KThreadLocalPage

Size : 0x18 bytes

Offset	Type	Description
0x0	u32	Pointer to memory page used for thread local regions for threads owned by a given process
0x4	KProcess*	Owner process
0x8	u32	Number of threads owned by the process
0xC	char[8]	Used to track the usage of thread local regions in the local page.
0x14	u32	Zero

The 8-byte array used to track the regions in use in the page works like so:

Each char is either 1 or 0, and there's one char per thread local region. 0x200 bytes per region * 8 regions is 0x1000 bytes or 1 full page. The chars are set to 1 to indicate the region is unused and 0 to indicate the region is in use.