* [PATCH] ppc: cpufreq: Use get_cpu()/put_cpu() instead of smp_processor_id() to avoid the oops
@ 2016-11-03 11:20 Denis Kirjanov
2016-11-03 14:43 ` Gautham R Shenoy
0 siblings, 1 reply; 3+ messages in thread
From: Denis Kirjanov @ 2016-11-03 11:20 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Denis Kirjanov
[ 67.700897] BUG: using smp_processor_id() in preemptible [00000000] code: cat/7343
[ 67.700988] caller is .powernv_cpufreq_throttle_check+0x2c/0x710
[ 67.700998] CPU: 13 PID: 7343 Comm: cat Not tainted 4.8.0-rc5-dirty #1
[ 67.701038] Call Trace:
[ 67.701066] [c0000007d25b75b0] [c000000000971378] .dump_stack+0xe4/0x150 (unreliable)
[ 67.701153] [c0000007d25b7640] [c0000000005162e4] .check_preemption_disabled+0x134/0x150
[ 67.701238] [c0000007d25b76e0] [c0000000007b63ac] .powernv_cpufreq_throttle_check+0x2c/0x710
[ 67.701322] [c0000007d25b7790] [c0000000007b6d18] .powernv_cpufreq_target_index+0x288/0x360
[ 67.701407] [c0000007d25b7870] [c0000000007acee4] .__cpufreq_driver_target+0x394/0x8c0
[ 67.701491] [c0000007d25b7920] [c0000000007b22ac] .cpufreq_set+0x7c/0xd0
[ 67.701565] [c0000007d25b79b0] [c0000000007adf50] .store_scaling_setspeed+0x80/0xc0
[ 67.701650] [c0000007d25b7a40] [c0000000007ae270] .store+0xa0/0x100
[ 67.701723] [c0000007d25b7ae0] [c0000000003566e8] .sysfs_kf_write+0x88/0xb0
[ 67.701796] [c0000007d25b7b70] [c0000000003553b8] .kernfs_fop_write+0x178/0x260
[ 67.701881] [c0000007d25b7c10] [c0000000002ac3cc] .__vfs_write+0x3c/0x1c0
[ 67.701954] [c0000007d25b7cf0] [c0000000002ad584] .vfs_write+0xc4/0x230
[ 67.702027] [c0000007d25b7d90] [c0000000002aeef8] .SyS_write+0x58/0x100
[ 67.702101] [c0000007d25b7e30] [c00000000000bfec] system_call+0x38/0xfc
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
---
drivers/cpufreq/powernv-cpufreq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index d3ffde8..4cd91a3 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -475,7 +475,7 @@ static inline unsigned int get_nominal_index(void)
static void powernv_cpufreq_throttle_check(void *data)
{
struct chip *chip;
- unsigned int cpu = smp_processor_id();
+ int cpu;
unsigned long pmsr;
int pmsr_pmax;
unsigned int pmsr_pmax_idx;
@@ -491,9 +491,11 @@ static void powernv_cpufreq_throttle_check(void *data)
goto next;
chip->throttled = true;
if (pmsr_pmax_idx > powernv_pstate_info.nominal) {
+ cpu = get_cpu();
pr_warn_once("CPU %d on Chip %u has Pmax(%d) reduced below nominal frequency(%d)\n",
cpu, chip->id, pmsr_pmax,
idx_to_pstate(powernv_pstate_info.nominal));
+ put_cpu();
chip->throttle_sub_turbo++;
} else {
chip->throttle_turbo++;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ppc: cpufreq: Use get_cpu()/put_cpu() instead of smp_processor_id() to avoid the oops
2016-11-03 11:20 [PATCH] ppc: cpufreq: Use get_cpu()/put_cpu() instead of smp_processor_id() to avoid the oops Denis Kirjanov
@ 2016-11-03 14:43 ` Gautham R Shenoy
2016-11-03 14:56 ` Denis Kirjanov
0 siblings, 1 reply; 3+ messages in thread
From: Gautham R Shenoy @ 2016-11-03 14:43 UTC (permalink / raw)
To: Denis Kirjanov
Cc: linuxppc-dev, Shilpasri G Bhat, Akshay Adiga,
Vaidyanathan Srinivasan
Hi Denis,
On Thu, Nov 03, 2016 at 07:20:41AM -0400, Denis Kirjanov wrote:
> [ 67.700897] BUG: using smp_processor_id() in preemptible [00000000] code: cat/7343
> [ 67.700988] caller is .powernv_cpufreq_throttle_check+0x2c/0x710
> [ 67.700998] CPU: 13 PID: 7343 Comm: cat Not tainted 4.8.0-rc5-dirty #1
> [ 67.701038] Call Trace:
> [ 67.701066] [c0000007d25b75b0] [c000000000971378] .dump_stack+0xe4/0x150 (unreliable)
