On 7/27/2021 4:28 PM, Dr. David Alan Gilbert wrote:
* Chenyi Qiang (chenyi.qi...@intel.com) wrote:
A bus lock is acquired through either split locked access to writeback
(WB) memory or any locked access to non-WB memory. It is typically >1000
cycles slower than an atomic operation within a
* Chenyi Qiang (chenyi.qi...@intel.com) wrote:
> A bus lock is acquired through either split locked access to writeback
> (WB) memory or any locked access to non-WB memory. It is typically >1000
> cycles slower than an atomic operation within a cache and can also
> disrupts performance on other
On 6/2/2021 4:10 AM, Eduardo Habkost wrote:
On Tue, Jun 01, 2021 at 02:18:37PM -0400, Eduardo Habkost wrote:
On Mon, May 31, 2021 at 01:14:54PM +0800, Chenyi Qiang wrote:
On 5/28/2021 5:19 AM, Eduardo Habkost wrote:
On Fri, May 21, 2021 at 12:38:20PM +0800, Chenyi Qiang wrote:
[...]
@@
On Tue, Jun 01, 2021 at 02:18:37PM -0400, Eduardo Habkost wrote:
> On Mon, May 31, 2021 at 01:14:54PM +0800, Chenyi Qiang wrote:
> >
> >
> > On 5/28/2021 5:19 AM, Eduardo Habkost wrote:
> > > On Fri, May 21, 2021 at 12:38:20PM +0800, Chenyi Qiang wrote:
> > > [...]
> > > > @@ -4222,6 +4247,15 @@
On Mon, May 31, 2021 at 01:14:54PM +0800, Chenyi Qiang wrote:
>
>
> On 5/28/2021 5:19 AM, Eduardo Habkost wrote:
> > On Fri, May 21, 2021 at 12:38:20PM +0800, Chenyi Qiang wrote:
> > [...]
> > > @@ -4222,6 +4247,15 @@ void kvm_arch_pre_run(CPUState *cpu, struct
> > > kvm_run *run)
> > > }
On 5/28/2021 5:19 AM, Eduardo Habkost wrote:
On Fri, May 21, 2021 at 12:38:20PM +0800, Chenyi Qiang wrote:
[...]
@@ -4222,6 +4247,15 @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run *run)
}
}
+static void kvm_rate_limit_on_bus_lock(void)
+{
+uint64_t delay_ns =
On Fri, May 21, 2021 at 12:38:20PM +0800, Chenyi Qiang wrote:
[...]
> @@ -4222,6 +4247,15 @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run
> *run)
> }
> }
>
> +static void kvm_rate_limit_on_bus_lock(void)
> +{
> +uint64_t delay_ns =
A bus lock is acquired through either split locked access to writeback
(WB) memory or any locked access to non-WB memory. It is typically >1000
cycles slower than an atomic operation within a cache and can also
disrupts performance on other cores.
Virtual Machines can exploit bus locks to degrade