Re: Thread model (was: Ext2 superblock fault)

[Michal Suchanek]

On 19/03/2008, Samuel Thibault <samuel.thibault@ens-lyon.org> wrote:

>
> Yes, that's what I meant actually: the diskfs_sync_everything() function
>  is able to trigger a lot of thread creations.
>
>  A way to have things work correctly would be by marking threads with a
>  "level", i.e. diskfs_sync_everything runs at level 0, threads that it
>  generates run at level 1, and threads that process their page faults run
>  at level 2, etc.  Then we just need to limit the number of threads for a
>  given level.  That should always permit termination of requests, while
>  still limiting the number of thread to a constant times the maximum
>  nesting of page faults.
>
How would you increase the level?

Would that mean that some initial process is level 1, login level 2, a
user process started from top level shell level 3, from window manager
level n >> 3?

Or does the level increase only when the thread goes through some page
fault port? How many levels can result from this?

Thanks

Michal