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Wysocki" , Danilo Krummrich , linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-modules@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v4 7/7] kernel.h: drop trace_printk.h In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <20251225170930.1151781-1-yury.norov@gmail.com> <20251225170930.1151781-8-yury.norov@gmail.com> <20251226115848.298465d4@gandalf.local.home> <20251228133150.1d5731d04bc1b685b0fe81c1@linux-foundation.org> <20251229111748.3ba66311@gandalf.local.home> <20260103005059.GA11015@joelbox2> Date: Mon, 05 Jan 2026 11:29:51 +0200 Message-ID: <254c1096c3b892923dd12b07a8b80291b88c0e9b@intel.com> Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Sat, 03 Jan 2026, Yury Norov wrote: > On Sat, Jan 03, 2026 at 02:57:58PM +0200, Andy Shevchenko wrote: >> On Fri, Jan 02, 2026 at 07:50:59PM -0500, Joel Fernandes wrote: >> > On Mon, Dec 29, 2025 at 11:17:48AM -0500, Steven Rostedt wrote: >> >> ... >> >> > I use trace_printk() all the time for kernel, particularly RCU development. >> > One of the key usecases I have is dumping traces on panic (with panic on warn >> > and stop tracing on warn enabled). This is extremely useful since I can add >> > custom tracing and dump traces when rare conditions occur. I fixed several >> > bugs with this technique. >> > >> > I also recommend keeping it convenient to use. >> >> Okay, you know C, please share your opinion what header is the best to hold the >> trace_printk.h to be included. > > What if we include it on Makefile level, similarly to how W=1 works? > > make D=1 // trace_printk() is available > make D=0 // trace_printk() is not available > make // trace_printk() is not available > > Where D stands for debugging. > > D=1 may be a default setting if you prefer, but the most important is > that every compilation unit will have an access to debugging without > polluting core headers. You do realize this means recompiling everything when adding D=1 for debugging? BR, Jani. -- Jani Nikula, Intel