd0-41      [000] .....   512.808948: mm_compaction_deferred: node=0 zone=Normal   order=6 order_failed=6 consider=2 limit=4
      kcompactd0-41      [000] .....   512.808949: mm_compaction_deferred: node=0 zone=HighMem  order=6 order_failed=0 consider=61 limit=64
      kcompactd0-41      [000] .....   512.808952: mm_compaction_kcompactd_sleep: nid=0
      kcompactd0-41      [000] .....   513.309499: mm_compaction_suitable: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.309507: mm_compaction_begin: zone_start=0x0 migrate_pfn=0x0 free_pfn=0x2fc00 zone_end=0x30000, mode=sync
      kcompactd0-41      [000] .....   513.309510: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.309640: mm_compaction_isolate_migratepages: range=(0x0 ~ 0x400) nr_scanned=992 nr_taken=0
      kcompactd0-41      [000] .....   513.309643: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.309725: mm_compaction_isolate_migratepages: range=(0x400 ~ 0x800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.309726: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.309808: mm_compaction_isolate_migratepages: range=(0x800 ~ 0xc00) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.309809: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.309891: mm_compaction_isolate_migratepages: range=(0xc00 ~ 0x1000) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.309892: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.309975: mm_compaction_isolate_migratepages: range=(0x1000 ~ 0x1400) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.309976: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310058: mm_compaction_isolate_migratepages: range=(0x1400 ~ 0x1800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.310059: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310139: mm_compaction_isolate_migratepages: range=(0x1800 ~ 0x1c00) nr_scanned=995 nr_taken=0
      kcompactd0-41      [000] .....   513.310140: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310183: mm_compaction_isolate_migratepages: range=(0x1c00 ~ 0x2000) nr_scanned=437 nr_taken=0
      kcompactd0-41      [000] .....   513.310184: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310259: mm_compaction_isolate_migratepages: range=(0x2000 ~ 0x2400) nr_scanned=1006 nr_taken=0
      kcompactd0-41      [000] .....   513.310260: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310333: mm_compaction_isolate_migratepages: range=(0x2400 ~ 0x2800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.310334: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310477: mm_compaction_isolate_migratepages: range=(0x2c00 ~ 0x3000) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.310480: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310554: mm_compaction_isolate_migratepages: range=(0x3000 ~ 0x3400) nr_scanned=1021 nr_taken=0
      kcompactd0-41      [000] .....   513.310555: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.310620: mm_compaction_isolate_migratepages: range=(0x3800 ~ 0x3c00) nr_scanned=388 nr_taken=21
      kcompactd0-41      [000] .....   513.310643: mm_compaction_isolate_freepages: range=(0x2f400 ~ 0x2f800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.310660: mm_compaction_isolate_freepages: range=(0x2f000 ~ 0x2f400) nr_scanned=512 nr_taken=0
      kcompactd0-41      [000] .....   513.310690: mm_compaction_isolate_freepages: range=(0x2d400 ~ 0x2d800) nr_scanned=256 nr_taken=5
      kcompactd0-41      [000] .....   513.310719: mm_compaction_isolate_freepages: range=(0x2d000 ~ 0x2d333) nr_scanned=819 nr_taken=16
      kcompactd0-41      [000] .....   513.311022: mm_compaction_migratepages: nr_migrated=21 nr_failed=0
      kcompactd0-41      [000] .....   513.311027: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.311089: mm_compaction_isolate_migratepages: range=(0x3c00 ~ 0x4000) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.311090: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.311148: mm_compaction_isolate_migratepages: range=(0x4000 ~ 0x4400) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.311149: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.311215: mm_compaction_isolate_migratepages: range=(0x4400 ~ 0x4800) nr_scanned=981 nr_taken=8
      kcompactd0-41      [000] .....   513.311226: mm_compaction_isolate_freepages: range=(0x2d333 ~ 0x2d400) nr_scanned=205 nr_taken=3
      kcompactd0-41      [000] .....   513.311236: mm_compaction_isolate_freepages: range=(0x2cc00 ~ 0x2ccbe) nr_scanned=188 nr_taken=6
      kcompactd0-41      [000] .....   513.311370: mm_compaction_migratepages: nr_migrated=0 nr_failed=8
