From: Wu Fengguang Do some sanity checkings on the newly added radix tree code. Signed-off-by: Wu Fengguang Signed-off-by: Andrew Morton --- mm/readahead.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff -puN mm/readahead.c~readahead-debug-radix-tree-new-functions mm/readahead.c --- devel/mm/readahead.c~readahead-debug-radix-tree-new-functions 2006-06-09 01:22:55.000000000 -0700 +++ devel-akpm/mm/readahead.c 2006-06-09 01:22:55.000000000 -0700 @@ -75,6 +75,8 @@ enum ra_class { RA_CLASS_COUNT }; +#define DEBUG_READAHEAD_RADIXTREE + /* Read-ahead events to be accounted. */ enum ra_event { RA_EVENT_CACHE_MISS, /* read cache misses */ @@ -1303,6 +1305,16 @@ static pgoff_t find_segtail(struct addre cond_resched(); read_lock_irq(&mapping->tree_lock); ra_index = radix_tree_scan_hole(&mapping->page_tree, index, max_scan); +#ifdef DEBUG_READAHEAD_RADIXTREE + BUG_ON(!__probe_page(mapping, index)); + WARN_ON(ra_index < index); + if (ra_index != index && !__probe_page(mapping, ra_index - 1)) + printk(KERN_ERR "radix_tree_scan_hole(index=%lu ra_index=%lu " + "max_scan=%lu nrpages=%lu) fooled!\n", + index, ra_index, max_scan, mapping->nrpages); + if (ra_index != ~0UL && ra_index - index < max_scan) + WARN_ON(__probe_page(mapping, ra_index)); +#endif read_unlock_irq(&mapping->tree_lock); if (ra_index <= index + max_scan) @@ -1386,6 +1398,13 @@ static unsigned long query_page_cache_se read_lock_irq(&mapping->tree_lock); index = radix_tree_scan_hole_backward(&mapping->page_tree, offset - 1, ra_max); +#ifdef DEBUG_READAHEAD_RADIXTREE + WARN_ON(index > offset - 1); + if (index != offset - 1) + WARN_ON(!__probe_page(mapping, index + 1)); + if (index && offset - 1 - index < ra_max) + WARN_ON(__probe_page(mapping, index)); +#endif *remain = (offset - 1) - index; _