| Message ID | 20230804124549.2562977-2-zhengyejian1@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tracing: Fix cpu buffers unavailable problem and add its testcase | expand |
Hi Zheng, kernel test robot noticed the following build errors: [auto build test ERROR on linus/master] [cannot apply to rostedt-trace/for-next-urgent] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Zheng-Yejian/tracing-Fix-cpu-buffers-unavailable-due-to-record_disabled-messed/20230804-204751 base: linus/master patch link: https://lore.kernel.org/r/20230804124549.2562977-2-zhengyejian1%40huawei.com patch subject: [PATCH 1/2] tracing: Fix cpu buffers unavailable due to 'record_disabled' messed config: i386-randconfig-r025-20230731 (https://download.01.org/0day-ci/archive/20230805/202308050048.bUnVeBjV-lkp@intel.com/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce: (https://download.01.org/0day-ci/archive/20230805/202308050048.bUnVeBjV-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202308050048.bUnVeBjV-lkp@intel.com/ All errors (new ones prefixed by >>): >> kernel/trace/trace.c:5280:39: error: no member named 'max_buffer' in 'struct trace_array' ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); ~~ ^ kernel/trace/trace.c:5286:38: error: no member named 'max_buffer' in 'struct trace_array' ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); ~~ ^ 2 errors generated. vim +5280 kernel/trace/trace.c 5260 5261 int tracing_set_cpumask(struct trace_array *tr, 5262 cpumask_var_t tracing_cpumask_new) 5263 { 5264 int cpu; 5265 5266 if (!tr) 5267 return -EINVAL; 5268 5269 local_irq_disable(); 5270 arch_spin_lock(&tr->max_lock); 5271 for_each_tracing_cpu(cpu) { 5272 /* 5273 * Increase/decrease the disabled counter if we are 5274 * about to flip a bit in the cpumask: 5275 */ 5276 if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && 5277 !cpumask_test_cpu(cpu, tracing_cpumask_new)) { 5278 atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); 5279 ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); > 5280 ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); 5281 } 5282 if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && 5283 cpumask_test_cpu(cpu, tracing_cpumask_new)) { 5284 atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); 5285 ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); 5286 ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); 5287 } 5288 } 5289 arch_spin_unlock(&tr->max_lock); 5290 local_irq_enable(); 5291 5292 cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); 5293 5294 return 0; 5295 } 5296
On Sat, 5 Aug 2023 00:41:13 +0800 kernel test robot <lkp@intel.com> wrote: > 5276 if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && > 5277 !cpumask_test_cpu(cpu, tracing_cpumask_new)) { > 5278 atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); > 5279 ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); > > 5280 ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); The access to max_buffer requires a: #ifdef CONFIG_TRACER_MAX_TRACE Around them. -- Steve > 5281 } > 5282 if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && > 5283 cpumask_test_cpu(cpu, tracing_cpumask_new)) { > 5284 atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); > 5285 ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); > 5286 ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); > 5287 } > 5288 } > 5289 arch_spin_unlock(&tr->max_lock);
Hi Zheng, kernel test robot noticed the following build errors: [auto build test ERROR on linus/master] [also build test ERROR on rostedt-trace/for-next v6.5-rc4 next-20230804] [cannot apply to rostedt-trace/for-next-urgent] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Zheng-Yejian/tracing-Fix-cpu-buffers-unavailable-due-to-record_disabled-messed/20230804-204751 base: linus/master patch link: https://lore.kernel.org/r/20230804124549.2562977-2-zhengyejian1%40huawei.com patch subject: [PATCH 1/2] tracing: Fix cpu buffers unavailable due to 'record_disabled' messed config: i386-defconfig (https://download.01.org/0day-ci/archive/20230805/202308050601.nsx7Z4CY-lkp@intel.com/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce: (https://download.01.org/0day-ci/archive/20230805/202308050601.nsx7Z4CY-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202308050601.nsx7Z4CY-lkp@intel.com/ All errors (new ones prefixed by >>): kernel/trace/trace.c: In function 'tracing_set_cpumask': >> kernel/trace/trace.c:5280:60: error: 'struct trace_array' has no member named 'max_buffer'; did you mean 'array_buffer'? 5280 | ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); | ^~~~~~~~~~ | array_buffer kernel/trace/trace.c:5286:59: error: 'struct trace_array' has no member named 'max_buffer'; did you mean 'array_buffer'? 