Re: Benchmarking objrmap under memory pressure

Andrea Arcangeli
2004-04-15T14:08:50Z

On Thu, Apr 15, 2004 at 02:45:21PM +0100, Hugh Dickins wrote:
> I like file vma merging, but I am puzzled why we (you) bothered
> to implement anon vma merging before and not file vma merging,
> if the file vma merging is so much more important. I suppose
> it's something you learnt later, or the apps evolved.

both things, I learnt it later, but it's also because the anon-vma
pretty much "forced" me not to be lazy about the inodes ;). It's
something I planned already when I changed the mmap mering to handle
inodes too and submitted to Andrew that merged it in 2.5 mainline, the
only reason I didn't do it at that time, is that it was originally
developed for 2.4, and the less changes the better, so at that time I
only fixed the showstopper inode-merging for mmap and not mprotect.

At 2.4 time I also planned eventually to add the vma merging to mlock
but it didn't happen yet ;).

> Indeed. If anonmm does live on, I would want to add the file
> vma merging; but when things (mpol, prio_tree, i_shared locking)
> have settled down rather than now - we've lived without it for
> some years, can live without it for a few weeks more.

Sure.