scheduling off the waiting list

[Nils Goroll]

Hi Poul-Henning,

thank you for your quick response.

>> So basically there are two different scenarios when hsh_rush is called.
>>
>> * Trigger delivery of an object which just got unbusied
>> * and trigger delivery of more sessions which did not fire in the first round
> 
> The basic point here is that we do not want to unleash 500 waiting sessions
> when the object is unbusied, so we release a few, and when they are done
> they each release a few etc.

Sure, and I think this is a good idea.

I should have mentioned that the reason why I care about this is that in 
HSH_Prepare, memory is allocated on sp->http->ws each time a session fires, so 
when it doesn't get to delivery, we can run out of session memory. And I have a 
dozen coredumps showing the workspace filled up with hashptrs.

The symptoms look very much like those in 
http://varnish.projects.linpro.no/ticket/551, and reports of these symptoms 
might be related to this issue.

> Grace mode helps a lot, if you can use it.

Yes, absolutely.

Nils