> [ 67.701153] [c0000007d25b7640] [c0000000005162e4] .check_preemption_disabled+0x134/0x150
> [ 67.701238] [c0000007d25b76e0] [c0000000007b63ac] .powernv_cpufreq_throttle_check+0x2c/0x710
> [ 67.701322] [c0000007d25b7790] [c0000000007b6d18] .powernv_cpufreq_target_index+0x288/0x360
> [ 67.701407] [c0000007d25b7870] [c0000000007acee4] .__cpufreq_driver_target+0x394/0x8c0
> [ 67.701491] [c0000007d25b7920] [c0000000007b22ac] .cpufreq_set+0x7c/0xd0
> [ 67.701565] [c0000007d25b79b0] [c0000000007adf50] .store_scaling_setspeed+0x80/0xc0
> [ 67.701650] [c0000007d25b7a40] [c0000000007ae270] .store+0xa0/0x100
> [ 67.701723] [c0000007d25b7ae0] [c0000000003566e8] .sysfs_kf_write+0x88/0xb0
> [ 67.701796] [c0000007d25b7b70] [c0000000003553b8] .kernfs_fop_write+0x178/0x260
> [ 67.701881] [c0000007d25b7c10] [c0000000002ac3cc] .__vfs_write+0x3c/0x1c0
> [ 67.701954] [c0000007d25b7cf0] [c0000000002ad584] .vfs_write+0xc4/0x230
> [ 67.702027] [c0000007d25b7d90] [c0000000002aeef8] .SyS_write+0x58/0x100
> [ 67.702101] [c0000007d25b7e30] [c00000000000bfec] system_call+0x38/0xfc
>
> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Thanks for looking into this!
> ---
> drivers/cpufreq/powernv-cpufreq.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index d3ffde8..4cd91a3 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -475,7 +475,7 @@ static inline unsigned int get_nominal_index(void)
> static void powernv_cpufreq_throttle_check(void *data)
The powernv_cpufreq_throttle_check() checks if the frequency on any of
the CPUs on this chip has been throttled. Hence it needs to be
executed without preemption on a CPU on the particular chip.
It is called in two places currently:
a) powernv_cpufreq_work_fn where
it is called via smp_call_function_any() which will ensure that the
function will be executed without preempted.
b) from powernv_cpufreq_target_index: Here it should be nested within
the preempt_disable() preempt_enable() calls. It currently is not.
So, I would suggest fixing b) instead of locally fixing
smp_processor_id() to get_cpu()/put_cpu().
> {
> struct chip *chip;
> - unsigned int cpu = smp_processor_id();
> + int cpu;
> unsigned long pmsr;
> int pmsr_pmax;
> unsigned int pmsr_pmax_idx;
> @@ -491,9 +491,11 @@ static void powernv_cpufreq_throttle_check(void *data)
> goto next;
> chip->throttled = true;
> if (pmsr_pmax_idx > powernv_pstate_info.nominal) {
> + cpu = get_cpu();
> pr_warn_once("CPU %d on Chip %u has Pmax(%d) reduced below nominal frequency(%d)\n",
> cpu, chip->id, pmsr_pmax,
> idx_to_pstate(powernv_pstate_info.nominal));
> + put_cpu();
> chip->throttle_sub_turbo++;
> } else {
> chip->throttle_turbo++;
> --
> 1.8.3.1
>
--
Thanks and Regards
gautham.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ppc: cpufreq: Use get_cpu()/put_cpu() instead of smp_processor_id() to avoid the oops
2016-11-03 14:43 ` Gautham R Shenoy
@ 2016-11-03 14:56 ` Denis Kirjanov
0 siblings, 0 replies; 3+ messages in thread
From: Denis Kirjanov @ 2016-11-03 14:56 UTC (permalink / raw)
To: ego@linux.vnet.ibm.com
Cc: Denis Kirjanov, linuxppc-dev@lists.ozlabs.org, Akshay Adiga,
Shilpasri G Bhat
[-- Attachment #1: Type: text/plain, Size: 4058 bytes --]
On Thursday, November 3, 2016, Gautham R Shenoy <ego@linux.vnet.ibm.com>
wrote:
> Hi Denis,
>
> On Thu, Nov 03, 2016 at 07:20:41AM -0400, Denis Kirjanov wrote:
> > [ 67.700897] BUG: using smp_processor_id() in preemptible [00000000]
> code: cat/7343
> > [ 67.700988] caller is .powernv_cpufreq_throttle_check+0x2c/0x710
> > [ 67.700998] CPU: 13 PID: 7343 Comm: cat Not tainted 4.8.0-rc5-dirty #1
