* [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create()
@ 2025-04-07 6:32 Anand Moon
2025-04-17 13:20 ` Will Deacon
2025-05-09 13:55 ` Will Deacon
0 siblings, 2 replies; 4+ messages in thread
From: Anand Moon @ 2025-04-07 6:32 UTC (permalink / raw)
To: Jiucheng Xu, Will Deacon, Mark Rutland, Neil Armstrong,
Kevin Hilman, Jerome Brunet, Martin Blumenstingl,
open list:AMLOGIC DDR PMU DRIVER,
moderated list:ARM PMU PROFILING AND DEBUGGING,
open list:ARM PMU PROFILING AND DEBUGGING, open list
Cc: Anand Moon
The Amlogic DDR PMU driver meson_ddr_pmu_create() function incorrectly uses
smp_processor_id(), which assumes disabled preemption. This leads to kernel
warnings during module loading because meson_ddr_pmu_create() can be called
in a preemptible context.
Following kernel warning and stack trace:
[ 31.745138] [ T2289] BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/2289
[ 31.745154] [ T2289] caller is debug_smp_processor_id+0x28/0x38
[ 31.745172] [ T2289] CPU: 4 UID: 0 PID: 2289 Comm: (udev-worker) Tainted: GW 6.14.0-0-MANJARO-ARM #1 59519addcbca6ba8de735e151fd7b9e97aac7ff0
[ 31.745181] [ T2289] Tainted: [W]=WARN
[ 31.745183] [ T2289] Hardware name: Hardkernel ODROID-N2Plus (DT)
[ 31.745188] [ T2289] Call trace:
[ 31.745191] [ T2289] show_stack+0x28/0x40 (C)
[ 31.745199] [ T2289] dump_stack_lvl+0x4c/0x198
[ 31.745205] [ T2289] dump_stack+0x20/0x50
[ 31.745209] [ T2289] check_preemption_disabled+0xec/0xf0
[ 31.745213] [ T2289] debug_smp_processor_id+0x28/0x38
[ 31.745216] [ T2289] meson_ddr_pmu_create+0x200/0x560 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
[ 31.745237] [ T2289] g12_ddr_pmu_probe+0x20/0x38 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
[ 31.745246] [ T2289] platform_probe+0x98/0xe0
[ 31.745254] [ T2289] really_probe+0x144/0x3f8
[ 31.745258] [ T2289] __driver_probe_device+0xb8/0x180
[ 31.745261] [ T2289] driver_probe_device+0x54/0x268
[ 31.745264] [ T2289] __driver_attach+0x11c/0x288
[ 31.745267] [ T2289] bus_for_each_dev+0xfc/0x160
[ 31.745274] [ T2289] driver_attach+0x34/0x50
[ 31.745277] [ T2289] bus_add_driver+0x160/0x2b0
[ 31.745281] [ T2289] driver_register+0x78/0x120
[ 31.745285] [ T2289] __platform_driver_register+0x30/0x48
[ 31.745288] [ T2289] init_module+0x30/0xfe0 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
[ 31.745298] [ T2289] do_one_initcall+0x11c/0x438
[ 31.745303] [ T2289] do_init_module+0x68/0x228
[ 31.745311] [ T2289] load_module+0x118c/0x13a8
[ 31.745315] [ T2289] __arm64_sys_finit_module+0x274/0x390
[ 31.745320] [ T2289] invoke_syscall+0x74/0x108
[ 31.745326] [ T2289] el0_svc_common+0x90/0xf8
[ 31.745330] [ T2289] do_el0_svc+0x2c/0x48
[ 31.745333] [ T2289] el0_svc+0x60/0x150
[ 31.745337] [ T2289] el0t_64_sync_handler+0x80/0x118
[ 31.745341] [ T2289] el0t_64_sync+0x1b8/0x1c0
Changes replaces smp_processor_id() with raw_smp_processor_id() to
ensure safe CPU ID retrieval in preemptible contexts.
