On Wed 04-10-17 17:20:06, Waiman Long wrote: > Insertion and deletion is relatively cheap and mostly contention > free for dlock-list. Lookup, on the other hand, can be rather costly > because all the lists in a dlock-list will have to be iterated. > > Currently dlock-list insertion is based on the cpu that the task is > running on. So a given object can be inserted into any one of the > lists depending on what the current cpu is. > > This patch provides an alternative way of list selection. The caller > can provide a object context which will be hashed to one of the list > in a dlock-list. The object can then be added into that particular > list. Lookup can be done by iterating elements in the provided list > only instead of all the lists in a dlock-list. > > The new APIs are: > > struct dlock_list_head *dlock_list_hash(struct dlock_list_heads *, void *); > void dlock_list_add(struct dlock_list_node *, struct dlock_list_head *); > > Signed-off-by: Waiman Long <longman@xxxxxxxxxx> OK, this makes sense but do you have any particular user in mind? In particular I'm not sure how big advantage this API brings over an existing one in include/linux/list_bl.h. Sure it's a tradeoff between bitlock / spinlock but is there a user where it matters? Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