5286 | ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); | ^~~~~~~~~~ | array_buffer vim +5280 kernel/trace/trace.c 5260 5261 int tracing_set_cpumask(struct trace_array *tr, 5262 cpumask_var_t tracing_cpumask_new) 5263 { 5264 int cpu; 5265 5266 if (!tr) 5267 return -EINVAL; 5268 5269 local_irq_disable(); 5270 arch_spin_lock(&tr->max_lock); 5271 for_each_tracing_cpu(cpu) { 5272 /* 5273 * Increase/decrease the disabled counter if we are 5274 * about to flip a bit in the cpumask: 5275 */ 5276 if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && 5277 !cpumask_test_cpu(cpu, tracing_cpumask_new)) { 5278 atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); 5279 ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); > 5280 ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); 5281 } 5282 if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && 5283 cpumask_test_cpu(cpu, tracing_cpumask_new)) { 5284 atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); 5285 ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); 5286 ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); 5287 } 5288 } 5289 arch_spin_unlock(&tr->max_lock); 5290 local_irq_enable(); 5291 5292 cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); 5293 5294 return 0; 5295 } 5296
Hi Zheng, kernel test robot noticed the following build errors: [auto build test ERROR on linus/master] [also build test ERROR on rostedt-trace/for-next v6.5-rc4 next-20230804] [cannot apply to rostedt-trace/for-next-urgent] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Zheng-Yejian/tracing-Fix-cpu-buffers-unavailable-due-to-record_disabled-messed/20230804-204751 base: linus/master patch link: https://lore.kernel.org/r/20230804124549.2562977-2-zhengyejian1%40huawei.com patch subject: [PATCH 1/2] tracing: Fix cpu buffers unavailable due to 'record_disabled' messed config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20230805/202308050731.PQutr3r0-lkp@intel.com/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce: (https://download.01.org/0day-ci/archive/20230805/202308050731.PQutr3r0-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202308050731.PQutr3r0-lkp@intel.com/ All errors (new ones prefixed by >>): kernel/trace/trace.c: In function 'tracing_set_cpumask': >> kernel/trace/trace.c:5280:60: error: 'struct trace_array' has no member named 'max_buffer'; did you mean 'array_buffer'? 5280 | ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); | ^~~~~~~~~~ | array_buffer kernel/trace/trace.c:5286:59: error: 'struct trace_array' has no member named 'max_buffer'; did you mean 'array_buffer'? 5286 | ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); | ^~~~~~~~~~ | array_buffer vim +5280 kernel/trace/trace.c 5260 5261 int tracing_set_cpumask(struct trace_array *tr, 5262 cpumask_var_t tracing_cpumask_new) 5263 { 5264 int cpu; 5265 5266 if (!tr) 5267 return -EINVAL; 5268 5269 local_irq_disable(); 5270 arch_spin_lock(&tr->max_lock); 5271 for_each_tracing_cpu(cpu) { 5272 /* 5273 * Increase/decrease the disabled counter if we are 5274 * about to flip a bit in the cpumask: 5275 */ 5276 if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && 5277 !cpumask_test_cpu(cpu, tracing_cpumask_new)) { 5278 atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); 5279 ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); > 5280 ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); 5281 } 5282 if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && 5283 cpumask_test_cpu(cpu, tracing_cpumask_new)) { 5284 atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); 5285 ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); 5286 ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); 5287 } 5288 } 5289 arch_spin_unlock(&tr->max_lock); 5290 local_irq_enable(); 5291 5292 cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); 5293 5294 return 0; 5295 } 5296
On 2023/8/5 09:15, kernel test robot wrote: > Hi Zheng, > > kernel test robot noticed the following build errors: > > [auto build test ERROR on linus/master] > [also build test ERROR on rostedt-trace/for-next v6.5-rc4 next-20230804] > [cannot apply to rostedt-trace/for-next-urgent] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Zheng-Yejian/tracing-Fix-cpu-buffers-unavailable-due-to-record_disabled-messed/20230804-204751 > base: linus/master > patch link: https://lore.kernel.org/r/20230804124549.2562977-2-zhengyejian1%40huawei.com > patch subject: [PATCH 1/2] tracing: Fix cpu buffers unavailable due to 'record_disabled' messed > config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20230805/202308050731.PQutr3r0-lkp@intel.com/config) > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 > reproduce: (https://download.01.org/0day-ci/archive/20230805/202308050731.PQutr3r0-lkp@intel.com/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@intel.com> > | Closes: https://lore.kernel.org/oe-kbuild-all/202308050731.PQutr3r0-lkp@intel.com/ > > All errors (new ones prefixed by >>): > > kernel/trace/trace.c: In function 'tracing_set_cpumask': >>> kernel/trace/trace.c:5280:60: error: 'struct trace_array' has no member named 'max_buffer'; did you mean 'array_buffer'? > 5280 | ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); > | ^~~~~~~~~~ > | array_buffer > kernel/trace/trace.c:5286:59: error: 'struct trace_array' has no member named 'max_buffer'; did you mean 'array_buffer'? > 5286 | ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); > | ^~~~~~~~~~ > | array_buffer > Thank you, robot! I'll fix it in v2 soon. > > vim +5280 kernel/trace/trace.c > > 5260 > 5261 int tracing_set_cpumask(struct trace_array *tr, > 5262 cpumask_var_t tracing_cpumask_new) > 5263 { > 5264 int cpu; > 5265 > 5266 if (!tr) > 5267 return -EINVAL; > 5268 > 5269 local_irq_disable(); > 5270 arch_spin_lock(&tr->max_lock); > 5271 for_each_tracing_cpu(cpu) { > 5272 /* > 5273 * Increase/decrease the disabled counter if we are > 5274 * about to flip a bit in the cpumask: > 5275 */ > 5276 if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && > 5277 !cpumask_test_cpu(cpu, tracing_cpumask_new)) { > 5278 atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); > 5279 ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); >> 5280 ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); > 5281 } > 5282 if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && > 5283 cpumask_test_cpu(cpu, tracing_cpumask_new)) { > 5284 atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); > 5285 ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); > 5286 ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); > 5287 } > 5288 } > 5289 arch_spin_unlock(&tr->max_lock); > 5290 local_irq_enable(); > 5291 > 5292 cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); > 5293 > 5294 return 0; > 5295 } > 5296 >
On 2023/8/5 00:51, Steven Rostedt wrote: > On Sat, 5 Aug 2023 00:41:13 +0800 > kernel test robot <lkp@intel.com> wrote: > >> 5276 if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && >> 5277 !cpumask_test_cpu(cpu, tracing_cpumask_new)) { >> 5278 atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); >> 5279 ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); >>> 5280 ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); > > The access to max_buffer requires a: > > #ifdef CONFIG_TRACER_MAX_TRACE > > Around them. > > -- Steve Thanks, Steve, I'll add it in v2. -- Zheng Yejian > >> 5281 } >> 5282 if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && >> 5283 cpumask_test_cpu(cpu, tracing_cpumask_new)) { >> 5284 atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); >> 5285 ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); >> 5286 ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); >> 5287 } >> 5288 } >> 5289 arch_spin_unlock(&tr->max_lock); >
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b8870078ef58..691ec4d4cd19 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5277,11 +5277,13 @@ int tracing_set_cpumask(struct trace_array *tr, !cpumask_test_cpu(cpu, tracing_cpumask_new)) { atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); + ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu); } if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && cpumask_test_cpu(cpu, tracing_cpumask_new)) { atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); + ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu); } } arch_spin_unlock(&tr->max_lock);
Trace ring buffer can no longer record anything after executing like: # cd /sys/kernel/tracing # cat tracing_cpumask fff # echo 0 > tracing_cpumask # echo 1 > snapshot # echo fff > tracing_cpumask # echo "hello world" > trace_marker -bash: echo: write error: Bad file descriptor The root cause is that: 1. After `echo 0 > tracing_cpumask`, 'record_disabled' of cpu buffers in 'tr->array_buffer.buffer' became 1 (see tracing_set_cpumask()); 2. After `echo 1 > snapshot`, 'tr->array_buffer.buffer' is swapped with 'tr->max_buffer.buffer', then the 'record_disabled' became 0 (see update_max_tr()); 3. After `echo fff > tracing_cpumask`, the 'record_disabled' become -1; Then array_buffer and max_buffer are both unavailable due to value of 'record_disabled' is not 0. To fix it, enable or disable both array_buffer and max_buffer at the same time in tracing_set_cpumask(). Fixes: 71babb2705e2 ("tracing: change CPU ring buffer state from tracing_cpumask") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> --- kernel/trace/trace.c | 2 ++ 1 file changed, 2 insertions(+)