      kcompactd0-41      [000] .....   513.311375: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.311790: mm_compaction_isolate_migratepages: range=(0x4800 ~ 0x4c00) nr_scanned=1012 nr_taken=0
      kcompactd0-41      [000] .....   513.311799: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.311900: mm_compaction_isolate_migratepages: range=(0x4c00 ~ 0x5000) nr_scanned=987 nr_taken=0
      kcompactd0-41      [000] .....   513.311902: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.312111: mm_compaction_isolate_migratepages: range=(0x5000 ~ 0x5400) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.312118: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.312295: mm_compaction_isolate_migratepages: range=(0x5400 ~ 0x5800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.312301: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.312404: mm_compaction_isolate_migratepages: range=(0x5800 ~ 0x5c00) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.312406: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.312622: mm_compaction_isolate_migratepages: range=(0x5c00 ~ 0x6000) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.312628: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.312805: mm_compaction_isolate_migratepages: range=(0x6000 ~ 0x6400) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.312809: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.313065: mm_compaction_isolate_migratepages: range=(0x6400 ~ 0x6800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.313070: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.313192: mm_compaction_isolate_migratepages: range=(0x6800 ~ 0x6c00) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.313195: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.313343: mm_compaction_isolate_migratepages: range=(0x6c00 ~ 0x7000) nr_scanned=459 nr_taken=0
      kcompactd0-41      [000] .....   513.313347: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.313839: mm_compaction_isolate_migratepages: range=(0x7000 ~ 0x7400) nr_scanned=1001 nr_taken=0
      kcompactd0-41      [000] .....   513.313848: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314033: mm_compaction_isolate_migratepages: range=(0x7400 ~ 0x7800) nr_scanned=1009 nr_taken=0
      kcompactd0-41      [000] .....   513.314038: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314150: mm_compaction_isolate_migratepages: range=(0x8400 ~ 0x8800) nr_scanned=1014 nr_taken=3
      kcompactd0-41      [000] .....   513.314243: mm_compaction_migratepages: nr_migrated=0 nr_failed=3
      kcompactd0-41      [000] .....   513.314265: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314349: mm_compaction_isolate_migratepages: range=(0x8800 ~ 0x8c00) nr_scanned=769 nr_taken=0
      kcompactd0-41      [000] .....   513.314351: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314450: mm_compaction_isolate_migratepages: range=(0x8c00 ~ 0x9000) nr_scanned=1000 nr_taken=0
      kcompactd0-41      [000] .....   513.314452: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314676: mm_compaction_isolate_migratepages: range=(0x9000 ~ 0x9400) nr_scanned=999 nr_taken=0
      kcompactd0-41      [000] .....   513.314679: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314788: mm_compaction_isolate_migratepages: range=(0x9400 ~ 0x9800) nr_scanned=1015 nr_taken=3
      kcompactd0-41      [000] .....   513.314832: mm_compaction_migratepages: nr_migrated=3 nr_failed=0
      kcompactd0-41      [000] .....   513.314834: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.314937: mm_compaction_isolate_migratepages: range=(0x9c00 ~ 0xa000) nr_scanned=1011 nr_taken=0
      kcompactd0-41      [000] .....   513.315000: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315104: mm_compaction_isolate_migratepages: range=(0xa000 ~ 0xa400) nr_scanned=1023 nr_taken=0
      kcompactd0-41      [000] .....   513.315106: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315207: mm_compaction_isolate_migratepages: range=(0xa400 ~ 0xa800) nr_scanned=999 nr_taken=0
      kcompactd0-41      [000] .....   513.315209: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315309: mm_compaction_isolate_migratepages: range=(0xa800 ~ 0xac00) nr_scanned=1016 nr_taken=0
      kcompactd0-41      [000] .....   513.315311: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315379: mm_compaction_isolate_migratepages: range=(0xac00 ~ 0xb000) nr_scanned=342 nr_taken=15
      kcompactd0-41      [000] .....   513.315597: mm_compaction_isolate_freepages: range=(0x2ccbe ~ 0x2cdaa) nr_scanned=236 nr_taken=15
      kcompactd0-41      [000] .....   513.315858: mm_compaction_migratepages: nr_migrated=15 nr_failed=0
