diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-11-23 09:04:05 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-11-23 09:04:05 +0100 |
| commit | 92907cbbef8625bb3998d1eb385fc88f23c97a3f (patch) | |
| tree | 15626ff9287e37c3cb81c7286d6db5a7fd77c854 /fs/btrfs/locking.c | |
| parent | 15fbfccfe92c62ae8d1ecc647c44157ed01ac02e (diff) | |
| parent | 1ec218373b8ebda821aec00bb156a9c94fad9cd4 (diff) | |
Merge tag 'v4.4-rc2' into drm-intel-next-queued
Linux 4.4-rc2
Backmerge to get at
commit 1b0e3a049efe471c399674fd954500ce97438d30
Author: Imre Deak <imre.deak@intel.com>
Date: Thu Nov 5 23:04:11 2015 +0200
drm/i915/skl: disable display side power well support for now
so that we can proplery re-eanble skl power wells in -next.
Conflicts are just adjacent lines changed, except for intel_fbdev.c
where we need to interleave the changs. Nothing nefarious.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'fs/btrfs/locking.c')
| -rw-r--r-- | fs/btrfs/locking.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index d7e6baf1b205..8077461fc56a 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -79,6 +79,9 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw) write_lock(&eb->lock); WARN_ON(atomic_read(&eb->spinning_writers)); atomic_inc(&eb->spinning_writers); + /* + * atomic_dec_and_test implies a barrier for waitqueue_active + */ if (atomic_dec_and_test(&eb->blocking_writers) && waitqueue_active(&eb->write_lock_wq)) wake_up(&eb->write_lock_wq); @@ -86,6 +89,9 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw) BUG_ON(atomic_read(&eb->blocking_readers) == 0); read_lock(&eb->lock); atomic_inc(&eb->spinning_readers); + /* + * atomic_dec_and_test implies a barrier for waitqueue_active + */ if (atomic_dec_and_test(&eb->blocking_readers) && waitqueue_active(&eb->read_lock_wq)) wake_up(&eb->read_lock_wq); @@ -229,6 +235,9 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb) } btrfs_assert_tree_read_locked(eb); WARN_ON(atomic_read(&eb->blocking_readers) == 0); + /* + * atomic_dec_and_test implies a barrier for waitqueue_active + */ if (atomic_dec_and_test(&eb->blocking_readers) && waitqueue_active(&eb->read_lock_wq)) wake_up(&eb->read_lock_wq); @@ -280,6 +289,9 @@ void btrfs_tree_unlock(struct extent_buffer *eb) if (blockers) { WARN_ON(atomic_read(&eb->spinning_writers)); atomic_dec(&eb->blocking_writers); + /* + * Make sure counter is updated before we wake up waiters. + */ smp_mb(); if (waitqueue_active(&eb->write_lock_wq)) wake_up(&eb->write_lock_wq); |