Messages in this thread | | | Date | Sun, 02 Nov 2014 23:22:45 -0500 (EST) | Subject | Re: [patch 1/3] mm: embed the memcg pointer directly into struct page | From | David Miller <> |
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From: Johannes Weiner <hannes@cmpxchg.org> Date: Sat, 1 Nov 2014 23:15:54 -0400
> Memory cgroups used to have 5 per-page pointers. To allow users to > disable that amount of overhead during runtime, those pointers were > allocated in a separate array, with a translation layer between them > and struct page. > > There is now only one page pointer remaining: the memcg pointer, that > indicates which cgroup the page is associated with when charged. The > complexity of runtime allocation and the runtime translation overhead > is no longer justified to save that *potential* 0.19% of memory. With > CONFIG_SLUB, page->mem_cgroup actually sits in the doubleword padding > after the page->private member and doesn't even increase struct page, > and then this patch actually saves space. Remaining users that care > can still compile their kernels without CONFIG_MEMCG. > > text data bss dec hex filename > 8828345 1725264 983040 11536649 b00909 vmlinux.old > 8827425 1725264 966656 11519345 afc571 vmlinux.new > > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Looks great:
Acked-by: David S. Miller <davem@davemloft.net>
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