| Message ID | 1478172041-9067-1-git-send-email-kda@linux-powerpc.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
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.
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. > >
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++;
[ 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(-)