      kcompactd0-41      [000] .....   513.315865: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315890: mm_compaction_isolate_migratepages: range=(0xb000 ~ 0xb400) nr_scanned=94 nr_taken=0
      kcompactd0-41      [000] .....   513.315893: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315926: mm_compaction_isolate_migratepages: range=(0xb400 ~ 0xb800) nr_scanned=185 nr_taken=0
      kcompactd0-41      [000] .....   513.315929: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.315957: mm_compaction_isolate_migratepages: range=(0xb800 ~ 0xbc00) nr_scanned=147 nr_taken=0
      kcompactd0-41      [000] .....   513.315958: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316062: mm_compaction_isolate_migratepages: range=(0xbc00 ~ 0xc000) nr_scanned=1018 nr_taken=0
      kcompactd0-41      [000] .....   513.316065: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316089: mm_compaction_isolate_migratepages: range=(0xc000 ~ 0xc400) nr_scanned=142 nr_taken=0
      kcompactd0-41      [000] .....   513.316090: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316123: mm_compaction_isolate_migratepages: range=(0xc400 ~ 0xc800) nr_scanned=208 nr_taken=0
      kcompactd0-41      [000] .....   513.316124: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316224: mm_compaction_isolate_migratepages: range=(0xc800 ~ 0xcc00) nr_scanned=929 nr_taken=1
      kcompactd0-41      [000] .....   513.316264: mm_compaction_migratepages: nr_migrated=0 nr_failed=1
      kcompactd0-41      [000] .....   513.316267: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316415: mm_compaction_isolate_migratepages: range=(0xcc00 ~ 0xd000) nr_scanned=950 nr_taken=14
      kcompactd0-41      [000] .....   513.316816: mm_compaction_migratepages: nr_migrated=2 nr_failed=12
      kcompactd0-41      [000] .....   513.316834: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316858: mm_compaction_isolate_migratepages: range=(0xd000 ~ 0xd400) nr_scanned=97 nr_taken=0
      kcompactd0-41      [000] .....   513.316860: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316883: mm_compaction_isolate_migratepages: range=(0xd400 ~ 0xd800) nr_scanned=109 nr_taken=0
      kcompactd0-41      [000] .....   513.316885: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.316988: mm_compaction_isolate_migratepages: range=(0xd800 ~ 0xdc00) nr_scanned=1017 nr_taken=0
      kcompactd0-41      [000] .....   513.316990: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.317020: mm_compaction_isolate_migratepages: range=(0xdc00 ~ 0xe000) nr_scanned=112 nr_taken=4
      kcompactd0-41      [000] .....   513.317079: mm_compaction_migratepages: nr_migrated=4 nr_failed=0
      kcompactd0-41      [000] .....   513.317082: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.317149: mm_compaction_isolate_migratepages: range=(0xe000 ~ 0xe400) nr_scanned=269 nr_taken=24
      kcompactd0-41      [000] .....   513.317196: mm_compaction_isolate_freepages: range=(0x2cdaa ~ 0x2cfe2) nr_scanned=566 nr_taken=24
      kcompactd0-41      [000] .....   513.317689: mm_compaction_migratepages: nr_migrated=24 nr_failed=0
      kcompactd0-41      [000] .....   513.317697: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.318073: mm_compaction_isolate_migratepages: range=(0xe400 ~ 0xe800) nr_scanned=364 nr_taken=0
      kcompactd0-41      [000] .....   513.318079: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.318115: mm_compaction_isolate_migratepages: range=(0xe800 ~ 0xec00) nr_scanned=262 nr_taken=0
      kcompactd0-41      [000] .....   513.318121: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.318156: mm_compaction_isolate_migratepages: range=(0xec00 ~ 0xf000) nr_scanned=253 nr_taken=0
      kcompactd0-41      [000] .....   513.318158: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.318256: mm_compaction_isolate_migratepages: range=(0xf000 ~ 0xf400) nr_scanned=970 nr_taken=0
      kcompactd0-41      [000] .....   513.318258: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.318306: mm_compaction_isolate_migratepages: range=(0xf400 ~ 0xf800) nr_scanned=314 nr_taken=0
      kcompactd0-41      [000] .....   513.318308: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.318350: mm_compaction_isolate_migratepages: range=(0xf800 ~ 0xf860) nr_scanned=33 nr_taken=32
      kcompactd0-41      [000] .....   513.318360: mm_compaction_isolate_freepages: range=(0x2cfe2 ~ 0x2d000) nr_scanned=30 nr_taken=1
      kcompactd0-41      [000] .....   513.318423: mm_compaction_isolate_freepages: range=(0x2c800 ~ 0x2cc00) nr_scanned=1023 nr_taken=24
