Re: [Lhms-devel] Re: [RFC] free_area[] bitmap elimination [0/3]
From: Hiroyuki KAMEZAWA <hidden>
Date: 2004-08-21 05:21:42
Hi, Hirokazu Takahashi wrote:
Hi,quoted
William Lee Irwin III wrote:quoted
On Sat, Aug 21, 2004 at 11:31:21AM +0900, Hiroyuki KAMEZAWA wrote:quoted
This patch removes bitmap from buddy allocator used in alloc_pages()/free_pages() in the kernel 2.6.8.1.
<snip>
quoted
In my understanding, the patch assumes that size of mem_map[] in each zone must be multiple of 2^MAX_ORDER, right? But it doesn't seem it's a big problem, as we can just allocate extra mem_map[] to round up if it isn't.I think this may help the buddy allocator to work withtout adding page_ivs_valid(buddy1).
As you say, I expects the size of zone is multiple of MAX_ORDER. But IA64 kernel's MAX_ORDER is 4 Giga bytes :( A Tiger4, an IA64 machine, I use has physical memory map like this: 0-2G : 4-8G : 10-12G: contiguous mem_map is smaller than MAX_ORDER. So I think page_is_valid(buddy1) is needed only for a few pages, which is top of big buddy, in this case. Hmm.... :( Thank you, KAME -- --the clue is these footmarks leading to the door.-- KAMEZAWA Hiroyuki [off-list ref] -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>