mirror of
https://github.com/torvalds/linux.git
synced 2024-11-07 20:51:47 +00:00
3fc509fc0c
When we free the PFNs and then subsequently populate them back during bootup: Freeing 20000-20200 pfn range: 512 pages freed 1-1 mapping on 20000->20200 Freeing 40000-40200 pfn range: 512 pages freed 1-1 mapping on 40000->40200 Freeing bad80-badf4 pfn range: 116 pages freed 1-1 mapping on bad80->badf4 Freeing badf6-bae7f pfn range: 137 pages freed 1-1 mapping on badf6->bae7f Freeing bb000-100000 pfn range: 282624 pages freed 1-1 mapping on bb000->100000 Released 283999 pages of unused memory Set 283999 page(s) to 1-1 mapping Populating 1acb8a-1f20e9 pfn range: 283999 pages added We end up having the P2M array (that is the one that was grafted on the P2M tree) filled with IDENTITY_FRAME or INVALID_P2M_ENTRY) entries. The patch titled "xen/p2m: Reuse existing P2M leafs if they are filled with 1:1 PFNs or INVALID." recycles said slots and replaces the P2M tree leaf's with &mfn_list[xx] with p2m_identity or p2m_missing. And re-uses the P2M array sections for other P2M tree leaf's. For the above mentioned bootup excerpt, the PFNs at 0x20000->0x20200 are going to be IDENTITY based: P2M[0][256][0] -> P2M[0][257][0] get turned in IDENTITY_FRAME. We can re-use that and replace P2M[0][256] to point to p2m_identity. The "old" page (the grafted P2M array provided by Xen) that was at P2M[0][256] gets put somewhere else. Specifically at P2M[6][358], b/c when we populate back: Populating 1acb8a-1f20e9 pfn range: 283999 pages added we fill P2M[6][358][0] (and P2M[6][358], P2M[6][359], ...) with the new MFNs. That is all OK, except when we revector we assume that the PFN count would be the same in the grafted P2M array and in the newly allocated. Since that is no longer the case, as we have holes in the P2M that point to p2m_missing or p2m_identity we have to take that into account. [v2: Check for overflow] [v3: Move within the __va check] [v4: Fix the computation] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> |
||
|---|---|---|
| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| ia32 | ||
| include/asm | ||
| kernel | ||
| kvm | ||
| lguest | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| pci | ||
| platform | ||
| power | ||
| realmode | ||
| syscalls | ||
| tools | ||
| um | ||
| vdso | ||
| video | ||
| xen | ||
| .gitignore | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Makefile | ||
| Makefile_32.cpu | ||
| Makefile.um | ||