Re: Would SSI clustering extensions be of interest to kernelcommunity?

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

Ar Llu, 2006-10-16 am 16:07 +0200, ysgrifennodd Constantine Gavrilov:
> SSI intrudes kernel in two places: a) IO system calls, b ) page fault
> code for shared memory pages.
> 
> a) IO system calls are "packed" and forwarded to the "home" node,
> where original syscall code is executed. 
> b) A hook is inserted into page fault code that brings shared memory
> pages from other nodes when necessary.
> 
> Apart from these two hooks, SSI code is a "standalone" kernel API
> add-on ("add", not "change").
> 
> Currently, we can do both "intrusions" from the kernel module. I
> assume that if we submit code, you will require a kernel patch that
> explicitly calls our hooks. 

Yep. Thats probably the most critical single thing to review.
> 
> Also, continuous SSI in-kernel support may require SSI changes in the
> following cases: a) new fields in task struct that reflect process
> state (may affect task migration), b) changes in the page fault
> mechanism (may effect SSI shared memory code that brings and
> invalidates pages), c) addition of new system calls (may require
> implementation of  SSI suspport for them).

SSI changes triggered from core changes are fairly expected I think
because you need to serialize new objects.