On 06/03/2013 03:54:28 PM, Mihai Caraman wrote:
Adopt AltiVec approach to increase laziness by calling
kvmppc_load_guest_fp()
just before returning to guest instaed of each sched in.
Signed-off-by: Mihai Caraman <mihai.caraman@xxxxxxxxxxxxx>
If you did this *before* adding Altivec it would have saved a question
in an earlier patch. :-)
---
arch/powerpc/kvm/booke.c | 1 +
arch/powerpc/kvm/e500mc.c | 2 --
2 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 019496d..5382238 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -1258,6 +1258,7 @@ int kvmppc_handle_exit(struct kvm_run *run,
struct kvm_vcpu *vcpu,
} else {
kvmppc_lazy_ee_enable();
kvmppc_load_guest_altivec(vcpu);
+ kvmppc_load_guest_fp(vcpu);
}
}
You should probably do these before kvmppc_lazy_ee_enable().
Actually, I don't think this is a good idea at all. As I understand
it, you're not supposed to take kernel ownersship of floating point in
non-atomic context, because an interrupt could itself call
enable_kernel_fp().
Do you have benchmarks showing it's even worthwhile?
-Scott
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
