drivers/idle/intel_idle.c | 2 -- 1 file changed, 2 deletions(-)
This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a.
Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with
boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs
in (and leave them online) which weren't supposed to be online.
With the revert and nosmt and maxcpus=12 on a raptor lake:
cpu online capacity
cpu0 1 1009
cpu1 0 -
cpu2 1 1009
cpu3 0 -
cpu4 1 1009
cpu5 0 -
cpu6 1 1009
cpu7 0 -
cpu8 1 1024
cpu9 0 -
cpu10 1 1024
cpu11 0 -
cpu12 1 1009
cpu13 0 -
cpu14 1 1009
cpu15 0 -
cpu16 1 623
cpu17 1 623
cpu18 1 623
cpu19 1 623
cpu20 0 -
cpu21 0 -
cpu22 0 -
cpu23 0 -
Previously:
cpu online capacity
cpu0 1 1009
cpu1 0 -
cpu2 1 1009
cpu3 0 -
cpu4 1 1009
cpu5 0 -
cpu6 1 1009
cpu7 0 -
cpu8 1 1024
cpu9 0 -
cpu10 1 1024
cpu11 0 -
cpu12 1 1009
cpu13 0 -
cpu14 1 1009
cpu15 0 -
cpu16 1 623
cpu17 1 623
cpu18 1 623
cpu19 1 623
cpu20 1 623
cpu21 1 623
cpu22 1 623
cpu23 1 623
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
---
Rafael, I don't immediately see how to fix this properly so I won't
try to, feel free to treat this as a bug report.
drivers/idle/intel_idle.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 91a7b7e7c0c8..a9c58395a425 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -2507,8 +2507,6 @@ static int __init intel_idle_init(void)
pr_debug("Local APIC timer is reliable in %s\n",
boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
- arch_cpu_rescan_dead_smt_siblings();
-
return 0;
hp_setup_fail:
--
2.34.1On Thu, Aug 28, 2025 at 4:26 PM Christian Loehle
<christian.loehle@arm.com> wrote:
>
> This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a.
>
> Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with
> boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs
> in (and leave them online) which weren't supposed to be online.
>
> With the revert and nosmt and maxcpus=12 on a raptor lake:
> cpu online capacity
> cpu0 1 1009
> cpu1 0 -
> cpu2 1 1009
> cpu3 0 -
> cpu4 1 1009
> cpu5 0 -
> cpu6 1 1009
> cpu7 0 -
> cpu8 1 1024
> cpu9 0 -
> cpu10 1 1024
> cpu11 0 -
> cpu12 1 1009
> cpu13 0 -
> cpu14 1 1009
> cpu15 0 -
> cpu16 1 623
> cpu17 1 623
> cpu18 1 623
> cpu19 1 623
> cpu20 0 -
> cpu21 0 -
> cpu22 0 -
> cpu23 0 -
>
> Previously:
> cpu online capacity
> cpu0 1 1009
> cpu1 0 -
> cpu2 1 1009
> cpu3 0 -
> cpu4 1 1009
> cpu5 0 -
> cpu6 1 1009
> cpu7 0 -
> cpu8 1 1024
> cpu9 0 -
> cpu10 1 1024
> cpu11 0 -
> cpu12 1 1009
> cpu13 0 -
> cpu14 1 1009
> cpu15 0 -
> cpu16 1 623
> cpu17 1 623
> cpu18 1 623
> cpu19 1 623
> cpu20 1 623
> cpu21 1 623
> cpu22 1 623
> cpu23 1 623
>
> Signed-off-by: Christian Loehle <christian.loehle@arm.com>
> ---
> Rafael, I don't immediately see how to fix this properly so I won't
> try to, feel free to treat this as a bug report.
Sure, thanks for reporting this!
Well, I think that cpuhp_smt_enable() is missing a check. It looks to
me like it should do the topology_is_primary_thread(cpu) check like
cpuhp_smt_disable().
I'll cut a test patch for this later.
