(userspace) vfs and xio [CAPS?]

[Dave Leimbach]

Matthew Dillon <dillon at xxxxxxxxxxxxxxxxxxxx> writes:

> :I wonder if it would be possible to get cid's into kqueue notification?
> 
>     I intend to change CAPS over to use file descriptors.
> 

Dropping cid's for FDs?  


>     Actually, first, I intend to rip out struct fileops and replace it with
>     all the wonderful METHOD code we have to support devices and busses.
>     That way we can support a whole lot more then what we have in the current
>     fileops structure.
> 

fileops is the part that determines which VFS operations can be performed on a 
given FD correct?  [Sorry... not much of kernel programmer :)]

> 						-Matt
> 
> :I believe the Portals API even specifies some non-contiguous message
> :passing via some iovec like implementation in it's latest specification.
> :
> :For interested parties.
> :http://www.sandiaportals.org
> :
> :I've used this API extensively in the last 3 years and it's not too shabby :).
> :
> :It's being used as the underlying layer of the Lustre cluster file system as
> :well and is implemented in kernel space, IIRC, in linux on top of a Network
> :Abstraction Layer.
> :
> :Pretty neat stuff.  It was designed with scalability in mind as  you don't 
> :require a socket to address other processes... you just have to find it's 
> :pid and nid [process id and node id] to talk to it.  In other words you don't
> :need file descriptors for sockets to do communication.
> :
> :I wouldn't mind taking a few passes at the CAPS stuff perhaps sometime this 
> :week and see what I come up with.  I am relocating all next week but will
> :hopefully have my stuff back from the moving company within 8 days and would
> :be able to resume.
> :
> :Dave
> 
>     I'll definitely take a look at it.  
> 
>     I'll do the work required to convert fileops to the METHOD interface,
>     would you like the job of making CAPS descriptor-based?

I wouldn't mind giving it a shot.  If real life kicks in and prevents me from 
making progress I'll be sure to scream for help :)  I'd hate to have a personal
stall kill a milestone date.

I may require clarification of what exactly your vision is for this.  For
example is the caps cid stuff just going to disappear [at the user level] and
then we will have a file descriptor for looking up the cid specifics?

If so then I may already basically understand what you want to have done.

> 
> 					-Matt
> 					Matthew Dillon 
> 					<dillon at xxxxxxxxxxxxx>