* [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
@ 2017-10-10 7:11 ` Nicholas Piggin
0 siblings, 0 replies; 9+ messages in thread
From: Nicholas Piggin @ 2017-10-10 7:11 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, kvm-ppc, linux-pm
For shared processor guests (e.g., KVM), add an idle polling mode rather
than immediately returning to the hypervisor when the guest CPU goes
idle.
Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
polling idle gives about 1.4x throughput.
Kernel compile speed was not changed significantly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
drivers/cpuidle/cpuidle-pseries.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index e9b3853d93ea..16be7ad30fe1 100644
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -171,11 +171,17 @@ static struct cpuidle_state dedicated_states[] = {
* States for shared partition case.
*/
static struct cpuidle_state shared_states[] = {
+ { /* Snooze */
+ .name = "snooze",
+ .desc = "snooze",
+ .exit_latency = 0,
+ .target_residency = 0,
+ .enter = &snooze_loop },
{ /* Shared Cede */
.name = "Shared Cede",
.desc = "Shared Cede",
- .exit_latency = 0,
- .target_residency = 0,
+ .exit_latency = 10,
+ .target_residency = 100,
.enter = &shared_cede_loop },
};
--
2.13.3
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
@ 2017-10-10 7:11 ` Nicholas Piggin
0 siblings, 0 replies; 9+ messages in thread
From: Nicholas Piggin @ 2017-10-10 7:11 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, kvm-ppc, linux-pm
For shared processor guests (e.g., KVM), add an idle polling mode rather
than immediately returning to the hypervisor when the guest CPU goes
idle.
Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
polling idle gives about 1.4x throughput.
Kernel compile speed was not changed significantly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
drivers/cpuidle/cpuidle-pseries.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index e9b3853d93ea..16be7ad30fe1 100644
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -171,11 +171,17 @@ static struct cpuidle_state dedicated_states[] = {
* States for shared partition case.
*/
static struct cpuidle_state shared_states[] = {
+ { /* Snooze */
+ .name = "snooze",
+ .desc = "snooze",
+ .exit_latency = 0,
+ .target_residency = 0,
+ .enter = &snooze_loop },
{ /* Shared Cede */
.name = "Shared Cede",
.desc = "Shared Cede",
- .exit_latency = 0,
- .target_residency = 0,
+ .exit_latency = 10,
+ .target_residency = 100,
.enter = &shared_cede_loop },
};
--
2.13.3
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
2017-10-10 7:11 ` Nicholas Piggin
@ 2017-10-10 9:42 ` Nicholas Piggin
-1 siblings, 0 replies; 9+ messages in thread
From: Nicholas Piggin @ 2017-10-10 9:42 UTC (permalink / raw)
To: linuxppc-dev; +Cc: kvm-ppc, linux-pm
On Tue, 10 Oct 2017 17:11:09 +1000
Nicholas Piggin <npiggin@gmail.com> wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
Actually it's even more noticeable when the host is not over subscribed
by the looks. 2.5x-3x increase in throughput for just a single guest.
Thanks,
Nick
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
@ 2017-10-10 9:42 ` Nicholas Piggin
0 siblings, 0 replies; 9+ messages in thread
From: Nicholas Piggin @ 2017-10-10 9:42 UTC (permalink / raw)
To: linuxppc-dev; +Cc: kvm-ppc, linux-pm
On Tue, 10 Oct 2017 17:11:09 +1000
Nicholas Piggin <npiggin@gmail.com> wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
Actually it's even more noticeable when the host is not over subscribed
by the looks. 2.5x-3x increase in throughput for just a single guest.
Thanks,
Nick
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
2017-10-10 7:11 ` Nicholas Piggin
@ 2017-11-16 16:17 ` Nicholas Piggin
-1 siblings, 0 replies; 9+ messages in thread
From: Nicholas Piggin @ 2017-11-16 16:17 UTC (permalink / raw)
To: linuxppc-dev; +Cc: kvm-ppc, linux-pm
On Tue, 10 Oct 2017 17:11:09 +1000
Nicholas Piggin <npiggin@gmail.com> wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
>
> Kernel compile speed was not changed significantly.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
What should we do about this one?
> ---
> drivers/cpuidle/cpuidle-pseries.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
> index e9b3853d93ea..16be7ad30fe1 100644
> --- a/drivers/cpuidle/cpuidle-pseries.c
> +++ b/drivers/cpuidle/cpuidle-pseries.c
> @@ -171,11 +171,17 @@ static struct cpuidle_state dedicated_states[] = {
> * States for shared partition case.