Cc: Jiucheng Xu <jiucheng.xu@amlogic.com>
Fixes: 2016e2113d35 ("perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver")
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
---
drivers/perf/amlogic/meson_ddr_pmu_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/perf/amlogic/meson_ddr_pmu_core.c b/drivers/perf/amlogic/meson_ddr_pmu_core.c
index 07446d784a1a..c1e755c356a3 100644
--- a/drivers/perf/amlogic/meson_ddr_pmu_core.c
+++ b/drivers/perf/amlogic/meson_ddr_pmu_core.c
@@ -511,7 +511,7 @@ int meson_ddr_pmu_create(struct platform_device *pdev)
fmt_attr_fill(pmu->info.hw_info->fmt_attr);
- pmu->cpu = smp_processor_id();
+ pmu->cpu = raw_smp_processor_id();
name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME);
if (!name)
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
--
2.49.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create()
2025-04-07 6:32 [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create() Anand Moon
@ 2025-04-17 13:20 ` Will Deacon
2025-04-17 15:17 ` Robin Murphy
2025-05-09 13:55 ` Will Deacon
1 sibling, 1 reply; 4+ messages in thread
From: Will Deacon @ 2025-04-17 13:20 UTC (permalink / raw)
To: Anand Moon, robin.murphy
Cc: Jiucheng Xu, Mark Rutland, Neil Armstrong, Kevin Hilman,
Jerome Brunet, Martin Blumenstingl,
open list:AMLOGIC DDR PMU DRIVER,
moderated list:ARM PMU PROFILING AND DEBUGGING,
open list:ARM PMU PROFILING AND DEBUGGING, open list
On Mon, Apr 07, 2025 at 12:02:03PM +0530, Anand Moon wrote:
> The Amlogic DDR PMU driver meson_ddr_pmu_create() function incorrectly uses
> smp_processor_id(), which assumes disabled preemption. This leads to kernel
> warnings during module loading because meson_ddr_pmu_create() can be called
> in a preemptible context.
>
> Following kernel warning and stack trace:
> [ 31.745138] [ T2289] BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/2289
> [ 31.745154] [ T2289] caller is debug_smp_processor_id+0x28/0x38
> [ 31.745172] [ T2289] CPU: 4 UID: 0 PID: 2289 Comm: (udev-worker) Tainted: GW 6.14.0-0-MANJARO-ARM #1 59519addcbca6ba8de735e151fd7b9e97aac7ff0
> [ 31.745181] [ T2289] Tainted: [W]=WARN
> [ 31.745183] [ T2289] Hardware name: Hardkernel ODROID-N2Plus (DT)
> [ 31.745188] [ T2289] Call trace:
> [ 31.745191] [ T2289] show_stack+0x28/0x40 (C)
> [ 31.745199] [ T2289] dump_stack_lvl+0x4c/0x198
> [ 31.745205] [ T2289] dump_stack+0x20/0x50
> [ 31.745209] [ T2289] check_preemption_disabled+0xec/0xf0
> [ 31.745213] [ T2289] debug_smp_processor_id+0x28/0x38
> [ 31.745216] [ T2289] meson_ddr_pmu_create+0x200/0x560 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
> [ 31.745237] [ T2289] g12_ddr_pmu_probe+0x20/0x38 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
> [ 31.745246] [ T2289] platform_probe+0x98/0xe0
> [ 31.745254] [ T2289] really_probe+0x144/0x3f8
> [ 31.745258] [ T2289] __driver_probe_device+0xb8/0x180
> [ 31.745261] [ T2289] driver_probe_device+0x54/0x268
> [ 31.745264] [ T2289] __driver_attach+0x11c/0x288
> [ 31.745267] [ T2289] bus_for_each_dev+0xfc/0x160
> [ 31.745274] [ T2289] driver_attach+0x34/0x50
> [ 31.745277] [ T2289] bus_add_driver+0x160/0x2b0
> [ 31.745281] [ T2289] driver_register+0x78/0x120
> [ 31.745285] [ T2289] __platform_driver_register+0x30/0x48
> [ 31.745288] [ T2289] init_module+0x30/0xfe0 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
> [ 31.745298] [ T2289] do_one_initcall+0x11c/0x438
> [ 31.745303] [ T2289] do_init_module+0x68/0x228
> [ 31.745311] [ T2289] load_module+0x118c/0x13a8
> [ 31.745315] [ T2289] __arm64_sys_finit_module+0x274/0x390
> [ 31.745320] [ T2289] invoke_syscall+0x74/0x108
> [ 31.745326] [ T2289] el0_svc_common+0x90/0xf8
> [ 31.745330] [ T2289] do_el0_svc+0x2c/0x48
> [ 31.745333] [ T2289] el0_svc+0x60/0x150
> [ 31.745337] [ T2289] el0t_64_sync_handler+0x80/0x118
> [ 31.745341] [ T2289] el0t_64_sync+0x1b8/0x1c0
>
> Changes replaces smp_processor_id() with raw_smp_processor_id() to
> ensure safe CPU ID retrieval in preemptible contexts.
