radix_tree_next_hole is implemented as a series of radix_tree_lookup()s. So it can be called locklessly, under rcu_read_lock(). Signed-off-by: Nick Piggin --- Index: linux-2.6/mm/readahead.c =================================================================== --- linux-2.6.orig/mm/readahead.c +++ linux-2.6/mm/readahead.c @@ -382,9 +382,9 @@ ondemand_readahead(struct address_space if (hit_readahead_marker) { pgoff_t start; - read_lock_irq(&mapping->tree_lock); - start = radix_tree_next_hole(&mapping->page_tree, offset, max+1); - read_unlock_irq(&mapping->tree_lock); + rcu_read_lock(); + start = radix_tree_next_hole(&mapping->page_tree, offset,max+1); + rcu_read_unlock(); if (!start || start - offset > max) return 0; -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/