      kcompactd0-41      [000] .....   513.318436: mm_compaction_isolate_freepages: range=(0x2c000 ~ 0x2c0bd) nr_scanned=189 nr_taken=7
      kcompactd0-41      [000] .....   513.321208: mm_compaction_migratepages: nr_migrated=32 nr_failed=0
      kcompactd0-41      [000] .....   513.321219: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.322484: mm_compaction_isolate_migratepages: range=(0xf860 ~ 0xfc00) nr_scanned=874 nr_taken=813
      kcompactd0-41      [000] .....   513.322545: mm_compaction_isolate_freepages: range=(0x2c0bd ~ 0x2c400) nr_scanned=835 nr_taken=15
      kcompactd0-41      [000] .....   513.322690: mm_compaction_isolate_freepages: range=(0x2bc00 ~ 0x2c000) nr_scanned=1024 nr_taken=18
      kcompactd0-41      [000] .....   513.322747: mm_compaction_isolate_freepages: range=(0x2b800 ~ 0x2bc00) nr_scanned=1024 nr_taken=14
      kcompactd0-41      [000] .....   513.322807: mm_compaction_isolate_freepages: range=(0x2b400 ~ 0x2b800) nr_scanned=1024 nr_taken=26
      kcompactd0-41      [000] .....   513.322933: mm_compaction_isolate_freepages: range=(0x2b000 ~ 0x2b400) nr_scanned=1024 nr_taken=13
      kcompactd0-41      [000] .....   513.322988: mm_compaction_isolate_freepages: range=(0x2ac00 ~ 0x2b000) nr_scanned=1022 nr_taken=19
      kcompactd0-41      [000] .....   513.323058: mm_compaction_isolate_freepages: range=(0x2a800 ~ 0x2ac00) nr_scanned=1021 nr_taken=38
      kcompactd0-41      [000] .....   513.323172: mm_compaction_isolate_freepages: range=(0x2a400 ~ 0x2a800) nr_scanned=1023 nr_taken=20
      kcompactd0-41      [000] .....   513.323242: mm_compaction_isolate_freepages: range=(0x29800 ~ 0x29c00) nr_scanned=1023 nr_taken=36
      kcompactd0-41      [000] .....   513.323322: mm_compaction_isolate_freepages: range=(0x29400 ~ 0x29800) nr_scanned=1023 nr_taken=47
      kcompactd0-41      [000] .....   513.323442: mm_compaction_isolate_freepages: range=(0x28c00 ~ 0x29000) nr_scanned=1024 nr_taken=20
      kcompactd0-41      [000] .....   513.323498: mm_compaction_isolate_freepages: range=(0x28400 ~ 0x28800) nr_scanned=1024 nr_taken=18
      kcompactd0-41      [000] .....   513.323560: mm_compaction_isolate_freepages: range=(0x28000 ~ 0x28400) nr_scanned=1022 nr_taken=34
      kcompactd0-41      [000] .....   513.323750: mm_compaction_isolate_freepages: range=(0x27800 ~ 0x27c00) nr_scanned=1023 nr_taken=29
      kcompactd0-41      [000] .....   513.323780: mm_compaction_isolate_freepages: range=(0x27400 ~ 0x27800) nr_scanned=1024 nr_taken=10
      kcompactd0-41      [000] .....   513.323814: mm_compaction_isolate_freepages: range=(0x26c00 ~ 0x27000) nr_scanned=1024 nr_taken=20
      kcompactd0-41      [000] .....   513.323853: mm_compaction_isolate_freepages: range=(0x26800 ~ 0x26c00) nr_scanned=1024 nr_taken=29
      kcompactd0-41      [000] .....   513.323896: mm_compaction_isolate_freepages: range=(0x26400 ~ 0x26800) nr_scanned=1022 nr_taken=25
      kcompactd0-41      [000] .....   513.323929: mm_compaction_isolate_freepages: range=(0x26000 ~ 0x26400) nr_scanned=1023 nr_taken=17
      kcompactd0-41      [000] .....   513.323969: mm_compaction_isolate_freepages: range=(0x25c00 ~ 0x26000) nr_scanned=1023 nr_taken=25
      kcompactd0-41      [000] .....   513.323996: mm_compaction_isolate_freepages: range=(0x25800 ~ 0x25c00) nr_scanned=1023 nr_taken=12
      kcompactd0-41      [000] .....   513.324030: mm_compaction_isolate_freepages: range=(0x25400 ~ 0x25800) nr_scanned=1023 nr_taken=18
      kcompactd0-41      [000] .....   513.324069: mm_compaction_isolate_freepages: range=(0x25000 ~ 0x25400) nr_scanned=1016 nr_taken=26
      kcompactd0-41      [000] .....   513.324108: mm_compaction_isolate_freepages: range=(0x24c00 ~ 0x25000) nr_scanned=1022 nr_taken=22
      kcompactd0-41      [000] .....   513.324141: mm_compaction_isolate_freepages: range=(0x24400 ~ 0x24800) nr_scanned=1024 nr_taken=14
      kcompactd0-41      [000] .....   513.324180: mm_compaction_isolate_freepages: range=(0x24000 ~ 0x24400) nr_scanned=1023 nr_taken=22
      kcompactd0-41      [000] .....   513.324218: mm_compaction_isolate_freepages: range=(0x23800 ~ 0x23c00) nr_scanned=1023 nr_taken=27
      kcompactd0-41      [000] .....   513.324260: mm_compaction_isolate_freepages: range=(0x23400 ~ 0x23800) nr_scanned=1020 nr_taken=29
      kcompactd0-41      [000] .....   513.324305: mm_compaction_isolate_freepages: range=(0x22c00 ~ 0x23000) nr_scanned=1022 nr_taken=32
      kcompactd0-41      [000] .....   513.324338: mm_compaction_isolate_freepages: range=(0x22800 ~ 0x22c00) nr_scanned=1020 nr_taken=15
