Re: [PATCH] btrfs: Relax memory barrier in btrfs_tree_unlock

2018-03-07 Thread David Sterba
On Wed, Feb 14, 2018 at 02:37:26PM +0200, Nikolay Borisov wrote: > When performing an unlock on an extent buffer we'd like to order the > decrement of extent_buffer::blocking_writers with waking up any > waiters. In such situations it's sufficient to use smp_mb__after_atomic > rather than the

Re: [PATCH] btrfs: Relax memory barrier in btrfs_tree_unlock

2018-02-24 Thread Nikolay Borisov
On 24.02.2018 02:14, David Sterba wrote: > On Wed, Feb 14, 2018 at 02:37:26PM +0200, Nikolay Borisov wrote: >> When performing an unlock on an extent buffer we'd like to order the >> decrement of extent_buffer::blocking_writers with waking up any >> waiters. In such situations it's sufficient to

Re: [PATCH] btrfs: Relax memory barrier in btrfs_tree_unlock

2018-02-23 Thread David Sterba
On Wed, Feb 14, 2018 at 02:37:26PM +0200, Nikolay Borisov wrote: > When performing an unlock on an extent buffer we'd like to order the > decrement of extent_buffer::blocking_writers with waking up any > waiters. In such situations it's sufficient to use smp_mb__after_atomic > rather than the

[PATCH] btrfs: Relax memory barrier in btrfs_tree_unlock

2018-02-14 Thread Nikolay Borisov
When performing an unlock on an extent buffer we'd like to order the decrement of extent_buffer::blocking_writers with waking up any waiters. In such situations it's sufficient to use smp_mb__after_atomic rather than the heavy smp_mb. On architectures where atomic operations are fully ordered