On Thu, Apr 03, 2014 at 10:57:18PM -0400, Waiman Long wrote:
On 04/03/2014 01:23 PM, Konrad Rzeszutek Wilk wrote:Huh? -EPARSE
On Wed, Apr 02, 2014 at 10:10:17PM -0400, Waiman Long wrote:The RHEL7 code has used PV ticketlock already. RHEL7 uses a single
On 04/02/2014 04:35 PM, Waiman Long wrote:Yes.
On 04/02/2014 10:32 AM, Konrad Rzeszutek Wilk wrote:BTW, does the halting and sending IPI mechanism work in HVM? I saw
On Wed, Apr 02, 2014 at 09:27:29AM -0400, Waiman Long wrote:Thank for reporting that. I haven't done that much testing on Xen.
N.B. Sorry for the duplicate. This patch series were resent as theFYI, your v7 patch with 32 VCPUs (on a 32 cpu socket machine) on an
original one was rejected by the vger.kernel.org list server
due to long header. There is no change in content.
v7->v8:
- Remove one unneeded atomic operation from the slowpath, thus
improving performance.
- Simplify some of the codes and add more comments.
- Test for X86_FEATURE_HYPERVISOR CPU feature bit to enable/disable
unfair lock.
- Reduce unfair lock slowpath lock stealing frequency depending
on its distance from the queue head.
- Add performance data for IvyBridge-EX CPU.
HVM guest under Xen after a while stops working. The workload
is doing 'make -j32' on the Linux kernel.
Completely unresponsive. Thoughts?
My focus was in KVM. I will perform more test on Xen to see if I
can reproduce the problem.
that in RHEL7, PV spinlock was explicitly disabled when in HVM mode.The PV ticketlock fixed it for HVM. It was disabled before because
However, this piece of code isn't in upstream code. So I wonder if
there is problem with that.
the PV guests were using bytelocks while the HVM were using ticketlocks
and you couldnt' swap in PV bytelocks for ticketlocks during startup.
kernel for all configurations. So PV ticketlock as well as Xen and
KVM support was compiled in. I think booting the kernel on bare
metal will cause the Xen code to work in HVM mode thus activating
the PV spinlock code which has a negative impact on performance.
That may be why it was disabled so that the bare metal performanceI am not following you.
will not be impacted.