> > [ 67.701038] Call Trace:
> > [ 67.701066] [c0000007d25b75b0] [c000000000971378]
> .dump_stack+0xe4/0x150 (unreliable)
> > [ 67.701153] [c0000007d25b7640] [c0000000005162e4]
> .check_preemption_disabled+0x134/0x150
> > [ 67.701238] [c0000007d25b76e0] [c0000000007b63ac]
> .powernv_cpufreq_throttle_check+0x2c/0x710
> > [ 67.701322] [c0000007d25b7790] [c0000000007b6d18]
> .powernv_cpufreq_target_index+0x288/0x360
> > [ 67.701407] [c0000007d25b7870] [c0000000007acee4]
> .__cpufreq_driver_target+0x394/0x8c0
> > [ 67.701491] [c0000007d25b7920] [c0000000007b22ac]
> .cpufreq_set+0x7c/0xd0
> > [ 67.701565] [c0000007d25b79b0] [c0000000007adf50]
> .store_scaling_setspeed+0x80/0xc0
> > [ 67.701650] [c0000007d25b7a40] [c0000000007ae270] .store+0xa0/0x100
> > [ 67.701723] [c0000007d25b7ae0] [c0000000003566e8]
> .sysfs_kf_write+0x88/0xb0
> > [ 67.701796] [c0000007d25b7b70] [c0000000003553b8]
> .kernfs_fop_write+0x178/0x260
> > [ 67.701881] [c0000007d25b7c10] [c0000000002ac3cc]
> .__vfs_write+0x3c/0x1c0
> > [ 67.701954] [c0000007d25b7cf0] [c0000000002ad584]
> .vfs_write+0xc4/0x230
> > [ 67.702027] [c0000007d25b7d90] [c0000000002aeef8]
> .SyS_write+0x58/0x100
> > [ 67.702101] [c0000007d25b7e30] [c00000000000bfec]
> system_call+0x38/0xfc
> >
> > Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org <javascript:;>>
>
>
> Thanks for looking into this!
> > ---
> > drivers/cpufreq/powernv-cpufreq.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/cpufreq/powernv-cpufreq.c
> b/drivers/cpufreq/powernv-cpufreq.c
> > index d3ffde8..4cd91a3 100644
> > --- a/drivers/cpufreq/powernv-cpufreq.c
> > +++ b/drivers/cpufreq/powernv-cpufreq.c
> > @@ -475,7 +475,7 @@ static inline unsigned int get_nominal_index(void)
> > static void powernv_cpufreq_throttle_check(void *data)
>
> The powernv_cpufreq_throttle_check() checks if the frequency on any of
> the CPUs on this chip has been throttled. Hence it needs to be
> executed without preemption on a CPU on the particular chip.
>
> It is called in two places currently:
>
> a) powernv_cpufreq_work_fn where
> it is called via smp_call_function_any() which will ensure that the
> function will be executed without preempted.
>
> b) from powernv_cpufreq_target_index: Here it should be nested within
> the preempt_disable() preempt_enable() calls. It currently is not.
>
> So, I would suggest fixing b) instead of locally fixing
> smp_processor_id() to get_cpu()/put_cpu().
Ok, I'll send the v2 then.
Thanks!
>
> > {
> > struct chip *chip;
> > - unsigned int cpu = smp_processor_id();
> > + int cpu;
> > unsigned long pmsr;
> > int pmsr_pmax;
> > unsigned int pmsr_pmax_idx;
> > @@ -491,9 +491,11 @@ static void powernv_cpufreq_throttle_check(void
> *data)
> > goto next;
> > chip->throttled = true;
> > if (pmsr_pmax_idx > powernv_pstate_info.nominal) {
> > + cpu = get_cpu();
> > pr_warn_once("CPU %d on Chip %u has Pmax(%d)
> reduced below nominal frequency(%d)\n",
> > cpu, chip->id, pmsr_pmax,
> > idx_to_pstate(powernv_pstate_
> info.nominal));
> > + put_cpu();
> > chip->throttle_sub_turbo++;
> > } else {
> > chip->throttle_turbo++;
> > --
> > 1.8.3.1
> >
>
> --
> Thanks and Regards
> gautham.
>
>
--
Regards / Mit besten Grüßen,
Denis
[-- Attachment #2: Type: text/html, Size: 5053 bytes --]
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2016-11-03 11:20 [PATCH] ppc: cpufreq: Use get_cpu()/put_cpu() instead of smp_processor_id() to avoid the oops Denis Kirjanov
2016-11-03 14:43 ` Gautham R Shenoy
2016-11-03 14:56 ` Denis Kirjanov
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