lkml.org 
[lkml]   [1999]   [Dec]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Binary drivers
From
Date
Bill Huey <billh@burn.ucsd.edu> writes:

> > I don't think so. Implementing a binary compatible API usually requires a
> > level of indirection that makes optimizations like inlining impossible.
>
> [here it goes, with a possible foot in the mouth ;-)]
>
> Uh, how ?

To preserve binary compatibility, you have to account for things like
structure layout and size changes. One way to do that is to hide structures
behind a pointer, IOW replace structures with a pointer to an opaque
structure. Access to such strucures is then provided through functions which
can't be inlined without exposing the layout, precisely what you were trying
to avoid.

> The header files needs to include for module compilation is identical
> for both open source and binary only modules.

Says who?

> Plus code changes that affect modules seems pretty minimal across kernel
> revisions. I'm not an authority about this.
>
> > > Solaris, Netware, QNX, BeOS, MacOS or any other commercial OS. Fact
> > > is they all use binary device drivers, and many of them are a lot
> > > more stable than Linux is.
>
> > .... and a _lot_ slower on the same hardware.
>
> Well, they're alot slower only in different circumstances for reason not
> relevant to binary-only module support.

How do you know? Have you seen the source code? Isn't it possible that the
ABI is a contributing factor (to lacklustre performace)? Okay, that still
doesn't mean that it's impossible to design an ABI that doesn't have a
performance impact. So, show us your design.

--
tim writer <tim@starnix.com> starnix inc.
tollfree: 1-87-pro-linux brampton, ontario, canada
http://www.starnix.com professional linux services & products

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:55    [W:0.051 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site