Re: [PATCH 1/2] mm: use list.h for vma list

From: KOSAKI Motohiro
Date: Thu Mar 12 2009 - 04:33:11 EST


> On Wednesday 11 March 2009 20:55:48 Daniel Lowengrub wrote:
> > Use the linked list defined list.h for the list of vmas that's stored
> > in the mm_struct structure. Wrapper functions "vma_next" and
> > "vma_prev" are also implemented. Functions that operate on more than
> > one vma are now given a list of vmas as input.
>
> I'd love to be able to justify having a doubly linked list for vmas...
> It's easier than managing singly linked lists by hand :) So if you have
> such a good increase with lookups, it might be a good idea. I wouldn't
> like to see vm_area_struct go above 192 bytes on any config if possible
> though.

Currently, sizeof(struct vm_area_struct) on x86_64 is 176.
if we assume 32byte cache-line, 176byte is 6 cache-line.
then, making coubly linked list don't cause d-cache pollution.

Therefore, We can merge this patch after some cleanups.
(of cource, your opining cleanups is obiously necessary...)



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