extend dl-minimal malloc implementation

[H.J. Lu]

On Thu, Aug 17, 2017 at 6:10 AM, Zack Weinberg <zackw@panix.com> wrote:
> On Thu, Aug 17, 2017 at 2:41 AM, Andreas Schwab <schwab@suse.de> wrote:
>> On Aug 16 2017, Zack Weinberg <zackw@panix.com> wrote:
>>
>>> What I was trying to suggest, earlier, was that *before* either (a) or
>>> (b) we should go through the entire of ld.so and try to *remove* as
>>> many allocations as possible, at which point it might make sense not
>>> to have malloc in there at all - "just" send all remaining allocations
>>> directly to mmap (not sbrk; leave sbrk for the "real" malloc).  That
>>> may take rearchitecting - but so may just converting alloca to malloc,
>>> as you point out. I admit I have no idea whether this is even
>>> feasible.
>>
>> You still need something on top of mmap, unless you want to waste a lot
>> of memory.
>
> _Do_ we, though?  Why does ld.so need to make any allocations at all
> above and beyond mapping in the libraries?  It's an open question as
> far as I'm concerned.

Do we know how many calls to free within ld.so before the regular free
takes over?

-- 
H.J.