      kcompactd0-41      [000] .....   513.324374: mm_compaction_isolate_freepages: range=(0x22400 ~ 0x22800) nr_scanned=1021 nr_taken=18
      kcompactd0-41      [000] .....   513.324414: mm_compaction_isolate_freepages: range=(0x22000 ~ 0x22400) nr_scanned=1018 nr_taken=27
      kcompactd0-41      [000] .....   513.324449: mm_compaction_isolate_freepages: range=(0x21c00 ~ 0x22000) nr_scanned=1024 nr_taken=21
      kcompactd0-41      [000] .....   513.324498: mm_compaction_isolate_freepages: range=(0x21800 ~ 0x21c00) nr_scanned=1023 nr_taken=37
      kcompactd0-41      [000] .....   513.324527: mm_compaction_isolate_freepages: range=(0x21400 ~ 0x21758) nr_scanned=847 nr_taken=21
      kcompactd0-41      [000] .....   513.345474: mm_compaction_migratepages: nr_migrated=813 nr_failed=0
      kcompactd0-41      [000] .....   513.345484: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.345515: mm_compaction_isolate_migratepages: range=(0xfc00 ~ 0xfc21) nr_scanned=33 nr_taken=32
      kcompactd0-41      [000] .....   513.345567: mm_compaction_isolate_freepages: range=(0x21758 ~ 0x21800) nr_scanned=166 nr_taken=7
      kcompactd0-41      [000] .....   513.345657: mm_compaction_isolate_freepages: range=(0x21000 ~ 0x21400) nr_scanned=1016 nr_taken=23
      kcompactd0-41      [000] .....   513.345663: mm_compaction_isolate_freepages: range=(0x20800 ~ 0x20877) nr_scanned=119 nr_taken=2
      kcompactd0-41      [000] .....   513.346416: mm_compaction_migratepages: nr_migrated=32 nr_failed=0
      kcompactd0-41      [000] .....   513.346424: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.347044: mm_compaction_isolate_migratepages: range=(0xfc21 ~ 0x10000) nr_scanned=981 nr_taken=934
      kcompactd0-41      [000] .....   513.347119: mm_compaction_isolate_freepages: range=(0x20877 ~ 0x20c00) nr_scanned=903 nr_taken=32
      kcompactd0-41      [000] .....   513.347159: mm_compaction_isolate_freepages: range=(0x1f800 ~ 0x1fc00) nr_scanned=1016 nr_taken=23
      kcompactd0-41      [000] .....   513.347188: mm_compaction_isolate_freepages: range=(0x1f400 ~ 0x1f800) nr_scanned=1024 nr_taken=7
      kcompactd0-41      [000] .....   513.347222: mm_compaction_isolate_freepages: range=(0x1f000 ~ 0x1f400) nr_scanned=1023 nr_taken=16
      kcompactd0-41      [000] .....   513.347263: mm_compaction_isolate_freepages: range=(0x1ec00 ~ 0x1f000) nr_scanned=1023 nr_taken=23
      kcompactd0-41      [000] .....   513.347298: mm_compaction_isolate_freepages: range=(0x1e800 ~ 0x1ec00) nr_scanned=1024 nr_taken=15
      kcompactd0-41      [000] .....   513.347339: mm_compaction_isolate_freepages: range=(0x1e400 ~ 0x1e800) nr_scanned=1023 nr_taken=22
      kcompactd0-41      [000] .....   513.347374: mm_compaction_isolate_freepages: range=(0x1e000 ~ 0x1e400) nr_scanned=1024 nr_taken=20
      kcompactd0-41      [000] .....   513.347405: mm_compaction_isolate_freepages: range=(0x1dc00 ~ 0x1e000) nr_scanned=1024 nr_taken=16
      kcompactd0-41      [000] .....   513.347439: mm_compaction_isolate_freepages: range=(0x1d800 ~ 0x1dc00) nr_scanned=1023 nr_taken=18
      kcompactd0-41      [000] .....   513.347475: mm_compaction_isolate_freepages: range=(0x1d400 ~ 0x1d800) nr_scanned=1024 nr_taken=18
      kcompactd0-41      [000] .....   513.347514: mm_compaction_isolate_freepages: range=(0x1d000 ~ 0x1d400) nr_scanned=1023 nr_taken=22
      kcompactd0-41      [000] .....   513.347557: mm_compaction_isolate_freepages: range=(0x1cc00 ~ 0x1d000) nr_scanned=1023 nr_taken=29
      kcompactd0-41      [000] .....   513.347592: mm_compaction_isolate_freepages: range=(0x1c800 ~ 0x1cc00) nr_scanned=1022 nr_taken=21
      kcompactd0-41      [000] .....   513.347635: mm_compaction_isolate_freepages: range=(0x1c000 ~ 0x1c400) nr_scanned=1014 nr_taken=39
      kcompactd0-41      [000] .....   513.347672: mm_compaction_isolate_freepages: range=(0x1bc00 ~ 0x1c000) nr_scanned=1023 nr_taken=23
      kcompactd0-41      [000] .....   513.347716: mm_compaction_isolate_freepages: range=(0x1b800 ~ 0x1bc00) nr_scanned=1024 nr_taken=32
      kcompactd0-41      [000] .....   513.347758: mm_compaction_isolate_freepages: range=(0x1b400 ~ 0x1b800) nr_scanned=1024 nr_taken=24
      kcompactd0-41      [000] .....   513.347796: mm_compaction_isolate_freepages: range=(0x1b000 ~ 0x1b400) nr_scanned=1020 nr_taken=31
      kcompactd0-41      [000] .....   513.347833: mm_compaction_isolate_freepages: range=(0x1ac00 ~ 0x1b000) nr_scanned=1024 nr_taken=15
      kcompactd0-41      [000] .....   513.347865: mm_compaction_isolate_freepages: range=(0x1a800 ~ 0x1ac00) nr_scanned=1023 nr_taken=19
