On Mon, May 03, 2010 at 07:11:19PM +0200, Peter Zijlstra wrote: > On Mon, 2010-05-03 at 19:02 +0200, Andrea Arcangeli wrote: > > On Mon, May 03, 2010 at 06:55:12PM +0200, Peter Zijlstra wrote: > > > This does leave me worrying about concurrent faults poking at > > > vma->vm_end without synchronization. > > > > I didn't check this patch in detail yet. I agree it can be removed and > > I think it can be safely replaced with the page_table_lock. > > Sure, it could probably be replaced with the ptl, but a single > anon_vma->lock would I think be better since there's more of them. ptl not enough, or it'd break if stack grows fast more than the size of one pmd, page_table_lock enough instead. Keeping anon_vma lock is sure fine with me ;), I was informally asked if it was a must have, and I couldn't foresee any problem in _replacing_ it (not removing) with page_table_lock (which I hope I mentioned in my answer ;). But I never had an interest to remove it, just I couldn't find any good reason to keep it either other than "paranoid just in case", which is good enough justification to me ;) considering these archs are uncommon and by definition gets less testing. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>