Re: Deferred freeing of kauth_cred_ts

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

Hello,

Elad Efrat <elad%NetBSD.org@localhost> wrote:
> One thing that prevents us from attaching credentials to sockets is an
> issue where these might be freed from interrupt context.
> 
> What I have in mind is being able to tell when we can sleep or not,
> and if not, add the credentials to a queue that an independent thread
> will take care of freeing.
> 
> If this is sensible, my first step will be extracting the guts of
> assert_sleepable() to is_sleepable() so we don't always trip a panic()
> if we can't sleep.

Using is_sleepable() for decision making would be wrong.  As Adam mentioned,
garbage collecting in a separate thread can be a solution, however it is not
desirable.  It can be deferred to some transition point in kernel, though.

The question is - why freeing is performed from interrupt context?

-- 
Mindaugas