Anybody working on removing sendmail from base?
sander
sander at haldjas.folklore.ee
Sun Sep 28 02:58:21 PDT 2003
On Sun, 28 Sep 2003, Matthew Dillon wrote:
> I really do think that we will be able to use some sort of VFS layering
> feature to deal with default compiler selection and things like that.
> Don't think of it so much as actually creating a VFS, instead think of it
> as an abstraction many forms of which can be optimized down to a few
> permanent entries in the namecache. The /etc/rc* system would set up
> the entries when the system boots and they could also be changed at run
> time.
>
So this would essentialy be a process subtree specific union mount of
/usr/bin and nano-filesystem conataining just alternate entries for gcc,
cc, etc?
> Then consider the ability to 'stack' the abstraction ('stack' virtualized
> VFS layers) to create environments. e.g. user A might want GCC3.2 as
> the default while user B might want GCC2.95.4.
>
sure - if you can do process subtree specific stacking / mounting this
is simple.
> Now, if you can picture all of that, go back to the idea of a VFS
> 'process' running in userland, but then consider that all such a process
> really has to do is manage entries in the namecache and would only be
> messaged when the kernel can't find the request in the cache. We still
> wind up with almost 100% the performance that we would have with the
> underlying native filesystem.
>
Wouldn't it be more efficent for a selection of such cases if you just
adopted variant symlinks? You would then have
/usr/bin/gcc -> /usr/compilers/${gcc_ver}/bin/gcc
and where it points to would depend directly on environment.
> Anything we can do within the kernel's namecache is basically going to be
> freebee from a performance standpoint.
>
you have to differentiate between N versions that are in various ways
associated with calling processes though.
> -Matt
>
Sander
+++ Out of cheese error +++
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