Do some sanity checkings on the newly added radix tree code. Signed-off-by: Wu Fengguang --- mm/readahead.c | 24 ++++++++++++++++++++++++ 1 files changed, 24 insertions(+) --- linux-2.6.17-rc4-mm3.orig/mm/readahead.c +++ linux-2.6.17-rc4-mm3/mm/readahead.c @@ -63,6 +63,8 @@ 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 */ @@ -1315,6 +1317,16 @@ 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(!__find_page(mapping, index)); + WARN_ON(ra_index < index); + if (ra_index != index && !__find_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(__find_page(mapping, ra_index)); +#endif read_unlock_irq(&mapping->tree_lock); if (ra_index <= index + max_scan) @@ -1407,6 +1419,13 @@ static unsigned long query_page_cache_se read_lock_irq(&mapping->tree_lock); index = radix_tree_scan_hole_backward(&mapping->page_tree, offset, ra_max); +#ifdef DEBUG_READAHEAD_RADIXTREE + WARN_ON(index > offset); + if (index != offset) + WARN_ON(!__find_page(mapping, index + 1)); + if (index && offset - index < ra_max) + WARN_ON(__find_page(mapping, index)); +#endif read_unlock_irq(&mapping->tree_lock); *remain = offset - index; @@ -1442,6 +1461,11 @@ static unsigned long query_page_cache_se struct radix_tree_node *node; node = radix_tree_cache_lookup_parent(&mapping->page_tree, &cache, offset - count, 1); +#ifdef DEBUG_READAHEAD_RADIXTREE + if (node != radix_tree_lookup_parent(&mapping->page_tree, + offset - count, 1)) + BUG(); +#endif if (!node) break; } --