diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-02 21:08:07 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-02 21:08:07 -0400 |
| commit | d52bd54db8be8999df6df5a776f38c4f8b5e9cea (patch) | |
| tree | 0d8f436e959bb975c002ddf12ea1bdc9adadd04f /kernel/task_work.c | |
| parent | 8cbdd85bda499d028b8f128191f392d701e8e41d (diff) | |
| parent | 3bd080e4d8f2351ee3e143f0ec9307cc95ae6639 (diff) | |
Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:
- the rest of ocfs2
- various hotfixes, mainly MM
- quite a bit of misc stuff - drivers, fork, exec, signals, etc.
- printk updates
- firmware
- checkpatch
- nilfs2
- more kexec stuff than usual
- rapidio updates
- w1 things
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
ipc: delete "nr_ipc_ns"
kcov: allow more fine-grained coverage instrumentation
init/Kconfig: add clarification for out-of-tree modules
config: add android config fragments
init/Kconfig: ban CONFIG_LOCALVERSION_AUTO with allmodconfig
relay: add global mode support for buffer-only channels
init: allow blacklisting of module_init functions
w1:omap_hdq: fix regression
w1: add helper macro module_w1_family
w1: remove need for ida and use PLATFORM_DEVID_AUTO
rapidio/switches: add driver for IDT gen3 switches
powerpc/fsl_rio: apply changes for RIO spec rev 3
rapidio: modify for rev.3 specification changes
rapidio: change inbound window size type to u64
rapidio/idt_gen2: fix locking warning
rapidio: fix error handling in mbox request/release functions
rapidio/tsi721_dma: advance queue processing from transfer submit call
rapidio/tsi721: add messaging mbox selector parameter
rapidio/tsi721: add PCIe MRRS override parameter
rapidio/tsi721_dma: add channel mask and queue size parameters
...
Diffstat (limited to 'kernel/task_work.c')
| -rw-r--r-- | kernel/task_work.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c index 6ab4842b00e8..d513051fcca2 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -29,7 +29,7 @@ task_work_add(struct task_struct *task, struct callback_head *work, bool notify) struct callback_head *head; do { - head = ACCESS_ONCE(task->task_works); + head = READ_ONCE(task->task_works); if (unlikely(head == &work_exited)) return -ESRCH; work->next = head; @@ -57,6 +57,9 @@ task_work_cancel(struct task_struct *task, task_work_func_t func) struct callback_head **pprev = &task->task_works; struct callback_head *work; unsigned long flags; + + if (likely(!task->task_works)) + return NULL; /* * If cmpxchg() fails we continue without updating pprev. * Either we raced with task_work_add() which added the @@ -64,8 +67,7 @@ task_work_cancel(struct task_struct *task, task_work_func_t func) * we raced with task_work_run(), *pprev == NULL/exited. */ raw_spin_lock_irqsave(&task->pi_lock, flags); - while ((work = ACCESS_ONCE(*pprev))) { - smp_read_barrier_depends(); + while ((work = lockless_dereference(*pprev))) { if (work->func != func) pprev = &work->next; else if (cmpxchg(pprev, work, work->next) == work) @@ -95,7 +97,7 @@ void task_work_run(void) * work_exited unless the list is empty. */ do { - work = ACCESS_ONCE(task->task_works); + work = READ_ONCE(task->task_works); head = !work && (task->flags & PF_EXITING) ? &work_exited : NULL; } while (cmpxchg(&task->task_works, work, head) != work); |