On Thu, Nov 01, 2018 at 06:50:03PM +0200, Nikolay Borisov wrote:
>
>
> On 1.11.18 г. 18:44 ч., David Sterba wrote:
> > On Thu, Nov 01, 2018 at 09:00:56AM -0700, Omar Sandoval wrote:
> >>> That was an assumption for the demonstration purposes, the wording was
> >>> confusing sorry.
> >>
> >> Oh, well in that case, that's exactly what kthread_park() is ;) Stop the
> >> thread and make wake_up a noop, and then we don't need to add special
> >> cases everywhere else.
> >
> > The end result is equivalent and should be, I'm now weighing both
> > approaches. Explicit state tracking outside of the thread structures
> > seems more clear and in case we want to query the status, we can't after
> > kthread_stop is called. My current version below.
> >
>
> <snip>
>
> > +static inline void btrfs_wake_up_transaction(struct btrfs_fs_info *fs_info)
> > +{
> > + if (!test_bit(BTRFS_FS_CLOSING_SINGLE, &fs_info->flags)) {
>
> Why do we need a separate flag for a predicate? If we use
> FS_CLOSING_START then waking up becomes a noop from the moment
> close_ctree is called.
Yeah it's not strictly necessary, it's a leftover from when I had a
WARN_ON in the wakeup helpers that triggered too often so another flag
was added just after the threads were stopped.