>
> Cc: Jiucheng Xu <jiucheng.xu@amlogic.com>
> Fixes: 2016e2113d35 ("perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver")
> Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> ---
> drivers/perf/amlogic/meson_ddr_pmu_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/perf/amlogic/meson_ddr_pmu_core.c b/drivers/perf/amlogic/meson_ddr_pmu_core.c
> index 07446d784a1a..c1e755c356a3 100644
> --- a/drivers/perf/amlogic/meson_ddr_pmu_core.c
> +++ b/drivers/perf/amlogic/meson_ddr_pmu_core.c
> @@ -511,7 +511,7 @@ int meson_ddr_pmu_create(struct platform_device *pdev)
>
> fmt_attr_fill(pmu->info.hw_info->fmt_attr);
>
> - pmu->cpu = smp_processor_id();
> + pmu->cpu = raw_smp_processor_id();
>
> name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME);
> if (!name)
Bah, this follows what the other drivers are doing but I continue to
dislike the races we have between CPU hotplug and perf PMU registration.
Robin -- did you have a crack at fixing that or did I dream it?
Will
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create()
2025-04-17 13:20 ` Will Deacon
@ 2025-04-17 15:17 ` Robin Murphy
0 siblings, 0 replies; 4+ messages in thread
From: Robin Murphy @ 2025-04-17 15:17 UTC (permalink / raw)
To: Will Deacon, Anand Moon
Cc: Jiucheng Xu, Mark Rutland, Neil Armstrong, Kevin Hilman,
Jerome Brunet, Martin Blumenstingl,
open list:AMLOGIC DDR PMU DRIVER,
moderated list:ARM PMU PROFILING AND DEBUGGING,
open list:ARM PMU PROFILING AND DEBUGGING, open list
On 17/04/2025 2:20 pm, Will Deacon wrote:
> On Mon, Apr 07, 2025 at 12:02:03PM +0530, Anand Moon wrote:
>> The Amlogic DDR PMU driver meson_ddr_pmu_create() function incorrectly uses
>> smp_processor_id(), which assumes disabled preemption. This leads to kernel
>> warnings during module loading because meson_ddr_pmu_create() can be called
>> in a preemptible context.
