Hello,
Miklos Szeredi wrote:

quoted text
>> * Higher overhead when poll/select finishes.  Either all outstanding

>>   requests need to be cancelled using INTERRUPT whenever poll/select

>>   returns or kernel needs to keep persistent list of outstanding polls

>>   so that later poll/select can reuse them.  The problem here is that

>>   kernel doesn't know when or whether they'll be re-used.  We can put

>>   in LRU-based heuristics but it's getting too complex.

>

> Why not just link the outstanding poll requests into a list anchored

> in 'fuse_file'?  Easy to reuse, don't care about cancellation.

Ah, that's the right place.
>> Overall, I think being lazy about cancellation and let userland notify

quoted text
>> asynchronously would be better performance and simplicity wise.  What

>> do you think?

>

> Lazy cancellation (no cancellation, esentially) sounds good.  But that

> works fine with the simplified protocol.

>

> Think of it this way, this is what a poll event would look like with

> your scheme:

>

> 1) -> POLL-notification

> 2) <- POLL-req

> 3) -> POLL-reply (revents)

>

> Notice, how 1) and 2) don't carry _any_ information (the notification

> can be spurious, the events in the POLL request is just repeated from

> the original request).  All the info is in 3), so I really don't see

> any reason why the above would be better than just omitting the first

> two steps.

Alrighty then.  I'll convert it.
Thanks.
--

tejun

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