Re: [PATCH 2/2] tracing: Add CONFIG_TRACE_PRINTK_DEBUGGING to clean up kernel.h

Steven Rostedt <[email protected]> Sun, 21 Jun 2026 09:03:53 -0400
Newsgroups org.kernel.vger.linux-kbuild,org.freedesktop.lists.dri-devel,org.freedesktop.lists.intel-gfx,org.infradead.lists.linux-arm-kernel,org.kernel.vger.kvm,org.kernel.vger.linux-doc,org.kernel.vger.linux-ext4,org.kernel.vger.linux-kernel,org.kernel.vger.linux-nfs,org.kernel.vger.linux-rdma,org.kernel.vger.linux-trace-kernel,org.kernel.vger.linux-usb,org.ozlabs.lists.linuxppc-dev
Message-ID <20260621090353.24772584@fedora>
On Sun, 21 Jun 2026 13:55:31 +0100
David Laight <[email protected]> wrote:

> Indeed...
> Isn't trace_printk() just an extern?
> Having it defined somewhere isn't going to make any difference to build times.

No it is not. It is a macro to cut as many nanoseconds as possible as
trace_printk() was created to debug tight race conditions and any added
latency can make the race go away.

-- Steve