>>
>> Following kernel warning and stack trace:
>> [ 31.745138] [ T2289] BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/2289
>> [ 31.745154] [ T2289] caller is debug_smp_processor_id+0x28/0x38
>> [ 31.745172] [ T2289] CPU: 4 UID: 0 PID: 2289 Comm: (udev-worker) Tainted: GW 6.14.0-0-MANJARO-ARM #1 59519addcbca6ba8de735e151fd7b9e97aac7ff0
>> [ 31.745181] [ T2289] Tainted: [W]=WARN
>> [ 31.745183] [ T2289] Hardware name: Hardkernel ODROID-N2Plus (DT)
>> [ 31.745188] [ T2289] Call trace:
>> [ 31.745191] [ T2289] show_stack+0x28/0x40 (C)
>> [ 31.745199] [ T2289] dump_stack_lvl+0x4c/0x198
>> [ 31.745205] [ T2289] dump_stack+0x20/0x50
>> [ 31.745209] [ T2289] check_preemption_disabled+0xec/0xf0
>> [ 31.745213] [ T2289] debug_smp_processor_id+0x28/0x38
>> [ 31.745216] [ T2289] meson_ddr_pmu_create+0x200/0x560 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
>> [ 31.745237] [ T2289] g12_ddr_pmu_probe+0x20/0x38 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
>> [ 31.745246] [ T2289] platform_probe+0x98/0xe0
>> [ 31.745254] [ T2289] really_probe+0x144/0x3f8
>> [ 31.745258] [ T2289] __driver_probe_device+0xb8/0x180
>> [ 31.745261] [ T2289] driver_probe_device+0x54/0x268
>> [ 31.745264] [ T2289] __driver_attach+0x11c/0x288
>> [ 31.745267] [ T2289] bus_for_each_dev+0xfc/0x160
>> [ 31.745274] [ T2289] driver_attach+0x34/0x50
>> [ 31.745277] [ T2289] bus_add_driver+0x160/0x2b0
>> [ 31.745281] [ T2289] driver_register+0x78/0x120
>> [ 31.745285] [ T2289] __platform_driver_register+0x30/0x48
>> [ 31.745288] [ T2289] init_module+0x30/0xfe0 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
>> [ 31.745298] [ T2289] do_one_initcall+0x11c/0x438
>> [ 31.745303] [ T2289] do_init_module+0x68/0x228
>> [ 31.745311] [ T2289] load_module+0x118c/0x13a8
>> [ 31.745315] [ T2289] __arm64_sys_finit_module+0x274/0x390
>> [ 31.745320] [ T2289] invoke_syscall+0x74/0x108
>> [ 31.745326] [ T2289] el0_svc_common+0x90/0xf8
>> [ 31.745330] [ T2289] do_el0_svc+0x2c/0x48
>> [ 31.745333] [ T2289] el0_svc+0x60/0x150
>> [ 31.745337] [ T2289] el0t_64_sync_handler+0x80/0x118
>> [ 31.745341] [ T2289] el0t_64_sync+0x1b8/0x1c0
>>
>> Changes replaces smp_processor_id() with raw_smp_processor_id() to
>> ensure safe CPU ID retrieval in preemptible contexts.
>>
>> Cc: Jiucheng Xu <jiucheng.xu@amlogic.com>
>> Fixes: 2016e2113d35 ("perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver")
>> Signed-off-by: Anand Moon <linux.amoon@gmail.com>
>> ---
>> drivers/perf/amlogic/meson_ddr_pmu_core.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/perf/amlogic/meson_ddr_pmu_core.c b/drivers/perf/amlogic/meson_ddr_pmu_core.c
>> index 07446d784a1a..c1e755c356a3 100644
>> --- a/drivers/perf/amlogic/meson_ddr_pmu_core.c
>> +++ b/drivers/perf/amlogic/meson_ddr_pmu_core.c
>> @@ -511,7 +511,7 @@ int meson_ddr_pmu_create(struct platform_device *pdev)
>>
>> fmt_attr_fill(pmu->info.hw_info->fmt_attr);
>>
>> - pmu->cpu = smp_processor_id();
>> + pmu->cpu = raw_smp_processor_id();
>>
>> name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME);
>> if (!name)
>
>
> Bah, this follows what the other drivers are doing but I continue to
> dislike the races we have between CPU hotplug and perf PMU registration.
>
> Robin -- did you have a crack at fixing that or did I dream it?
I've had "Perf core should do cpu hotplug!" written on the whiteboard
behind my desk for about 5 years now, does that count? :)
However my initial plan was to at least factor out some of this common
boilerplate within drivers/perf itself - I currently have one WIP patch
from last year making a start on that, but I reckon I can find a way to
make it crucial for the other PMU driver work I've already got scheduled
this quarter (assuming I win the game of whack-a-mole against IOMMU race
conditions soon enough...)