> drivers/idle/intel_idle.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
> index 91a7b7e7c0c8..a9c58395a425 100644
> --- a/drivers/idle/intel_idle.c
> +++ b/drivers/idle/intel_idle.c
> @@ -2507,8 +2507,6 @@ static int __init intel_idle_init(void)
> pr_debug("Local APIC timer is reliable in %s\n",
> boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
>
> - arch_cpu_rescan_dead_smt_siblings();
> -
> return 0;
>
> hp_setup_fail:
> --
On Thu, Aug 28, 2025 at 4:44 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Thu, Aug 28, 2025 at 4:26 PM Christian Loehle > <christian.loehle@arm.com> wrote: > > > > This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a. > > > > Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with > > boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs > > in (and leave them online) which weren't supposed to be online. > > > > With the revert and nosmt and maxcpus=12 on a raptor lake: > > cpu online capacity > > cpu0 1 1009 > > cpu1 0 - > > cpu2 1 1009 > > cpu3 0 - > > cpu4 1 1009 > > cpu5 0 - > > cpu6 1 1009 > > cpu7 0 - > > cpu8 1 1024 > > cpu9 0 - > > cpu10 1 1024 > > cpu11 0 - > > cpu12 1 1009 > > cpu13 0 - > > cpu14 1 1009 > > cpu15 0 - > > cpu16 1 623 > > cpu17 1 623 > > cpu18 1 623 > > cpu19 1 623 > > cpu20 0 - > > cpu21 0 - > > cpu22 0 - > > cpu23 0 - > > > > Previously: > > cpu online capacity > > cpu0 1 1009 > > cpu1 0 - > > cpu2 1 1009 > > cpu3 0 - > > cpu4 1 1009 > > cpu5 0 - > > cpu6 1 1009 > > cpu7 0 - > > cpu8 1 1024 > > cpu9 0 - > > cpu10 1 1024 > > cpu11 0 - > > cpu12 1 1009 > > cpu13 0 - > > cpu14 1 1009 > > cpu15 0 - > > cpu16 1 623 > > cpu17 1 623 > > cpu18 1 623 > > cpu19 1 623 > > cpu20 1 623 > > cpu21 1 623 > > cpu22 1 623 > > cpu23 1 623 > > > > Signed-off-by: Christian Loehle <christian.loehle@arm.com> > > --- > > Rafael, I don't immediately see how to fix this properly so I won't > > try to, feel free to treat this as a bug report. > > Sure, thanks for reporting this! > > Well, I think that cpuhp_smt_enable() is missing a check. It looks to > me like it should do the topology_is_primary_thread(cpu) check like > cpuhp_smt_disable(). > > I'll cut a test patch for this later. Something like the attached one, perhaps. I haven't tested it yet, but I'll do that later.