      kcompactd0-41      [000] .....   513.347899: mm_compaction_isolate_freepages: range=(0x1a400 ~ 0x1a800) nr_scanned=1024 nr_taken=14
      kcompactd0-41      [000] .....   513.347939: mm_compaction_isolate_freepages: range=(0x1a000 ~ 0x1a400) nr_scanned=1022 nr_taken=26
      kcompactd0-41      [000] .....   513.347983: mm_compaction_isolate_freepages: range=(0x19c00 ~ 0x1a000) nr_scanned=1016 nr_taken=44
      kcompactd0-41      [000] .....   513.348024: mm_compaction_isolate_freepages: range=(0x19800 ~ 0x19c00) nr_scanned=1023 nr_taken=26
      kcompactd0-41      [000] .....   513.348062: mm_compaction_isolate_freepages: range=(0x19400 ~ 0x19800) nr_scanned=1022 nr_taken=31
      kcompactd0-41      [000] .....   513.348099: mm_compaction_isolate_freepages: range=(0x19000 ~ 0x19400) nr_scanned=1022 nr_taken=27
      kcompactd0-41      [000] .....   513.348165: mm_compaction_isolate_freepages: range=(0x18c00 ~ 0x19000) nr_scanned=1019 nr_taken=44
      kcompactd0-41      [000] .....   513.348205: mm_compaction_isolate_freepages: range=(0x18800 ~ 0x18c00) nr_scanned=1020 nr_taken=28
      kcompactd0-41      [000] .....   513.348246: mm_compaction_isolate_freepages: range=(0x18400 ~ 0x18800) nr_scanned=1022 nr_taken=32
      kcompactd0-41      [000] .....   513.348289: mm_compaction_isolate_freepages: range=(0x18000 ~ 0x18400) nr_scanned=1017 nr_taken=29
      kcompactd0-41      [000] .....   513.348333: mm_compaction_isolate_freepages: range=(0x17c00 ~ 0x18000) nr_scanned=1020 nr_taken=29
      kcompactd0-41      [000] .....   513.348365: mm_compaction_isolate_freepages: range=(0x17800 ~ 0x17c00) nr_scanned=1017 nr_taken=15
      kcompactd0-41      [000] .....   513.348383: mm_compaction_isolate_freepages: range=(0x17400 ~ 0x17800) nr_scanned=1024 nr_taken=0
      kcompactd0-41      [000] .....   513.348405: mm_compaction_isolate_freepages: range=(0x17000 ~ 0x17400) nr_scanned=512 nr_taken=9
      kcompactd0-41      [000] .....   513.348449: mm_compaction_isolate_freepages: range=(0x16c00 ~ 0x17000) nr_scanned=1022 nr_taken=34
      kcompactd0-41      [000] .....   513.348543: mm_compaction_isolate_freepages: range=(0x16800 ~ 0x16c00) nr_scanned=1022 nr_taken=30
      kcompactd0-41      [000] .....   513.348588: mm_compaction_isolate_freepages: range=(0x16400 ~ 0x16800) nr_scanned=1021 nr_taken=31
      kcompactd0-41      [000] .....   513.348621: mm_compaction_isolate_freepages: range=(0x16000 ~ 0x163c2) nr_scanned=962 nr_taken=20
      kcompactd0-41      [000] .....   513.368115: mm_compaction_migratepages: nr_migrated=934 nr_failed=0
      kcompactd0-41      [000] .....   513.368125: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.368204: mm_compaction_isolate_migratepages: range=(0x10000 ~ 0x10400) nr_scanned=951 nr_taken=1
      kcompactd0-41      [000] .....   513.368217: mm_compaction_migratepages: nr_migrated=1 nr_failed=0
      kcompactd0-41      [000] .....   513.368219: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.368246: mm_compaction_isolate_migratepages: range=(0x10400 ~ 0x10426) nr_scanned=34 nr_taken=32
      kcompactd0-41      [000] .....   513.368255: mm_compaction_isolate_freepages: range=(0x163c2 ~ 0x16400) nr_scanned=62 nr_taken=2
      kcompactd0-41      [000] .....   513.368302: mm_compaction_isolate_freepages: range=(0x15800 ~ 0x15c00) nr_scanned=1023 nr_taken=22
      kcompactd0-41      [000] .....   513.368321: mm_compaction_isolate_freepages: range=(0x15400 ~ 0x1555c) nr_scanned=348 nr_taken=8
      kcompactd0-41      [000] .....   513.369002: mm_compaction_migratepages: nr_migrated=32 nr_failed=0
      kcompactd0-41      [000] .....   513.369010: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue
      kcompactd0-41      [000] .....   513.369833: mm_compaction_isolate_migratepages: range=(0x10426 ~ 0x10800) nr_scanned=804 nr_taken=739
      kcompactd0-41      [000] .....   513.369923: mm_compaction_isolate_freepages: range=(0x1555c ~ 0x15800) nr_scanned=676 nr_taken=17
      kcompactd0-41      [000] .....   513.369975: mm_compaction_isolate_freepages: range=(0x15000 ~ 0x15400) nr_scanned=1022 nr_taken=27
      kcompactd0-41      [000] .....   513.370033: mm_compaction_isolate_freepages: range=(0x14c00 ~ 0x15000) nr_scanned=1019 nr_taken=35
      kcompactd0-41      [000] .....   513.370138: mm_compaction_isolate_freepages: range=(0x14800 ~ 0x14c00) nr_scanned=1023 nr_taken=29
      kcompactd0-41      [000] .....   513.370195: mm_compaction_isolate_freepages: range=(0x14400 ~ 0x14800) nr_scanned=1021 nr_taken=40
      kcompactd0-41      [000] .....   513.370252: mm_compaction_isolate_freepages: range=(0x14000 ~ 0x14400) nr_scanned=1021 nr_taken=38
