Messages in this thread | | | Date | Fri, 3 Jun 2011 00:54:39 +0900 | Subject | Re: [patch 8/8] mm: make per-memcg lru lists exclusive | From | Hiroyuki Kamezawa <> |
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2011/6/2 Johannes Weiner <hannes@cmpxchg.org>: > On Thu, Jun 02, 2011 at 10:16:59PM +0900, Hiroyuki Kamezawa wrote: >> 2011/6/1 Johannes Weiner <hannes@cmpxchg.org>: >> > All lru list walkers have been converted to operate on per-memcg >> > lists, the global per-zone lists are no longer required. >> > >> > This patch makes the per-memcg lists exclusive and removes the global >> > lists from memcg-enabled kernels. >> > >> > The per-memcg lists now string up page descriptors directly, which >> > unifies/simplifies the list isolation code of page reclaim as well as >> > it saves a full double-linked list head for each page in the system. >> > >> > At the core of this change is the introduction of the lruvec >> > structure, an array of all lru list heads. It exists for each zone >> > globally, and for each zone per memcg. All lru list operations are >> > now done in generic code against lruvecs, with the memcg lru list >> > primitives only doing accounting and returning the proper lruvec for >> > the currently scanned memcg on isolation, or for the respective page >> > on putback. >> > >> > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> >> >> >> could you divide this into >> - introduce lruvec >> - don't record section? information into pc->flags because we see >> "page" on memcg LRU >> and there is no requirement to get page from "pc". >> - remove pc->lru completely > > Yes, that makes sense. It shall be fixed in the next version. >
BTW, IIUC, Transparent hugepage has a code to link a page to the page->lru directly. And recent Minchan's work does the same kind of trick.
But it may put a page onto wrong memcgs if we do link a page to another page's page->lru because 2 pages may be in different cgroup each other.
Could you check there are more codes which does link page->lru to nearby page's page->lru ? Now, I'm not sure there are other codes....but we need care.
Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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