Re: PR 30089: Fix ICE in operand allocation

[Andrew MacLeod <amacleod at redhat dot com>]

On Thu, 2006-12-14 at 11:32 -0500, Diego Novillo wrote:
> Jan Hubicka wrote on 12/14/06 11:24:
> > Hi,
> >> It may be, yes.  We shouldn't need the static buffer for long, 
> >> hopefully.  Andrew is changing this code.  I will try to adjust it down 
> >> in the meantime.
> > 
> > looks like I incorrectly blamed you instead of myself.  At least one
> > problem is that statement annotation grew up rather than reduced with my
> > histogram change.  This is because I moved bitfields down in the
> > structure to allow better packing on 64bit and wrongly updated after
> > your merge.
> > 
> OK.  I did one run with a reduced buffer size but, strangely, in some 
> cases I got slight memory usage *increases*.  I only test by looking at 
> the last column of -ftime-report, so I don't know how precise that is.


IN theory, that doesn't suprise me either. right now, when we ask for a
chunk that is larger than what remains in the buffer, we simply throw
away the remaining chunk and allocate a new buffer. So when you allocate
a lot of SMALL buffers, you would see more of this end-chunk waste. I
imagine it would add up.

That will all be resolved when I start reclaiming VOP memory of course.

Anrew