Re: [Netnice-kernels] Re: netnice on linux

[kartikey b. <kar...@ho...>]

hi,

taka wrote:

>this statement is understandable. yes, we may adopt the copy-on-write
>strategy, and if you prefer the approach, you may change the algorithm,
>as long as it is compatible with *BSD. however, the memory waste and the
>copy overhead you mentioned are negligible on most machines nowadays, and
>very few applications create and delete sockets intensively. so, it sounds
>like adding extra complexity in the code for very small gain.

i agree.

>i don't think i understand everything about your suggestion. but, this
>sounds like adding a "stack-like" structure in the association management,
>where we can easily recover former associations in an organized manner at
>any given time.

>several questoins:
>
>  - are you linking this idea with the one-process one-vif policy, you
>    suggested? if so, it confuses me, and i need more explanation.

its not one-process one-vif policy but one-process and only one association 
to the vif that connects the process to the real interface. i mean a process 
cannot have association to two different vifs that has the same reall 
interface.

>  - pvifnet is a link of VIFs associated with a terminating entity, such
>    as a process, and a socket. i believe the structure is needed to
>    properly handle multiple network interfaces, but, in the above
>    description of the algorithm, it shows only one pvifnet. is it
>    just for explanation purpose? or, are you proposing "one-process
>    one-pvifnet one-vif" model? (i hope not!)

exactly not. pvifnet is a list of all the vifs association of the process.

>  - although the stack-like management of VIF-process/socket association
>    looks interesting, i don't understand why you came up with the idea.
>    can you suggest several situations where this approach is useful?
>    when we delete a VIF-process association, we did because we want to
>    delete the association, prohibiting the process from using the
>    interface (right?). even on your scheme, we can delete the association
>    when we delete the first one. but, this obviously violates semantics
>    of "rm" (remove, or unlink) operation on NNFS (any justification?).
>    also, we can revert to the default (original) association, just by
>    copying the association of the parent process. any comment on the
>    issue?

i think when we delete the VIF-process association, we do it because we want 
to prohibit the process from using the VIF not the "interface".

we can't revert to the default association just by copying the association 
of the parent process, because in the mean time parent process might have 
created new ass ociations.

>anyway. i really appreciate your suggestions, and i do not want to
>interrupt your attempts simply because they are against my original
>design.

thanks a lot on positve feedback!

the most annoying part of the netnice is shared vifs among the parent and 
the child process. i mean when a child process modifies the vif attributes 
like bandwidth and type of the vif, it gets reflected in the parent process. 
which really shouldn't be allowed.

any suggestions for the same?

thanks
kartikey