      kcompactd0-41      [000] .....   513.370299: mm_compaction_isolate_freepages: range=(0x13c00 ~ 0x14000) nr_scanned=1023 nr_taken=29
      kcompactd0-41      [000] .....   513.370394: mm_compaction_isolate_freepages: range=(0x13800 ~ 0x13c00) nr_scanned=1022 nr_taken=23
      kcompactd0-41      [000] .....   513.370445: mm_compaction_isolate_freepages: range=(0x13400 ~ 0x13800) nr_scanned=1022 nr_taken=24
      kcompactd0-41      [000] .....   513.370482: mm_compaction_isolate_freepages: range=(0x13000 ~ 0x13400) nr_scanned=1023 nr_taken=14
      kcompactd0-41      [000] .....   513.370525: mm_compaction_isolate_freepages: range=(0x12c00 ~ 0x13000) nr_scanned=1012 nr_taken=21
      kcompactd0-41      [000] .....   513.370977: mm_compaction_isolate_freepages: range=(0x12800 ~ 0x12c00) nr_scanned=1013 nr_taken=49
      kcompactd0-41      [000] .....   513.371026: mm_compaction_isolate_freepages: range=(0x12400 ~ 0x12800) nr_scanned=1017 nr_taken=41
      kcompactd0-41      [000] .....   513.371069: mm_compaction_isolate_freepages: range=(0x12000 ~ 0x12400) nr_scanned=1019 nr_taken=34
      kcompactd0-41      [000] .....   513.371121: mm_compaction_isolate_freepages: range=(0x11c00 ~ 0x12000) nr_scanned=1011 nr_taken=51
      kcompactd0-41      [000] .....   513.371166: mm_compaction_isolate_freepages: range=(0x11800 ~ 0x11c00) nr_scanned=1022 nr_taken=43
      kcompactd0-41      [000] .....   513.371216: mm_compaction_isolate_freepages: range=(0x11400 ~ 0x11800) nr_scanned=1017 nr_taken=46
      kcompactd0-41      [000] .....   513.371270: mm_compaction_isolate_freepages: range=(0x11000 ~ 0x11400) nr_scanned=1010 nr_taken=71
      kcompactd0-41      [000] .....   513.371305: mm_compaction_isolate_freepages: range=(0x10c00 ~ 0x10dc0) nr_scanned=406 nr_taken=111
      kcompactd0-41      [000] .....   513.384887: mm_compaction_migratepages: nr_migrated=739 nr_failed=0
      kcompactd0-41      [000] .....   513.384896: mm_compaction_finished: node=0 zone=Normal   order=-1 ret=continue

Linux内存管理（78）：kcompactd详解
私房菜
09-20 2425
伙伴系统以页面为单位来管理内存，内存碎片也是基于页面的，即由大量离散且不连续的页面组成的。从内核角度来看，出现内存碎片不是好事情，有些情况下物理设备需要大段的连续的物理内存，如果内核无法满足，则会发生内核错误。内存规整就是为了解决内核碎片化而出现的一个功能。内核中去碎片化的基本原理是按照页面的可移动性将页面分组。迁移内核本身使用的物理内存的实现难度和复杂度都很大，因此目前的内存不迁移内核本身使用的物理页面。
Linux内存管理（79）：直接内存规整详解
私房菜
09-21 1316
在前一篇博文手动规整；kcompactd 内核线程规整；直接内存规整；前两种方式已经与Linux 内核参数：compaction一文和kcompactd详解一文剖析过，本文将继续剖析第三种规整方式——直接内存规整，以及规整处理的核心函数。
Linux内存管理-内存规整
m0_74282605的博客
02-07 706
compact_zone_order调用compact_zone，最主要的就是将参数填入struct compact_control结构体，然后和zone一起作为参数传递给compact_zone。其中compact_pddat->__compact_pgdat->compact_zone，最终的实现和__alloc_pages_direct_compact调用compact_zone一样。struct compact_control数据结构记录了被迁移的页面，以及规整过程中迁移到的页面列表。
kcompactd浅析
kaka__55的博客
10-22 3439
之所以想写这篇文章，是因为一个问题： 如果我使用slab的时候向内核申请了一个不可移动页，但是此时内核没有不可移动页了，只剩下unmovable的页，那么，根据伙伴系统的设计，会从movable页里面取出来一个用于分配（见__rmqueue_fallback函数）,那么，根据内存规整子系统设计的原则，可移动页是最适合做规整的，如果这个slab使用的页面被规整程序移动了，那slab系统不就乱套了吗？此外，书中好像并没有看到说不可移动页是怎么做规整的，那么，规整子系统真的移动了不可移动页吗，如果为真，那这个页是
超详细！Linux内核内存规整详解
内核工匠
11-10 2501
1.前言伙伴系统作为内核最基础的物理页内存分配器，具有高效、实现逻辑简介等优点，其原理页也尽可能降低内存外部碎片产生，但依然无法杜绝碎片问题。外部碎片带来的最大影响就是内存足够，但是却无法满足内存分配需求，如下图所示：内存外部碎片导致实际占用物理页不多，但是已无法申请>=4个页连续内存，理想当中我们希望内存没有外部碎片，如下图所示：内核并未为此目标设计新的内存分配算法（伙伴系统足够简单和高效...
内存整理
weixin_30752699的博客
04-03 438
1.程序内存虚拟内存布局。 2.内存使用状态。 3.Win32平台下，使用内存的方式。 •（1）CRT函数系如malloc/new/free/delete等； •（2）GlobalAlloc/LocalAlloc系列函数； •（3）虚拟内存函数如VirtualAlloc/VirtualFree等； •（4）内存映射文件函数CreateFileMapping/MapViewOfF...
[内核内存] [arm64] 内存规整1---memory-compaction详解
菁的博客
04-25 1668
typora-root-url: 图片 文章目录1.memory-compaction简介2.memory-compaction调用流程3.memory-compaction源码分析3.1内存规整关键数据结构3.2struct zone中与内存规整相关的成员3.3内存规整扫描zone的基本单位pageblock3.4 fragmentation index（碎片指数）3.5__alloc_pages_direct_compact函数3.5.1compaction_deferred函数（内存规整推迟机制）.
Linux内存管理（64）：kswapd详解(2)
私房菜
08-30 1662
在上一篇博文出现内存碎片时的临时唤醒；内存严重短缺时的唤醒；直接页面回收中的唤醒；kswapd 内部启动的schedule；在上一篇博文中，同样也对 kswapd 所涉及的数据结构、初始化过程进行详细的剖析，本文将继续上一篇博文，详细剖析 kswapd 执行函数到页面回收的整个流程。..................
[内核内存] [arm64] 内存回收4---shrink_node函数详解
菁的博客
04-29 3657
文章目录1 shrink_node函数1.1 shrink_node_memcg1.1.1 get_scan_count函数1.1.2 shrink_list函数1.1.2.1 inactive_list_is_low函数1.1.2.2 shrink_active_list函数1.1.2.3 shrink_inactive_list函数1.1.2.3.1页面回收核心函数shrink_page_list匿名页回收流程文件页回收流程1.2 shrink_slab函数 1 shrink_node函数 shrink
linux内存管理笔记(四十二）----内存规整
奇小葩
03-27 4322
伙伴系统是以页面为单位管理内存，内存碎片也是基于页面，即由大量离散且不连续的页面组成。从内核的角度，出现内存碎片不是什么好的事情，例如 有些情况下物理设备需要大量的连续的物理内存，如果内核无法满足，就会发生内核错误 所以内核对于内存碎片化，需要重新规划调整，因此就出现了本章的主题，内存规整技术，它是为了解决内存碎片化而出现的。本章主要是了解如下内容 内存规整的基本原理 如何触发内存规整 内存规整的使用方法 内存碎片的优化方法 1. 内存规整的基本原理 Linux使用的
17 内存规整(memory compaction)
Do one thing at a time, and do well.
