On 2020-06-16 09:14:37 [+0200], Stephen Berman wrote: > > I set CONFIG_ACPI_DEBUG=y, applied the patch and rebuilt 5.6.4, but: > > $ cat /sys/kernel/debug/tracing/trace > trace.txt > cat: /sys/kernel/debug/tracing/trace: No such file or directory > > Here are all the 5.6.4 config options with "TRACING" or "TRACE"; do I > need to set any that aren't set? I see that "Kernel hacking ---> Tracers" is enabled. You should have one tracer enabled for that trace_printk() to work. You have context switch tracer so it should be enough. You might need CONFIG_DEBUG_FS (but it is set in your 5.1 config) or it is just not mounted. So I have here: | debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) | tracefs on /sys/kernel/debug/tracing type tracefs (rw,nosuid,nodev,noexec,relatime) Does it work for you if you mount it? > Steve Berman Sebastian
