lkml.org 
[lkml]   [2019]   [Apr]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 08/16] locking/rwsem: Make rwsem_spin_on_owner() return owner state
On Sat, Apr 13, 2019 at 01:22:51PM -0400, Waiman Long wrote:
> This patch modifies rwsem_spin_on_owner() to return four possible
> values to better reflect the state of lock holder which enables us to
> make a better decision of what to do next.
>
> In the special case that there is no active lock and the handoff bit
> is set, optimistic spinning has to be stopped.
>
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
> kernel/locking/rwsem.c | 45 +++++++++++++++++++++++++++++++++++-------
> 1 file changed, 38 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
> index aaab546a890d..2d6850c3e77b 100644
> --- a/kernel/locking/rwsem.c
> +++ b/kernel/locking/rwsem.c
> @@ -156,6 +156,11 @@ static inline bool is_rwsem_owner_spinnable(struct task_struct *owner)
> return !((unsigned long)owner & RWSEM_ANONYMOUSLY_OWNED);
> }
>
> +static inline bool is_rwsem_owner_reader(struct task_struct *owner)
> +{
> + return (unsigned long)owner & RWSEM_READER_OWNED;
> +}

Move this and the surrounding helpers into the RWSEM_SPIN_ON_OWNER
block, it is only used there and that way all the code is together.

\
 
 \ /
  Last update: 2019-04-17 11:01    [W:0.391 / U:1.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site