Cc: Andrew Morton <akpm@...>, Dave Hansen <dave@...>, Nick Piggin <nickpiggin@...>, <hugh@...>, <menage@...>, <xemul@...>, <linux-kernel@...>, <linux-mm@...>
IIRC, (Aa + Bb) / Cc < 1.0 discussion was following.
Because we have to maintain pointer to page_cgroup in radix-tree (ZONE_NORMAL)
1. memory usage will increase when memory cgroup is enabled.
The amount memory usage increase just depends on the height of radix-tree.
2. memory usage will decrease when memory cgroup is disabled.
This saves 4bytes per 4096bytes. (on x86-32)
Thanks,
-Kame
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