[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] xen/arm: p2m: Don't create new table when the mapping is removed





On 12/18/2013 07:28 PM, Stefano Stabellini wrote:
On Wed, 18 Dec 2013, Julien Grall wrote:
When  Xen is removing/relinquishing mapping, it will create second/third tables
if they don't exist.

Non-existent table means the address range was never mapped, so Xen can safely
skip them.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>

---
     Release: This is an improvement for Xen 4.4. It will save time during
     relinquish phase and avoid dummy allocation.
     The downside is the patch is modifying p2m loop which is used everywhere.
---
  xen/arch/arm/p2m.c |   22 ++++++++++++++++++++--
  1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index d24a6fc..9ef8819 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -246,10 +246,12 @@ static int create_p2m_entries(struct domain *d,
                    cur_first_offset = ~0,
                    cur_second_offset = ~0;
      unsigned long count = 0;
+    bool_t populate = (op == INSERT || op == ALLOCATE);

why don't you just check for op == REMOVE?

Because you also need to check op == RELINQUISH (added by my patch series on foreign mapping).

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.