Re: Boot-time dumping of ftrace fuctiongraph buffer

2024-02-02 Thread Ahmad Fatoum
Hello Steve, On 02.02.24 02:46, Steven Rostedt wrote: > On Thu, 1 Feb 2024 13:21:37 +0100 > Ahmad Fatoum wrote: >> For this to be maximally useful, I need to configure this not only at >> boot-time, >> but also dump the ftrace buffer at boot time. Probe deferral can hinder the >> kernel from >>

Re: Boot-time dumping of ftrace fuctiongraph buffer

2024-02-02 Thread Ahmad Fatoum
Hello Masami-san, On 02.02.24 07:04, Masami Hiramatsu (Google) wrote: > On Thu, 1 Feb 2024 13:21:37 +0100 > Ahmad Fatoum wrote: >> For drivers that don't call dev_err_probe, I find myself sometimes doing >> printf >> debugging inside the probe function. [snip] >> I would like to replace this w

Re: Boot-time dumping of ftrace fuctiongraph buffer

2024-02-01 Thread Google
Hi Ahmad, On Thu, 1 Feb 2024 13:21:37 +0100 Ahmad Fatoum wrote: > Hello, > > I semi-regularly debug probe failures. For drivers that use dev_err_probe > rigorously, this is a quick matter: The probe function records a deferral > reason > and if the deferral persists, deferred_probe_timeout_wor

Re: Boot-time dumping of ftrace fuctiongraph buffer

2024-02-01 Thread Steven Rostedt
On Thu, 1 Feb 2024 13:21:37 +0100 Ahmad Fatoum wrote: > Hello, > > I semi-regularly debug probe failures. For drivers that use dev_err_probe > rigorously, this is a quick matter: The probe function records a deferral > reason > and if the deferral persists, deferred_probe_timeout_work_func() wi

Boot-time dumping of ftrace fuctiongraph buffer

2024-02-01 Thread Ahmad Fatoum
Hello, I semi-regularly debug probe failures. For drivers that use dev_err_probe rigorously, this is a quick matter: The probe function records a deferral reason and if the deferral persists, deferred_probe_timeout_work_func() will print the collected reasons, even if PID 1 is never started. For