diff options
| author | Chris Wilson <[email protected]> | 2016-08-29 19:16:13 +0100 |
|---|---|---|
| committer | Sumit Semwal <[email protected]> | 2016-09-13 20:09:49 +0530 |
| commit | ecebca79f6976ddaddfd054d699272515869ea28 (patch) | |
| tree | 2afcc2ba082109305f86932c6c3751870fe6804a | |
| parent | f6ce410a59a48aff47bb7e18ab40497e4e80d275 (diff) | |
dma-buf/sync-file: Avoid enable fence signaling if poll(.timeout=0)
If we being polled with a timeout of zero, a nonblocking busy query,
we don't need to install any fence callbacks as we will not be waiting.
As we only install the callback once, the overhead comes from the atomic
bit test that also causes serialisation between threads.
Signed-off-by: Chris Wilson <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: Gustavo Padovan <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Reviewed-by: Gustavo Padovan <[email protected]>
Signed-off-by: Sumit Semwal <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
| -rw-r--r-- | drivers/dma-buf/sync_file.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c index 486d29c1a830..abb5fdab75fd 100644 --- a/drivers/dma-buf/sync_file.c +++ b/drivers/dma-buf/sync_file.c @@ -306,7 +306,8 @@ static unsigned int sync_file_poll(struct file *file, poll_table *wait) poll_wait(file, &sync_file->wq, wait); - if (!test_and_set_bit(POLL_ENABLED, &sync_file->fence->flags)) { + if (!poll_does_not_wait(wait) && + !test_and_set_bit(POLL_ENABLED, &sync_file->fence->flags)) { if (fence_add_callback(sync_file->fence, &sync_file->cb, fence_check_cb_func) < 0) wake_up_all(&sync_file->wq); |