atomic add精度溢出
分析结果
如果info.txt中给出如下结论,说明是精度溢出导致的AI Core error。
Analysis result: success. "**********************Root cause conclusion******************" "dha status 1" found in log. It means Atomic accumulation exception, please check the input data and network accuracy. Attention please, if multiple tasks are running on the same device at the same time, false positives may be generated. You are advised to pull up only one task and collect it .
在Device的slog日志(report/*/slog/dev-os-id/[run|debug]/device-os/device-os_*.log)中,检查是否出现"Vm fault failed"关键字,如果没有出现,则确定是atomic精度溢出问题导致的AI Core Error问题;如果出现,则说明是内存越界问题,不是atomic精度溢出。alog日志示例如下:
2024-02-20-17-07-25/slog/dev-os-0/debug/device-os/device-os_20240122045443091.log:461:[EVENT] KERNEL(4128,sklogd):2024-01-22-05:03:02.259.649 [klogd.c:253][2572550.901383] [ascend] [ERROR] [devmm] [devmm_svm_device_fault 438] <kworker/u16:186:9871,9871> Vm fault failed. (hostpid=1885445; devid=0; vfid=0; ret=64; fault_addr=0x1240f1fa0000; start=0x1240f1fa0000)
Atlas A2训练系列产品/Atlas 800I A2推理产品上,由于硬件优化,不会出现atomic add精度溢出问题。
故障根因
出现该问题,是由于在算子运算过程中,有极端的数据遇到了atomic累加指令,atomic累加时如果出现溢出,则会报0x800000错误。
父主题: 典型问题案例