[PATCH 7/7] nvme: Send change uevent when AEN completes

[Guan Junxiong]

Hi, Keith

Any update about this patch?  We are keen on planning to use this kind of
feature to handle some events of controller/subsystem with multipath-tools.

Thanks

Best wishes
Guan Junxiong

On 2017/7/17 23:22, Keith Busch wrote:
> On Sat, Jul 15, 2017 at 10:42:18AM +0200, Christoph Hellwig wrote:
>>
>> Take the Changed Namespace List log page for example.
>>
>> We get an AER, and then both schedule a log page read in the kernel
>> (as we should, patch pending) and send the uevent.  As soon as the
>> read the log page in the kernel to clear the log page we get another
>> event due to another namespace change, but not userspace manages to
>> read the log page before the kernel acts on the next AER, so the
>> kernel won't see the changes.
>>
>> And yes, this is probably a little constructed, but we'll get more
>> log pages with similar semantics, so I am worried a bit about this.
> 
> That event needs to already be handled by the driver without relying
> on the Changed Namespace List log, like when the list exceeds the log
> size. But okay, I see the concern in general if reading a log page may
> change the results.
> 
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