Re: [PATCH] ftrace: add ftrace_graph_max_depth kernel parameter

[Steven Rostedt]

On Thu, 02 Mar 2017 17:35:31 -0800
Todd Brandt <todd.e.brandt@xxxxxxxxxxxxxxx> wrote:

> > I could toy with the idea, implement it, and see what breaks.  
> If it was possible that would be great. The reason I ask is because I've
> implemented a tool called analyze_boot which I intend to upgrade to use
> early callgraph trace (it just uses initcall_debug now):
> 
> https://marc.info/?l=linux-pm&m=148667508500967&w=2
> 
> I'll have it do the same thing for boot that analyze_suspend does for
> suspend/resume: display the callgraphs for each initcall instance in
> html. The max_graph_depth param is necessary to keep the html outputs
> manageable. Most laptop/desktop machines running standard linux seem to
> take at least 5 seconds for boot, but we've got some servers optimized
> to boot in less than a second (which means I'd only be able to trace
> half of the boot timeline or less). The more coverage I can get the
> better.
> 
> P.S. I submitted the analyze_boot tool on the pm list but Raphael didn't
> think it would fit in the PM tree. Would you be willing to accept this
> script? (I can resubmit but nothing's changed since the RESEND).

That may be something to ask Andrew about. He's sorta the one to dump
changes to that don't seem to fit anywhere else.

-- Steve