On Fri, May 14, 2010 at 10:05:24AM +0800, Cesar Eduardo Barros wrote: > radix_tree_prev_hole() used LONG_MAX to detect underflow; however, > ULONG_MAX is clearly what was intended, both here and by its only user > (count_history_pages at mm/readahead.c). Good catch, thanks! I actually have a more smart radix_tree_prev_hole() that uses ULONG_MAX. Andrew, fortunately this bug has little impact on readahead. Reviewed-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> > Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> > Signed-off-by: Cesar Eduardo Barros <cesarb@xxxxxxxxxx> > --- > lib/radix-tree.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/lib/radix-tree.c b/lib/radix-tree.c > index b69031f..be40980 100644 > --- a/lib/radix-tree.c > +++ b/lib/radix-tree.c > @@ -656,7 +656,7 @@ EXPORT_SYMBOL(radix_tree_next_hole); > * > * Returns: the index of the hole if found, otherwise returns an index > * outside of the set specified (in which case 'index - return >= max_scan' > - * will be true). In rare cases of wrap-around, LONG_MAX will be returned. > + * will be true). In rare cases of wrap-around, ULONG_MAX will be returned. > * > * radix_tree_next_hole may be called under rcu_read_lock. However, like > * radix_tree_gang_lookup, this will not atomically search a snapshot of > @@ -674,7 +674,7 @@ unsigned long radix_tree_prev_hole(struct radix_tree_root *root, > if (!radix_tree_lookup(root, index)) > break; > index--; > - if (index == LONG_MAX) > + if (index == ULONG_MAX) > break; > } > > -- > 1.6.6.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>