Hi,
There are several types of PG_reserved pages, (a) Memory Hole (b) Used by Kernel (c) Set by drivers (d) Isorated by MCA (e) used by perfmon etc....
I think it's useful to distinguish many types of PG_reserved pages.
For example, Memory Hotplug can ignore (a).
2 patches [1/3][2/3] are for naming PG_reserved pages. A type of a page is recoreded in page->private. I'm not sure whether this is safe or not, so only reserved-at-boot pages are named, currently.
patch [3/3] is an interface to show state of memmap, /dev/memstate.
In /dev/memstate, file offset is pfn and a byte represents a state of a page. In this patch, memory hole and Reserved pages has its value.
below is output of my box.
0xff --- Invalid page 0x00 --- Common page 0x02 --- Reserved at boot page
[EMAIL PROTECTED] char]# od -t x1 -j 0 -N 65535 /dev/memstate 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0001540 ff ff ff ff ff ff ff ff ff ff ff ff ff ff 02 02 0001560 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 * 0002400 02 02 02 00 00 00 00 00 00 02 02 02 02 02 02 02 0002420 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 * 0003400 02 02 02 02 02 02 02 02 02 02 02 00 00 00 00 00 0003420 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0010000 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 * 0010640 02 02 02 02 02 02 02 02 02 02 02 02 02 02 00 00 0010660 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
This would be useful for Memory-Hotplug and some other stuffs. I think more detailed types can be supported.
Thanks. -- Kame <[EMAIL PROTECTED]>
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
