嵌入式Linux中SPI中断日志高频输出问题的排查与解决

问题背景 #

搭载嵌入式Linux系统的SOC通过SPI协议与另一芯片通信，监控/var/log/kern.log时发现高频输出特定日志，导致系统空闲内存骤降。

高频日志内容 #

日志片段如下：

2022-11-09T15:28:38.827661+00:00 mcu-v1 kernel: [  513.748802] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.827758+00:00 mcu-v1 kernel: [  513.748855] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.838743+00:00 mcu-v1 kernel: [  513.759301] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.838843+00:00 mcu-v1 kernel: [  513.759347] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.838885+00:00 mcu-v1 kernel: [  513.759418] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.838921+00:00 mcu-v1 kernel: [  513.759457] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.850540+00:00 mcu-v1 kernel: [  513.769821] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.850703+00:00 mcu-v1 kernel: [  513.769862] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.850753+00:00 mcu-v1 kernel: [  513.769960] fsl_spi e0007000.spi: fsl_spi_irq: events 300
2022-11-09T15:28:38.850788+00:00 mcu-v1 kernel: [  513.770003] fsl_spi e0007000.spi: fsl_spi_irq: events 300

已尝试操作 #

• 在内核命令行设置log_level=2以屏蔽该日志，但日志仍持续输出
• 查阅4.14版本内核源码未找到原因

待解决问题 #

1. 该日志的具体含义是什么？
2. 如何解决日志高频输出导致内存骤降的问题？

内容的提问来源于stack exchange，提问作者Moh3N