On 24/03/17 18:00, Christoffer Dall wrote:
On Mon, Mar 20, 2017 at 06:26:42PM +0000, Suzuki K Poulose wrote:
In order to perform an operation on a gpa range, the hyp iterates
the hyp ?
To be precise "the host" ?
over each page in a user memory slot for the given range. This is
inefficient while dealing with a big range (e.g, a VMA), especially
while unmaping a range. At present, with stage2 unmap on a range with
a hugepage backed region, we clear the PMD when we unmap the first
page in the loop. The remaining iterations simply traverse the page table
down to the PMD level only to see that nothing is in there.
This patch reworks the code to invoke the callback handlers on the
biggest range possible within the memory slot to avoid reduce the
number of iterations.
avoid reduce?
did you mean "to reduce the number of times the handler is called" ?
Yep, thanks for spotting.
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
arch/arm/kvm/mmu.c | 31 +++++++++++++------------------
1 file changed, 13 insertions(+), 18 deletions(-)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 37e67f5..8357fed 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
...
Otherwise looks good:
I can fix up the commit message when applying this.
Reviewed-by: Christoffer Dall <cdall@xxxxxxxxxx>
Thanks
Suzuki
