taskqueue_drain_timeout() fails to detect that the task restarted the timeout
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share/man/man9/taskqueue.9 | ||
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227 | s/Else/Otherwise,' |
I think that this variant of the subr_taskqueue_enqueue_timeout is fine in isolation, i.e. if we ignore the callers.
Did you inspected all callers of the function in the head ? In fact, r306320 is what I mean when we discussed the issue elsewere, and I thnk that despite this change, all callers should be fixed to do the similar treatment to the 'stopped' flag as the mentioned revision.
@kib
Did you inspected all callers of the function in the head ?
There is currently only one place in the kernel where the return value of this function is checked and that is:
sys/fs/autofs/autofs.c: error = taskqueue_enqueue_timeout(taskqueue_thread, sys/fs/autofs/autofs.c- &ar->ar_task, autofs_timeout * hz); sys/fs/autofs/autofs.c- if (error != 0) { sys/fs/autofs/autofs.c: AUTOFS_WARN("taskqueue_enqueue_timeout() failed " sys/fs/autofs/autofs.c- "with error %d", error); sys/fs/autofs/autofs.c- }
From what I can see, this patch will not cause a problem, because the place where the task is residing is a new allocated memory block, so taskqueue_enqueue_timeout() will always return zero.
FYI: r306320 doesn't fully fix the problem. We also need the reliable taskqueue drain.
Ok.
trasz, note that return value from the taskqueue_enqueue_timeout is not an error now, and not quite an error after the patch in this revision is applied.
@kib
Do you think the setting of the DT_DRAIN_IN_PROGRESS flag should be in its own function?
--HPS
Do you mean, should you create two helper inline functions to set and clear the flag ? I do not think it is important since right now the functions are single-use.
Yes, I was just wondering if that would be useful in the case where you want to do flush instead of drain, like inserting a barrier. Right now there is no need for such a function.
I'll wait for @trasz to respond and then I'll push.
Thank you!
head/share/man/man9/taskqueue.9 | ||
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226 ↗ | (On Diff #20805) | Passive -> active: This function returns -1 if the queue is being drained. Otherwise, the number of pending calls is returned. |