LinuxPPC-Dev Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Steven Rostedt <rostedt@kernel.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	John Ogness <john.ogness@linutronix.de>,
	Thomas Gleixner <tglx@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Julia Lawall <julia.lawall@inria.fr>,
	Yury Norov <yury.norov@gmail.com>,
	linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org, dri-devel@lists.freedesktop.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org, linux-rdma@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-ext4@vger.kernel.org,
	linux-nfs@vger.kernel.org, kvm@vger.kernel.org,
	intel-gfx@lists.freedesktop.org
Subject: [PATCH 0/2] tracing: Move trace_printk.h out of kernel.h
Date: Sun, 21 Jun 2026 05:34:30 -0400	[thread overview]
Message-ID: <20260621093430.264983361@kernel.org> (raw)

There's been complaints about trace_printk() being defined in kernel.h as it
can increase the compilation time. As it is only used by some developers for
debugging purposes, it should not be in kernel.h causing lots of wasted CPU
cycles for those that do not ever care about it.

Instead, add a CONFIG_TRACE_PRINTK_DEBUGGING option that developers that do
use it can set and not have to always remember to add #include <linux/trace_printk.h>
to the files they add trace_printk() while debugging. It also means that
those that do not have that config set will not have to worry about wasted
CPU cycles as it is only include in the CFLAGS when the option is set, and
its completely ignored otherwise.

Steven Rostedt (2):
      tracing: Move non-trace_printk prototypes back to kernel.h
      tracing: Add CONFIG_TRACE_PRINTK_DEBUGGING to clean up kernel.h

----
 .../driver_development_debugging_guide.rst         |  2 +-
 Makefile                                           |  5 +++++
 arch/powerpc/kvm/book3s_xics.c                     |  1 +
 drivers/gpu/drm/i915/gt/intel_gtt.h                |  1 +
 drivers/gpu/drm/i915/i915_gem.h                    |  1 +
 drivers/hwtracing/stm/dummy_stm.c                  |  4 ++++
 drivers/infiniband/hw/hfi1/trace_dbg.h             |  1 +
 drivers/usb/early/xhci-dbc.c                       |  1 +
 fs/ext4/inline.c                                   |  1 +
 include/linux/kernel.h                             | 19 ++++++++++++++++++-
 include/linux/sunrpc/debug.h                       |  1 +
 include/linux/trace_printk.h                       | 22 +++-------------------
 kernel/trace/Kconfig                               | 10 ++++++++++
 kernel/trace/ring_buffer_benchmark.c               |  1 +
 kernel/trace/trace.h                               |  1 +
 samples/fprobe/fprobe_example.c                    |  1 +
 samples/ftrace/ftrace-direct-modify.c              |  1 +
 samples/ftrace/ftrace-direct-multi-modify.c        |  1 +
 samples/ftrace/ftrace-direct-multi.c               |  2 +-
 samples/ftrace/ftrace-direct-too.c                 |  2 +-
 samples/ftrace/ftrace-direct.c                     |  2 +-
 21 files changed, 56 insertions(+), 24 deletions(-)


             reply	other threads:[~2026-06-21 11:20 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-21  9:34 Steven Rostedt [this message]
2026-06-21  9:34 ` [PATCH 1/2] tracing: Move non-trace_printk prototypes back to kernel.h Steven Rostedt
2026-06-21 13:08   ` Yury Norov
2026-06-21 13:24     ` Steven Rostedt
2026-06-21  9:34 ` [PATCH 2/2] tracing: Add CONFIG_TRACE_PRINTK_DEBUGGING to clean up kernel.h Steven Rostedt
2026-06-21  9:47   ` Steven Rostedt
2026-06-21 13:39     ` Yury Norov
2026-06-21 13:57       ` Yury Norov
2026-06-21 10:13   ` Thomas Gleixner
2026-06-21 10:38     ` Steven Rostedt
2026-06-21 12:55     ` David Laight

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260621093430.264983361@kernel.org \
    --to=rostedt@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=bigeasy@linutronix.de \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=john.ogness@linutronix.de \
    --cc=julia.lawall@inria.fr \
    --cc=kvm@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=linux-stm32@st-md-mailman.stormreply.com \
    --cc=linux-trace-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mark.rutland@arm.com \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mhiramat@kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=yury.norov@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox