Re: [PATCH 3/3] mm/mmap.c: extract __vma_unlink_list as counter part for __vma_link_list

From: Matthew Wilcox
Date: Tue Aug 20 2019 - 13:26:34 EST


On Wed, Aug 14, 2019 at 11:19:37AM +0200, Vlastimil Babka wrote:
> On 8/14/19 8:57 AM, Wei Yang wrote:
> > On Tue, Aug 13, 2019 at 10:16:11PM -0700, Christoph Hellwig wrote:
> >>Btw, is there any good reason we don't use a list_head for vma linkage?
> >
> > Not sure, maybe there is some historical reason?
>
> Seems it was single-linked until 2010 commit 297c5eee3724 ("mm: make the vma
> list be doubly linked") and I guess it was just simpler to add the vm_prev link.
>
> Conversion to list_head might be an interesting project for some "advanced
> beginner" in the kernel :)

I'm working to get rid of vm_prev and vm_next, so it would probably be
wasted effort.