[9fans] usb audio devices list on supported pc hardware wiki page

[9fans] usb audio devices list on supported pc hardware wiki page

[Axel Belinfante]

I've added a list of usb audio devices that have been
reported to work on 9fans to the wiki in
http://plan9.bell-labs.com/wiki/plan9/Supported_PC_hardware/

could those in the know and or possessing supported devices
please correct and or add their devices?

(if providing such a detailed list is deemed not useful
 ('most will work') then someone please just revert to the
 previous version of the page)

Axel.

[9fans] xspanalloc?

[Tim Newsham]

I'm not sure I understand the intention of the xspanalloc arguments:

   void* xspanalloc(ulong size, int align, ulong span);

It seems like the "align" and "span" arguments are used in similar
ways.  However, when using the "align" argument, the scrap space
allocated is never freed.  The "align" case does free up memory
but also has a 2nd freeing operation that looks strange.  What
are the semantics of these arguments?

Tim N.

Re: [9fans] xspanalloc?

[Russ Cox]

xspanalloc is intended to be called only a few times
and can stand to leak.  there is now a mallocalign
that takes the same arguments but can be freed.

align says "align this on an n-byte boundary".
span says "don't cross an n-byte boundary".

it's true that align implies span, but it doesn't
make a very good implementation of span.
consider allocating 32 bytes that cannot span
a kilobyte boundary.  there are a lot more choices
than when allocating 32 bytes that are aligned on
a kilobyte boundary.

russ

On Mon, 3 Jan 2005 15:21:33 -1000 (HST), Tim Newsham <newsham@lava.net> wrote:
> I'm not sure I understand the intention of the xspanalloc arguments:
> 
>    void* xspanalloc(ulong size, int align, ulong span);
> 
> It seems like the "align" and "span" arguments are used in similar
> ways.  However, when using the "align" argument, the scrap space
> allocated is never freed.  The "align" case does free up memory
> but also has a 2nd freeing operation that looks strange.  What
> are the semantics of these arguments?
> 
> Tim N.
>