Re: PATCH - raise max_anon limit

[Tim Hockin <thockin@sun.com>]

On Wed, Feb 11, 2004 at 04:42:33PM -0800, Andrew Morton wrote:
On Wed, Feb 11, 2004 at 04:42:33PM -0800, Andrew Morton wrote:
> > Indeed.  MKDEV() already masks off the high order stuff, so that is OK.
>_
> That means that we've lost the original idr key and can no longer remove
> the thing, doesn't it?

No, it doesn't store the counter with the id.  They expect you to do that.
My best understanding is that thi sis to prevent re-use of the same key.
I'm not sure I grok why it is useful.  If you release a key, it should be
safe to reuse.  Period.  I assume there was some use case that brought about
this "feature" but if so, I don't know what it is.  The big comment about it
is just confusing me.

> > On idr_get_new(), we can just check for
> > 	dev & ((1<<MINORBITS)-1) == (1<<MINORBITS)-1)
> > and return -EMFILE.
> >_
> > That combined with a gfp mask to idr and the assumption that idr's
> > counter
> > won't ever grow beyond (sizeof(int)*8 - MINORBITS) (12) bits
> >_
> > Shall I whip that up and test it?  Do you prefer a gfp mask to idr_init
> > that
> > sticks around for all allocations or a GFP mask to idr_pre_get?

Offer repeated. :)

-- 
Tim Hockin
Sun Microsystems, Linux Software Engineering
thockin@sun.com
All opinions are my own, not Sun's