07-21 1116
伙伴系统以页为单位来管理内存，内存碎片也是基于页面的，即有大量离散且不连续的页面导致的。从内存角度来看，内存碎片不是好事情，有些情况下物理设备需要大段的连续的物理内存，如果内核无法满足，则会发生内核panic。内存碎片化好比军训中带队行走时间长了，队列乱了，需要重新规整一下，因此本章称为内存规整，一些文献称为内存紧凑，它是为了解决内存碎片化而出现的一个功能。 内核中去碎片化的基本原理是按照页的可移动性将页面分组。迁移内核本身使用的物理内存的实现难度和复杂度都很大，因此目前的内核是不迁移内核...
Linux内存管理（77）：内存规整简介
私房菜
02-13 966
伙伴系统以页面为单位来管理内存，内存碎片也是基于页面的，即由大量离散且不连续的页面组成的。从内核角度来看，出现内存碎片不是好事情，有些情况下物理设备需要大段的连续的物理内存，如果内核无法满足，则会发生内核错误。内存规整就是为了解决内核碎片化而出现的一个功能。内核中去碎片化的基本原理是按照页面的可移动性将页面分组。迁移内核本身使用的物理内存的实现难度和复杂度都很大，因此目前的内存不迁移内核本身使用的物理页面。
Linux内存管理：(九)内存规整
qq_58538265的博客
01-20 1480
文章说明：Linux内核版本：5.0架构：ARM64参考资料及图片来源：《奔跑吧Linux内核》
java堆的内存规整_JVM内存分配策略
weixin_28727975的博客
02-28 535
-------------------------------------------------------------------------------JVM内存分配策略-----------------------------------------------------------------------------------------一:对象内存分配两种方法为对象分配空间的任务等...
运行错误规整：内存篇
xvjixiang的专栏
04-28 709
1、*** glibc detected *** ./cranetest: corrupted double-linked list: 0x08484100 ***
linux内存管理-页面规整
faxiang1230的专栏
06-06 734
页面整理 页面申请失败有两种情况: 1.空闲页不够，触及到回收的阈值 2.申请order > 0的连续页时找不到连续的物理内存
linux内存管理（十三）-内存规整过程分析
jianjian的博客
07-07 1301
现在看看内存规整迁移再分配函数，__alloc_pages_direct_compact，函数在mm/page_alloc.c文件中： /* Try memory compaction for high-order allocations before reclaim */ static struct page * __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, unsigned int alloc_flags, cons
linux内核那些事之内存规整(memory compact)
weixin_42730667的博客
05-09 1901
内存规整是Mel Gormal开发防止内存碎片anti-fragmen pach补丁的第二个部分Avoiding fragmentation with page clustering v27 [LWN.net]，主要用于解决当系统长时间运行之后，造成比较碎化内存时，通过内存规整将处于可以移动MOVE的类型内存，重新进行页迁移 整合出较大连续物理内存: 内存规整机制原因比较简单： 利用类似快慢指针技巧，当需要对一个zone进行内存规整时，使用migrate_pfn和free_pfn两个遍历； m
linux内存规整,LWN 591998: 内存规整（memory compaction）所存在的问题
weixin_35884854的博客
05-01 261
Memory compaction is the process of relocating active pages in memory in order to create larger, physically contiguous regions — memory defragmentation, in other words. It is useful in a number of way...
直接内存规整触发条件
最新发布
02-27
### Direct Memory Compaction Trigger Conditions in Java In Java, direct memory management involves using off-heap memory through classes like `ByteBuffer.allocateDirect()`. The JVM does not automatically compact direct memory as part of standard garbage collection cycles. However, certain conditions can lead to the triggering of direct memory compaction: #### OutOfMemoryError Prevention Through Soft References Soft references serve as a mechanism to prevent `OutOfMemoryError` by acting as a circuit breaker for memory allocation[^1]. When an application uses excessive amounts of direct memory, leading to potential out-of-memory situations, soft references allow the garbage collector to reclaim these resources before throwing such errors. #### Garbage Collection and Direct Memory Management Java’s garbage collector manages heap-based objects but requires specific handling for direct buffers. While regular destructors are unnecessary due to automatic memory cleanup provided by the garbage collector[^2], direct byte buffers require special attention since they reside outside the main heap space. The following scenarios may prompt actions related to direct memory compaction indirectly: - **High Allocation Rate**: If applications allocate large numbers of direct buffers rapidly without freeing them appropriately. - **Low System Resources**: Insufficient system-level memory available might force the operating system or runtime environment to take action against processes consuming too much non-heap memory. ```java import java.nio.ByteBuffer; public class DirectMemoryExample { public static void main(String[] args) throws InterruptedException { int size = 10 * 1024 * 1024; // Allocate 10MB buffer ByteBuffer dbuf = ByteBuffer.allocateDirect(size); Thread.sleep(5000); // Simulate work being done dbuf = null; // Release reference allowing GC to clean up if needed } } ``` When dealing with direct memory allocations, developers should ensure proper resource management practices to minimize fragmentation issues over time. Although explicit triggers for compaction aren’t directly exposed via APIs, maintaining good coding habits helps mitigate problems associated with unmanaged growth of direct memory usage.
评论
成就一亿技术人!
拼手气红包6.0元
还能输入1000个字符
 
红包 添加红包
表情包 插入表情
表情包 代码片
 条评论被折叠 查看
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付：10.00元
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付元
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明：

1.余额是钱包充值的虚拟货币，按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载，可以购买VIP、付费专栏及课程。

余额充值