Re: [Lse-tech] [PATCH] new bitmap list format (for cpusets)

Paul Jackson
2004-08-05T21:47:34Z

Martin asks:
> Can't we just do this up in userspace, ...

Aha - I was expecting this question. Howdy.

We could, I suppose (do this fancy bitmap formatting in userland).

It's certainly been a pleasure to Simon Derr, Sylvain Jeaugey and
myself, over the last six months, to be able to easily manipulate
these big masks using classic Unix commands like cat and echo.

The ability to atomically update a mask is unique to this interface.
The existing bitmap_parse/bitmap_scnprintf interface only allows
for a complete rewrite, not atomically adding or removing a node.

However, I am not aware of a reason why we need the atomic update.

Simon ... could you comment on this, and perhaps better motivate
this new bitmap list format?

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.650.933.1373