diff options
Diffstat (limited to 'mm/vmstat.c')
| -rw-r--r-- | mm/vmstat.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c index b0d08e667ec..d7826af2fb0 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -516,9 +516,26 @@ static void pagetypeinfo_showblockcount_print(struct seq_file *m, continue; page = pfn_to_page(pfn); +#ifdef CONFIG_ARCH_FLATMEM_HAS_HOLES + /* + * Ordinarily, memory holes in flatmem still have a valid + * memmap for the PFN range. However, an architecture for + * embedded systems (e.g. ARM) can free up the memmap backing + * holes to save memory on the assumption the memmap is + * never used. The page_zone linkages are then broken even + * though pfn_valid() returns true. Skip the page if the + * linkages are broken. Even if this test passed, the impact + * is that the counters for the movable type are off but + * fragmentation monitoring is likely meaningless on small + * systems. + */ + if (page_zone(page) != zone) + continue; +#endif mtype = get_pageblock_migratetype(page); - count[mtype]++; + if (mtype < MIGRATE_TYPES) + count[mtype]++; } /* Print counts */ |