Messages in this thread | | | Date | Thu, 18 Sep 2008 13:43:04 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC][PATCH] Remove cgroup member from struct page (v3) |
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On Wed, 17 Sep 2008 18:40:08 -0700 Andrew Morton <akpm@linux-foundation.org> wrote: > > Advantages of the patch > > > > 1. It removes the extra pointer in struct page > > > > Disadvantages > > > > 1. Radix tree lookup is not an O(1) operation, once the page is known > > getting to the page_cgroup (pc) is a little more expensive now. > > Why are we doing this? I can guess, but I'd rather not have to. > > a) It's slower. > > b) It uses even more memory worst-case. > > c) It uses less memory best-case. > > someone somewhere decided that (Aa + Bb) / Cc < 1.0. What are the values > of A, B and C and where did they come from? ;) >
Balbir, don't you like pre-allocate-page-cgroup-at-boot at all ? I don't like radix-tree for objects which can spread to very vast/sparse area ;)
BTW, I already have lazy-lru-by-pagevec protocol on my patch(hash version) and seems to work well. I'm now testing it and will post today if I'm enough lucky.
Thanks, -Kame
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