On Thu, Aug 28, 2025 at 6:13 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Thu, Aug 28, 2025 at 4:44 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > On Thu, Aug 28, 2025 at 4:26 PM Christian Loehle > > <christian.loehle@arm.com> wrote: > > > > > > This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a. > > > > > > Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with > > > boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs > > > in (and leave them online) which weren't supposed to be online. > > > > > > With the revert and nosmt and maxcpus=12 on a raptor lake: > > > cpu online capacity > > > cpu0 1 1009 > > > cpu1 0 - > > > cpu2 1 1009 > > > cpu3 0 - > > > cpu4 1 1009 > > > cpu5 0 - > > > cpu6 1 1009 > > > cpu7 0 - > > > cpu8 1 1024 > > > cpu9 0 - > > > cpu10 1 1024 > > > cpu11 0 - > > > cpu12 1 1009 > > > cpu13 0 - > > > cpu14 1 1009 > > > cpu15 0 - > > > cpu16 1 623 > > > cpu17 1 623 > > > cpu18 1 623 > > > cpu19 1 623 > > > cpu20 0 - > > > cpu21 0 - > > > cpu22 0 - > > > cpu23 0 - > > > > > > Previously: > > > cpu online capacity > > > cpu0 1 1009 > > > cpu1 0 - > > > cpu2 1 1009 > > > cpu3 0 - > > > cpu4 1 1009 > > > cpu5 0 - > > > cpu6 1 1009 > > > cpu7 0 - > > > cpu8 1 1024 > > > cpu9 0 - > > > cpu10 1 1024 > > > cpu11 0 - > > > cpu12 1 1009 > > > cpu13 0 - > > > cpu14 1 1009 > > > cpu15 0 - > > > cpu16 1 623 > > > cpu17 1 623 > > > cpu18 1 623 > > > cpu19 1 623 > > > cpu20 1 623 > > > cpu21 1 623 > > > cpu22 1 623 > > > cpu23 1 623 > > > > > > Signed-off-by: Christian Loehle <christian.loehle@arm.com> > > > --- > > > Rafael, I don't immediately see how to fix this properly so I won't > > > try to, feel free to treat this as a bug report. > > > > Sure, thanks for reporting this! > > > > Well, I think that cpuhp_smt_enable() is missing a check. It looks to > > me like it should do the topology_is_primary_thread(cpu) check like > > cpuhp_smt_disable(). > > > > I'll cut a test patch for this later. > > Something like the attached one, perhaps. I haven't tested it yet, > but I'll do that later. Works here AFAICS, but my test system is not hybrid.
On 8/28/25 20:06, Rafael J. Wysocki wrote: > On Thu, Aug 28, 2025 at 6:13 PM Rafael J. Wysocki <rafael@kernel.org> wrote: >> >> On Thu, Aug 28, 2025 at 4:44 PM Rafael J. Wysocki <rafael@kernel.org> wrote: >>> >>> On Thu, Aug 28, 2025 at 4:26 PM Christian Loehle >>> <christian.loehle@arm.com> wrote: >>>> >>>> This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a. >>>> >>>> Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with >>>> boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs >>>> in (and leave them online) which weren't supposed to be online. >>>> >>>> With the revert and nosmt and maxcpus=12 on a raptor lake: >>>> cpu online capacity >>>> cpu0 1 1009 >>>> cpu1 0 - >>>> cpu2 1 1009 >>>> cpu3 0 - >>>> cpu4 1 1009 >>>> cpu5 0 - >>>> cpu6 1 1009 >>>> cpu7 0 - >>>> cpu8 1 1024 >>>> cpu9 0 - >>>> cpu10 1 1024 >>>> cpu11 0 - >>>> cpu12 1 1009 >>>> cpu13 0 - >>>> cpu14 1 1009 >>>> cpu15 0 - >>>> cpu16 1 623 >>>> cpu17 1 623 >>>> cpu18 1 623 >>>> cpu19 1 623 >>>> cpu20 0 - >>>> cpu21 0 - >>>> cpu22 0 - >>>> cpu23 0 - >>>> >>>> Previously: >>>> cpu online capacity >>>> cpu0 1 1009 >>>> cpu1 0 - >>>> cpu2 1 1009 >>>> cpu3 0 - >>>> cpu4 1 1009 >>>> cpu5 0 - >>>> cpu6 1 1009 >>>> cpu7 0 - >>>> cpu8 1 1024 >>>> cpu9 0 - >>>> cpu10 1 1024 >>>> cpu11 0 - >>>> cpu12 1 1009 >>>> cpu13 0 - >>>> cpu14 1 1009 >>>> cpu15 0 - >>>> cpu16 1 623 >>>> cpu17 1 623 >>>> cpu18 1 623 >>>> cpu19 1 623 >>>> cpu20 1 623 >>>> cpu21 1 623 >>>> cpu22 1 623 >>>> cpu23 1 623 >>>> >>>> Signed-off-by: Christian Loehle <christian.loehle@arm.com> >>>> --- >>>> Rafael, I don't immediately see how to fix this properly so I won't >>>> try to, feel free to treat this as a bug report. >>> >>> Sure, thanks for reporting this! >>> >>> Well, I think that cpuhp_smt_enable() is missing a check. It looks to >>> me like it should do the topology_is_primary_thread(cpu) check like >>> cpuhp_smt_disable(). >>> >>> I'll cut a test patch for this later. >> >> Something like the attached one, perhaps. I haven't tested it yet, >> but I'll do that later. > > Works here AFAICS, but my test system is not hybrid. Yep, on my end as well, thanks! Tested-by: Christian Loehle <christian.loehle@arm.com>
On Thu, Aug 28, 2025 at 11:44 PM Christian Loehle <christian.loehle@arm.com> wrote: > > On 8/28/25 20:06, Rafael J. Wysocki wrote: > > On Thu, Aug 28, 2025 at 6:13 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > >> > >> On Thu, Aug 28, 2025 at 4:44 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > >>> > >>> On Thu, Aug 28, 2025 at 4:26 PM Christian Loehle > >>> <christian.loehle@arm.com> wrote: > >>>> > >>>> This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a. > >>>> > >>>> Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with > >>>> boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs > >>>> in (and leave them online) which weren't supposed to be online. > >>>> > >>>> With the revert and nosmt and maxcpus=12 on a raptor lake: > >>>> cpu online capacity > >>>> cpu0 1 1009 > >>>> cpu1 0 - > >>>> cpu2 1 1009 > >>>> cpu3 0 - > >>>> cpu4 1 1009 > >>>> cpu5 0 - > >>>> cpu6 1 1009 > >>>> cpu7 0 - > >>>> cpu8 1 1024 > >>>> cpu9 0 - > >>>> cpu10 1 1024 > >>>> cpu11 0 - > >>>> cpu12 1 1009 > >>>> cpu13 0 - > >>>> cpu14 1 1009 > >>>> cpu15 0 - > >>>> cpu16 1 623 > >>>> cpu17 1 623 > >>>> cpu18 1 623 > >>>> cpu19 1 623 > >>>> cpu20 0 - > >>>> cpu21 0 - > >>>> cpu22 0 - > >>>> cpu23 0 - > >>>> > >>>> Previously: > >>>> cpu online capacity > >>>> cpu0 1 1009 > >>>> cpu1 0 - > >>>> cpu2 1 1009 > >>>> cpu3 0 - > >>>> cpu4 1 1009 > >>>> cpu5 0 - > >>>> cpu6 1 1009 > >>>> cpu7 0 - > >>>> cpu8 1 1024 > >>>> cpu9 0 - > >>>> cpu10 1 1024 > >>>> cpu11 0 - > >>>> cpu12 1 1009 > >>>> cpu13 0 - > >>>> cpu14 1 1009 > >>>> cpu15 0 - > >>>> cpu16 1 623 > >>>> cpu17 1 623 > >>>> cpu18 1 623 > >>>> cpu19 1 623 > >>>> cpu20 1 623 > >>>> cpu21 1 623 > >>>> cpu22 1 623 > >>>> cpu23 1 623 > >>>> > >>>> Signed-off-by: Christian Loehle <christian.loehle@arm.com> > >>>> --- > >>>> Rafael, I don't immediately see how to fix this properly so I won't > >>>> try to, feel free to treat this as a bug report. > >>> > >>> Sure, thanks for reporting this! > >>> > >>> Well, I think that cpuhp_smt_enable() is missing a check. It looks to > >>> me like it should do the topology_is_primary_thread(cpu) check like > >>> cpuhp_smt_disable(). > >>> > >>> I'll cut a test patch for this later. > >> > >> Something like the attached one, perhaps. I haven't tested it yet, > >> but I'll do that later. > > > > Works here AFAICS, but my test system is not hybrid. > > Yep, on my end as well, thanks! > Tested-by: Christian Loehle <christian.loehle@arm.com> Thanks for testing and let me submit a proper patch.
© 2016 - 2025 Red Hat, Inc.