Re: /proc/<n>/maps growing...

[Andrea Arcangeli]

On Mon, Aug 06, 2001 at 06:06:14AM -0700, David S. Miller wrote:
> I wouldn't classify it as a horrible hack... but.

The part I find worse is that we just walk the tree two times.

I believe the best way is to allocate always the new vma, and to hide
the merging into the lowlevel of a new insert_vm_struct (with a special
function ala merge_segments that we can share with mprotect like in 2.2).

For example we could limit such special function to merge only the
anonymous mappings if we don't want to solve the locking issues (the
abortion), so it could remain simple but generic and optimized to avoid
walking the tree, allocating and freeing a slab cache is O(1) operation
when there's no memory pressore, much better than browsing a tree two
times at every malloc with a two liner that avoids hitting the
max_limit while we recall malloc. (of course for mremap we'll keep
browsing the tree twice but we cannot avoid that)

Andrea