由于有次使用for_each_zone 的函数 无法使用
mm/bootmem.c#0027 这里定义吗 ？
0026 #ifndef CONFIG_NEED_MULTIPLE_NODES 0027 struct pglist_data __refdata contig_page_data = { 0028 .bdata = &bootmem_node_data[0] 0029 }; 0030 EXPORT_SYMBOL(contig_page_data);
mm/bootmem.c#0027 ？
0026 #ifndef CONFIG_NEED_MULTIPLE_NODES 0027 struct pglist_data __refdata contig_page_data; 0028 EXPORT_SYMBOL(contig_page_data); 0029 #endif
直接有个结构体：
0860 extern struct pglist_data contig_page_data;
module 打印
printk( "node_data = *%p* ", &contig_page_data );
printk( "contig_page_data.node_zones[0] = [%s] ",
contig_page_data.node_zones[0].name );
printk( "contig_page_data.node_zones[1] = [%s] ",
contig_page_data.node_zones[1].name );
printk( "contig_page_data.node_zones[2] = [%s] ",
contig_page_data.node_zones[2].name );
if( contig_page_data.node_zones[3].name )
printk( "contig_page_data.node_zones[3] = [%s] ",
contig_page_data.node_zones[3].name );
输出：
node_data = *c18a0580*
contig_page_data.node_zones[0] = [DMA]
contig_page_data.node_zones[1] = [Normal]
contig_page_data.node_zones[2] = [HighMem]
contig_page_data.node_zones[3] = [Movable]
记录，便于观看内核的mm
struct zone { 0330 /* Fields commonly accessed by the page allocator 这个域通常被page allocator 访问*/ 0331 0332 /* zone watermarks, access with *_wmark_pages(zone) macros 使用宏访问*/ 0333 unsigned long watermark[NR_WMARK]; 0334 0335 /* 0336 * When free pages are below this point, additional steps are taken 0337 * when reading the number of free pages to avoid per-cpu counter 0338 * drift allowing watermarks to be breached 0339 */ 0340 unsigned long percpu_drift_mark; 0341 0342 /* 0343 * We don't know if the memory that we're going to allocate will be freeable 0344 * or/and it will be released eventually, so to avoid totally wasting several 0345 * GB of ram we must reserve some of the lower zone memory (otherwise we risk 0346 * to run OOM on the lower zones despite there's tons of freeable ram 0347 * on the higher zones). This array is recalculated at runtime if the 0348 * sysctl_lowmem_reserve_ratio sysctl changes. 0349 */ 0350 unsigned long lowmem_reserve[MAX_NR_ZONES]; 0351 0352 /* 0353 * This is a per-zone reserve of pages that should not be 0354 * considered dirtyable memory. 0355 */ 0356 unsigned long dirty_balance_reserve; 0357 0358 #ifdef CONFIG_NUMA 0359 int node; 0360 /* 0361 * zone reclaim becomes active if more unmapped pages exist. 0362 */ 0363 unsigned long min_unmapped_pages; 0364 unsigned long min_slab_pages; 0365 #endif 0366 struct per_cpu_pageset __percpu *pageset; 0367 /* 0368 * free areas of different sizes 0369 */ 0370 spinlock_t lock; 0371 int all_unreclaimable; /* All pages pinned */ 0372 #ifdef CONFIG_MEMORY_HOTPLUG 0373 /* see spanned/present_pages for more description */ 0374 seqlock_t span_seqlock; 0375 #endif 0376 #ifdef CONFIG_CMA 0377 /* 0378 * CMA needs to increase watermark levels during the allocation 0379 * process to make sure that the system is not starved. 0380 */ 0381 unsigned long min_cma_pages; 0382 #endif 0383 struct free_area free_area[MAX_ORDER]; 0384 0385 #ifndef CONFIG_SPARSEMEM 0386 /* 0387 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 0388 * In SPARSEMEM, this map is stored in struct mem_section 0389 */ 0390 unsigned long *pageblock_flags; 0391 #endif /* CONFIG_SPARSEMEM */ 0392 0393 #ifdef CONFIG_COMPACTION 0394 /* 0395 * On compaction failure, 1<<compact_defer_shift compactions 0396 * are skipped before trying again. The number attempted since 0397 * last failure is tracked with compact_considered. 0398 */ 0399 unsigned int compact_considered; 0400 unsigned int compact_defer_shift; 0401 int compact_order_failed; 0402 #endif 0403 0404 ZONE_PADDING(_pad1_) 0405 0406 /* Fields commonly accessed by the page reclaim scanner */ 0407 spinlock_t lru_lock; 0408 struct lruvec lruvec; 0409 0410 unsigned long pages_scanned; /* since last reclaim */ 0411 unsigned long flags; /* zone flags, see below */ 0412 0413 /* Zone statistics */ 0414 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 0415 0416 /* 0417 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on 0418 * this zone's LRU. Maintained by the pageout code. 0419 */ 0420 unsigned int inactive_ratio; 0421 0422 0423 ZONE_PADDING(_pad2_) 0424 /* Rarely used or read-mostly fields */ 0425 0426 /* 0427 * wait_table -- the array holding the hash table 0428 * wait_table_hash_nr_entries -- the size of the hash table array 0429 * wait_table_bits -- wait_table_size == (1 << wait_table_bits) 0430 * 0431 * The purpose of all these is to keep track of the people 0432 * waiting for a page to become available and make them 0433 * runnable again when possible. The trouble is that this 0434 * consumes a lot of space, especially when so few things 0435 * wait on pages at a given time. So instead of using 0436 * per-page waitqueues, we use a waitqueue hash table. 0437 * 0438 * The bucket discipline is to sleep on the same queue when 0439 * colliding and wake all in that wait queue when removing. 0440 * When something wakes, it must check to be sure its page is 0441 * truly available, a la thundering herd. The cost of a 0442 * collision is great, but given the expected load of the 0443 * table, they should be so rare as to be outweighed by the 0444 * benefits from the saved space. 0445 * 0446 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the 0447 * primary users of these fields, and in mm/page_alloc.c 0448 * free_area_init_core() performs the initialization of them. 0449 */ 0450 wait_queue_head_t * wait_table; 0451 unsigned long wait_table_hash_nr_entries; 0452 unsigned long wait_table_bits; 0453 0454 /* 0455 * Discontig memory support fields. 0456 */ 0457 struct pglist_data *zone_pgdat; 0458 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 0459 unsigned long zone_start_pfn; 0460 0461 /* 0462 * zone_start_pfn, spanned_pages and present_pages are all 0463 * protected by span_seqlock. It is a seqlock because it has 0464 * to be read outside of zone->lock, and it is done in the main 0465 * allocator path. But, it is written quite infrequently. 0466 * 0467 * The lock is declared along with zone->lock because it is 0468 * frequently read in proximity to zone->lock. It's good to 0469 * give them a chance of being in the same cacheline. 0470 */ 0471 unsigned long spanned_pages; /* total size, including holes */ 0472 unsigned long present_pages; /* amount of memory (excluding holes) */ 0473 0474 /* 0475 * rarely used fields: 0476 */ 0477 const char *name; 0478 } ____cacheline_internodealigned_in_smp;
起始帧
zone_start_pfn DMA = 16
zone_start_pfn NORMAL = 4096
zone_start_pfn HIGH = 228350
zone_start_pfn MOVIABLE = 0