Cheers,
Robin.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create()
2025-04-07 6:32 [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create() Anand Moon
2025-04-17 13:20 ` Will Deacon
@ 2025-05-09 13:55 ` Will Deacon
1 sibling, 0 replies; 4+ messages in thread
From: Will Deacon @ 2025-05-09 13:55 UTC (permalink / raw)
To: Jiucheng Xu, Mark Rutland, Neil Armstrong, Kevin Hilman,
Jerome Brunet, Martin Blumenstingl, linux-amlogic,
linux-arm-kernel, linux-perf-users, linux-kernel, Anand Moon
Cc: catalin.marinas, kernel-team, Will Deacon
On Mon, 07 Apr 2025 12:02:03 +0530, Anand Moon wrote:
> The Amlogic DDR PMU driver meson_ddr_pmu_create() function incorrectly uses
> smp_processor_id(), which assumes disabled preemption. This leads to kernel
> warnings during module loading because meson_ddr_pmu_create() can be called
> in a preemptible context.
>
> Following kernel warning and stack trace:
> [ 31.745138] [ T2289] BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/2289
> [ 31.745154] [ T2289] caller is debug_smp_processor_id+0x28/0x38
> [ 31.745172] [ T2289] CPU: 4 UID: 0 PID: 2289 Comm: (udev-worker) Tainted: GW 6.14.0-0-MANJARO-ARM #1 59519addcbca6ba8de735e151fd7b9e97aac7ff0
> [ 31.745181] [ T2289] Tainted: [W]=WARN
> [ 31.745183] [ T2289] Hardware name: Hardkernel ODROID-N2Plus (DT)
> [ 31.745188] [ T2289] Call trace:
> [ 31.745191] [ T2289] show_stack+0x28/0x40 (C)
> [ 31.745199] [ T2289] dump_stack_lvl+0x4c/0x198
> [ 31.745205] [ T2289] dump_stack+0x20/0x50
> [ 31.745209] [ T2289] check_preemption_disabled+0xec/0xf0
> [ 31.745213] [ T2289] debug_smp_processor_id+0x28/0x38
> [ 31.745216] [ T2289] meson_ddr_pmu_create+0x200/0x560 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
> [ 31.745237] [ T2289] g12_ddr_pmu_probe+0x20/0x38 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
> [ 31.745246] [ T2289] platform_probe+0x98/0xe0
> [ 31.745254] [ T2289] really_probe+0x144/0x3f8
> [ 31.745258] [ T2289] __driver_probe_device+0xb8/0x180
> [ 31.745261] [ T2289] driver_probe_device+0x54/0x268
> [ 31.745264] [ T2289] __driver_attach+0x11c/0x288
> [ 31.745267] [ T2289] bus_for_each_dev+0xfc/0x160
> [ 31.745274] [ T2289] driver_attach+0x34/0x50
> [ 31.745277] [ T2289] bus_add_driver+0x160/0x2b0
> [ 31.745281] [ T2289] driver_register+0x78/0x120
> [ 31.745285] [ T2289] __platform_driver_register+0x30/0x48
> [ 31.745288] [ T2289] init_module+0x30/0xfe0 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd]
> [ 31.745298] [ T2289] do_one_initcall+0x11c/0x438
> [ 31.745303] [ T2289] do_init_module+0x68/0x228
> [ 31.745311] [ T2289] load_module+0x118c/0x13a8
> [ 31.745315] [ T2289] __arm64_sys_finit_module+0x274/0x390
> [ 31.745320] [ T2289] invoke_syscall+0x74/0x108
> [ 31.745326] [ T2289] el0_svc_common+0x90/0xf8
> [ 31.745330] [ T2289] do_el0_svc+0x2c/0x48
> [ 31.745333] [ T2289] el0_svc+0x60/0x150
> [ 31.745337] [ T2289] el0t_64_sync_handler+0x80/0x118
> [ 31.745341] [ T2289] el0t_64_sync+0x1b8/0x1c0
>
> [...]
Applied to will (for-next/perf), thanks!
[1/1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create()
https://git.kernel.org/will/c/097469a2b0f1
Hopefully we can fix this properly when Robin moves the hotplug logic
into perf core...
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-05-09 13:55 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2025-04-07 6:32 [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create() Anand Moon
2025-04-17 13:20 ` Will Deacon
2025-04-17 15:17 ` Robin Murphy
2025-05-09 13:55 ` Will Deacon
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