On Tue, 21 Mar 2000, Matthew Kirkwood wrote:
> On Tue, 21 Mar 2000, Richard B. Johnson wrote:
>
> > > > Malloc(), as stated before, just sets a new break address when it
> > > > runs out of heap. It keeps track of the heap, but not very carefully.
> > >
> > > Not any more. Modern mallocs are a lot smarter. They also use mmap for
> > > their backing store
> >
> > Certainly not the C runtime library distributed by RedHat.
>
> > malloc(0x1000);
>
> glibc's malloc() will use mmap() only to allocate large lumps.
> (Currently the default is 128Kb or larger, I think.)
>
Correct. Many, in fact what looks like all, page-size chunks are
allocated using break. Try it and see. The 'set-break' goes on
forever.....
Cheers,
Dick Johnson
Penguin : Linux version 2.3.41 on an i686 machine (800.63 BogoMips).
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