Re: [RFC PATCH 02/21] list: Remove hlist_nulls_unhashed_lockless()

[Greg KH]

On Tue, Mar 24, 2020 at 03:36:24PM +0000, Will Deacon wrote:
> Commit 02b99b38f3d9 ("rcu: Add a hlist_nulls_unhashed_lockless() function")
> introduced the (as yet unused) hlist_nulls_unhashed_lockless() function
> to avoid KCSAN reports when an RCU reader checks the 'hashed' status
> of an 'hlist_nulls' concurrently undergoing modification.
> 
> Remove the unused function and add a READ_ONCE() to hlist_nulls_unhashed(),
> just like we do already for hlist_nulls_empty().
> 
> Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> ---
>  include/linux/list_nulls.h | 14 --------------
>  1 file changed, 14 deletions(-)

Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>