diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2020-06-30 17:32:54 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-06-30 12:18:08 -0600 |
| commit | e91b48162332480f5840902268108bb7fb7a44c7 (patch) | |
| tree | c7cf68d7e37016bb5a7dc479d5396fee6f7bc776 /kernel/task_work.c | |
| parent | d60b5fbc1ce8210759b568da49d149b868e7c6d3 (diff) | |
| download | linux-e91b48162332480f5840902268108bb7fb7a44c7.tar.bz2 | |
task_work: teach task_work_add() to do signal_wake_up()
So that the target task will exit the wait_event_interruptible-like
loop and call task_work_run() asap.
The patch turns "bool notify" into 0,TWA_RESUME,TWA_SIGNAL enum, the
new TWA_SIGNAL flag implies signal_wake_up(). However, it needs to
avoid the race with recalc_sigpending(), so the patch also adds the
new JOBCTL_TASK_WORK bit included in JOBCTL_PENDING_MASK.
TODO: once this patch is merged we need to change all current users
of task_work_add(notify = true) to use TWA_RESUME.
Cc: stable@vger.kernel.org # v5.7
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel/task_work.c')
| -rw-r--r-- | kernel/task_work.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c index 825f28259a19..5c0848ca1287 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -25,9 +25,10 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */ * 0 if succeeds or -ESRCH. */ int -task_work_add(struct task_struct *task, struct callback_head *work, bool notify) +task_work_add(struct task_struct *task, struct callback_head *work, int notify) { struct callback_head *head; + unsigned long flags; do { head = READ_ONCE(task->task_works); @@ -36,8 +37,19 @@ task_work_add(struct task_struct *task, struct callback_head *work, bool notify) work->next = head; } while (cmpxchg(&task->task_works, head, work) != head); - if (notify) + switch (notify) { + case TWA_RESUME: set_notify_resume(task); + break; + case TWA_SIGNAL: + if (lock_task_sighand(task, &flags)) { + task->jobctl |= JOBCTL_TASK_WORK; + signal_wake_up(task, 0); + unlock_task_sighand(task, &flags); + } + break; + } + return 0; } |