On Mon, Sep 2, 2024 at 1:38 AM Kinga Stefaniuk
<kinga.stefaniuk@xxxxxxxxx> wrote:
>
> In mdadm commit 49b69533e8 ("mdmonitor: check if udev has finished
> events processing") mdmonitor has been learnt to wait for udev to finish
> processing, and later in commit 9935cf0f64f3 ("Mdmonitor: Improve udev
> event handling") pooling for MD events on /proc/mdstat file has been
> deprecated because relying on udev events is more reliable and less bug
> prone (we are not competing with udev).
>
> After those changes we are still observing missing mdmonitor events in
> some scenarios, especially SpareEvent is likely to be missed. With this
> patch MD will be able to generate more change uevents and wakeup
> mdmonitor more frequently to give it possibility to notice events.
> MD has md_new_events() functionality to trigger events and with this
> patch this function is extended to generate udev CHANGE uevents. It
> cannot be done directly because this function is called on interrupts
> context, so appropriate workqueue is created. Uevents are less time
> critical, it is safe to use workqueue. It is limited to CHANGE event as
> there is no need to generate other uevents for now.
> With this change, mdmonitor events are less likely to be missed. Our
> internal tests suite confirms that, mdmonitor reliability is (again)
> improved.
> Start using irq methods on all_mddevs_lock, because it can be reached
> by interrupt context.
>
> Signed-off-by: Mateusz Grzonka <mateusz.grzonka@xxxxxxxxx>
> Signed-off-by: Kinga Stefaniuk <kinga.stefaniuk@xxxxxxxxx>
I am seeing new failures from mdadm tests, for example, test 01replace.
Please run these tests and fix the issues.
Thanks,
Song
