Re: [Linux-ia64] Fix for for memory leak in IA32 mmap

[David Mosberger <davidm@napali.hpl.hp.com>]

>>>>> On Tue, 5 Mar 2002 10:46:29 -0700, Don Dugger <n0ano@n0ano.com> said:

  Don> David- Yep, it was a virtual memory leak.  Intel came up with a
  Don> Fortran program that was allocating and freeing lots of
  Don> anonymous `mmap's.  It was really nasty because it wasn't even
  Don> the same request all the time, it had something like 3
  Don> different odd size requests that it was `mmap'ing and
  Don> `munmap'ing, all in a loop and eventually it ran out of VM.

OK, thanks for the background.

  Don> I like the idea of keeping a bitmap.  I still have to keep a
  Don> list, it'll actually be a bigger list since I'll have to keep
  Don> track of fixed requests also, but that should handle ALL cases
  Don> (even the case where a program makes an odd sized non-fixed
  Don> `mmap' followed by a fixed `mmap' into the middle of the last
  Don> page).  Give me a few days and I'll see if I can't come up with
  Don> something.

Yes, I agree: the list is still needed and an entry needs to be
created whenever an ia64 page is partially mapped.

Thanks,

	--david