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Date: Thu, 13 Jun 2024 09:32:33 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Andy Chiu <andy.chiu@sifive.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt
 <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Alexandre Ghiti
 <alexghiti@rivosinc.com>, Zong Li <zong.li@sifive.com>, Masami Hiramatsu
 <mhiramat@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Nathan
 Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>,
 Bill Wendling <morbo@google.com>, Justin Stitt <justinstitt@google.com>,
 Puranjay Mohan <puranjay@kernel.org>, Palmer Dabbelt <palmer@rivosinc.com>,
 linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
 linux-trace-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH 2/8] tracing: do not trace kernel_text_address()
Message-ID: <20240613093233.0b349ed0@rorschach.local.home>
In-Reply-To: <20240613-dev-andyc-dyn-ftrace-v4-v1-2-1a538e12c01e@sifive.com>
References: <20240613-dev-andyc-dyn-ftrace-v4-v1-0-1a538e12c01e@sifive.com>
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On Thu, 13 Jun 2024 15:11:07 +0800
Andy Chiu <andy.chiu@sifive.com> wrote:

> kernel_text_address() and __kernel_text_address() are called in
> arch_stack_walk() of riscv. This results in excess amount of un-related
> traces when the kernel is compiled with CONFIG_TRACE_IRQFLAGS. The
> situation worsens when function_graph is active, as it calls
> local_irq_save/restore in each function's entry/exit. This patch adds
> both functions to notrace, so they won't show up on the trace records.

I rather not add notrace just because something is noisy.

You can always just add:

 echo '*kernel_text_address' > /sys/kernel/tracing/set_ftrace_notrace

and achieve the same result.

-- Steve