Re: [PATCH v14 2/5] ring-buffer: Skip invalid sub-buffers when validating persistent ring buffer

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Mon, 30 Mar 2026 16:28:22 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Mon, 30 Mar 2026 16:22:10 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
> > On Mon, 30 Mar 2026 21:50:04 +0900
> > "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> > 
> > > @@ -2042,7 +2065,8 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer)
> > >  	local_set(&cpu_buffer->entries, entries);
> > >  	local_set(&cpu_buffer->entries_bytes, entry_bytes);
> > >  
> > > -	pr_info("Ring buffer meta [%d] is from previous boot!\n", cpu_buffer->cpu);
> > > +	pr_info("Ring buffer meta [%d] is from previous boot! (%d pages discarded)\n",
> > > +		cpu_buffer->cpu, discarded);  
> > 
> > As pages should never be discarded unless something went wrong, let's only
> > print that if there were discarded pages.
> > 
> > 	if (discarded) {
> > 		pr_info("Ring buffer meta [%d] is from previous boot! (%d pages discarded)\n",
> > 			cpu_buffer->cpu, discarded);
> > 	} else {
> > 		pr_info("Ring buffer meta [%d] is from previous boot!\n", cpu_buffer->cpu);
> > 	}
> 
> Or perhaps:
> 
> 	pr_info("Ring buffer meta [%d] is from previous boot!", cpu_buffer->cpu);
> 	if (discarded)
> 		pr_cont(" (%d pages discarded)", discarded);
> 	pr_cont("\n");

OK. I'll do this.

Thanks for the comment!

> 
> -- Steve
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>