Messages in this thread | | | Date | Mon, 09 Jun 2014 13:01:44 -0700 | From | Dave Hansen <> | Subject | Re: [PATCH 2/7] mm/pagewalk: replace mm_walk->skip with more general mm_walk->control |
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On 06/06/2014 03:58 PM, Naoya Horiguchi wrote: > +enum mm_walk_control { > + PTWALK_NEXT = 0, /* Go to the next entry in the same level or > + * the next vma. This is default behavior. */ > + PTWALK_DOWN, /* Go down to lower level */ > + PTWALK_BREAK, /* Break current loop and continue from the > + * next loop */ > +};
I think this is a bad idea.
The page walker should be for the common cases of walking page tables, and it should be simple. It *HAS* to be better (shorter/faster) than if someone was to just open-code a page table walk, or it's not really useful.
The only place this is used is in the ppc walker, and it saves a single line of code, but requires some comments to explain what is going on:
arch/powerpc/mm/subpage-prot.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
So, it adds infrastructure, but saves a single line of code. Seems like a bad trade off to me. :(
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