Re: [patch v2] epoll use a single inode ...

[Linus Torvalds]

On Mon, 5 Mar 2007, Davide Libenzi wrote:

> On Mon, 5 Mar 2007, Linus Torvalds wrote:
> > 
> > It's much better to do something like
> > 
> > 	static unsigned int epoll_inode;
> > 
> > 	this.len = sprintf(name, "[%u]", ++epoll_inode);
> > 
> > if you just need some pseudo-unique name to distinguish two epoll things 
> > from each other (vs from a dup'ed fd).
> 
> Heh, this is what Al was saying ;)
> I'm fine with that, but how about counter cycles (going back to zero)? 
> Should we care to handle them correctly? 

Since this is not actually *used* for anything but showing the fd's in 
/proc/<pid>/fd/ etc, no. In fact, an integer will wrap a *lot* less than a 
kernel data structure will be re-used, so even with the simple "wraps 
every 4G uses", you're still better off.

IOW, if the thing actually _mattered_ we should use some bitmap allocator 
or similar (eg pidmaps etc), but with something where the only reason 
really is as a visible indicator of difference for a user that happens to 
look, simple-and-stupid is better.

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