Re: Problem in Page Cache Replacement

Fengguang Wu
2012-11-23T02:26:09Z

Jaegeuk,

> Thanks for your response. But which kind of pages are in the special
> reserved and which are all-flags-cleared?

The all-flags-cleared pages are mostly free pages in the buddy system.
The pages with flag "buddy" are also free pages: the buddy system only
marks the head pages of each order-2 free range with flag "buddy".

The reserved pages come from many sources, they may be set for memory
reserved for BIOS, memory holes, offlined memory, or used by some
device drivers.

Thanks,
Fengguang