> */
> static struct cpuidle_state shared_states[] = {
> + { /* Snooze */
> + .name = "snooze",
> + .desc = "snooze",
> + .exit_latency = 0,
> + .target_residency = 0,
> + .enter = &snooze_loop },
> { /* Shared Cede */
> .name = "Shared Cede",
> .desc = "Shared Cede",
> - .exit_latency = 0,
> - .target_residency = 0,
> + .exit_latency = 10,
> + .target_residency = 100,
> .enter = &shared_cede_loop },
> };
>
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
@ 2017-11-16 16:17 ` Nicholas Piggin
0 siblings, 0 replies; 9+ messages in thread
From: Nicholas Piggin @ 2017-11-16 16:17 UTC (permalink / raw)
To: linuxppc-dev; +Cc: kvm-ppc, linux-pm
On Tue, 10 Oct 2017 17:11:09 +1000
Nicholas Piggin <npiggin@gmail.com> wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
>
> Kernel compile speed was not changed significantly.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
What should we do about this one?
> ---
> drivers/cpuidle/cpuidle-pseries.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
> index e9b3853d93ea..16be7ad30fe1 100644
> --- a/drivers/cpuidle/cpuidle-pseries.c
> +++ b/drivers/cpuidle/cpuidle-pseries.c
> @@ -171,11 +171,17 @@ static struct cpuidle_state dedicated_states[] = {
> * States for shared partition case.
> */
> static struct cpuidle_state shared_states[] = {
> + { /* Snooze */
> + .name = "snooze",
> + .desc = "snooze",
> + .exit_latency = 0,
> + .target_residency = 0,
> + .enter = &snooze_loop },
> { /* Shared Cede */
> .name = "Shared Cede",
> .desc = "Shared Cede",
> - .exit_latency = 0,
> - .target_residency = 0,
> + .exit_latency = 10,
> + .target_residency = 100,
> .enter = &shared_cede_loop },
> };
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: powerpc/pseries/cpuidle: add polling idle for shared processor guests
2017-10-10 7:11 ` Nicholas Piggin
(?)
@ 2018-01-22 3:34 ` Michael Ellerman
-1 siblings, 0 replies; 9+ messages in thread
From: Michael Ellerman @ 2018-01-22 3:34 UTC (permalink / raw)
To: linuxppc-dev; +Cc: kvm-ppc, Nicholas Piggin, linux-pm
On Tue, 2017-10-10 at 07:11:09 UTC, Nicholas Piggin wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
>
> Kernel compile speed was not changed significantly.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/f2ac428e0edabbca41b9dfe9473a90
cheers
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: powerpc/pseries/cpuidle: add polling idle for shared processor guests
@ 2018-01-22 3:34 ` Michael Ellerman
0 siblings, 0 replies; 9+ messages in thread
From: Michael Ellerman @ 2018-01-22 3:34 UTC (permalink / raw)
To: Nicholas Piggin, linuxppc-dev; +Cc: kvm-ppc, Nicholas Piggin, linux-pm
On Tue, 2017-10-10 at 07:11:09 UTC, Nicholas Piggin wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
>
> Kernel compile speed was not changed significantly.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/f2ac428e0edabbca41b9dfe9473a90
cheers
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: powerpc/pseries/cpuidle: add polling idle for shared processor guests
@ 2018-01-22 3:34 ` Michael Ellerman
0 siblings, 0 replies; 9+ messages in thread
From: Michael Ellerman @ 2018-01-22 3:34 UTC (permalink / raw)
To: linuxppc-dev; +Cc: kvm-ppc, Nicholas Piggin, linux-pm
On Tue, 2017-10-10 at 07:11:09 UTC, Nicholas Piggin wrote:
> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
>
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.
>
> Kernel compile speed was not changed significantly.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/f2ac428e0edabbca41b9dfe9473a90
cheers
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2018-01-22 3:34 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-10-10 7:11 [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests Nicholas Piggin
2017-10-10 7:11 ` Nicholas Piggin
2017-10-10 9:42 ` Nicholas Piggin
2017-10-10 9:42 ` Nicholas Piggin
2017-11-16 16:17 ` Nicholas Piggin
2017-11-16 16:17 ` Nicholas Piggin
2018-01-22 3:34 ` Michael Ellerman
2018-01-22 3:34 ` Michael Ellerman
2018-01-22 3:34 ` Michael Ellerman
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