• K
    xen/p2m: Reuse existing P2M leafs if they are filled with 1:1 PFNs or INVALID. · 250a41e0
    Konrad Rzeszutek Wilk 提交于
    If P2M leaf is completly packed with INVALID_P2M_ENTRY or with
    1:1 PFNs (so IDENTITY_FRAME type PFNs), we can swap the P2M leaf
    with either a p2m_missing or p2m_identity respectively. The old
    page (which was created via extend_brk or was grafted on from the
    mfn_list) can be re-used for setting new PFNs.
    
    This also means we can remove git commit:
    5bc6f988
    xen/p2m: Reserve 8MB of _brk space for P2M leafs when populating back
    which tried to fix this.
    
    and make the amount that is required to be reserved much smaller.
    
    CC: stable@vger.kernel.org # for 3.5 only.
    Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
    250a41e0
p2m.c 32.8 KB