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| author | NeilBrown <neilb@suse.com> | 2017-03-15 14:05:14 +1100 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-03-22 19:18:43 -0700 |
| commit | 210f7cdcf088c304ee0533ffd33d6f71a8821862 (patch) | |
| tree | b039d920dc1bef971d419a06cee4c7544fec4afd /include/linux/percpu-refcount.h | |
| parent | 55cc39f345256af241deb6152ff5c06bedd10f11 (diff) | |
| download | linux-210f7cdcf088c304ee0533ffd33d6f71a8821862.tar.gz | |
percpu-refcount: support synchronous switch to atomic mode.
percpu_ref_switch_to_atomic_sync() schedules the switch to atomic mode, then
waits for it to complete.
Also export percpu_ref_switch_to_* so they can be used from modules.
This will be used in md/raid to count the number of pending write
requests to an array.
We occasionally need to check if the count is zero, but most often
we don't care.
We always want updates to the counter to be fast, as in some cases
we count every 4K page.
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'include/linux/percpu-refcount.h')
| -rw-r--r-- | include/linux/percpu-refcount.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 3a481a49546e..c13dceb87b60 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -99,6 +99,7 @@ int __must_check percpu_ref_init(struct percpu_ref *ref, void percpu_ref_exit(struct percpu_ref *ref); void percpu_ref_switch_to_atomic(struct percpu_ref *ref, percpu_ref_func_t *confirm_switch); +void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref); void percpu_ref_switch_to_percpu(struct percpu_ref *ref); void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); |