Re: [patch 00/11] ANNOUNCE: "Syslets", generic asynchronous system call support

[Dmitry Torokhov]

On 2/13/07, Alan <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> > A syslet is executed opportunistically: i.e. the syslet subsystem
> > assumes that the syslet will not block, and it will switch to a
> > cachemiss kernel thread from the scheduler. This means that even a
>
> How is scheduler fairness maintained ? and what is done for resource
> accounting here ?
>
> > that the kernel fills and user-space clears. Waiting is done via the
> > sys_async_wait() system call. Completion can be supressed on a per-atom
>
> They should be selectable as well iff possible.
>
> > Open issues:
>
> Let me add some more
>
>        sys_setuid/gid/etc need to be synchronous only and not occur
> while other async syscalls are running in parallel to meet current kernel
> assumptions.
>
>        sys_exec and other security boundaries must be synchronous only
> and not allow async "spill over" (consider setuid async binary patching)
>
> >  - sys_fork() and sys_async_exec() should be filtered out from the
> >    syscalls that are allowed - first one only makes sense with ptregs,
>
> clone and vfork. async_vfork is a real mindbender actually.
>
> >    second one is a nice kernel recursion thing :) I didnt want to
> >    duplicate the sys_call_table though - maybe others have a better
> >    idea.
>
> What are the semantics of async sys_async_wait and async sys_async ?

Ooooohh. OpenVMS lives forever ;) Me likeee ;)

--
Dmitry
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