From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EEC840D596; Mon, 22 Jun 2026 08:54:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782118454; cv=none; b=tV2P8WECAXZbyl/5HlOSVgPbqttOdeL8CKbw7P17BpFxwPSinyd/f9DHckxKkaco2V+VNOkjGE3cDIpqsiShiJBL/cM+HFFx4HtKT35dgraYPB+PhXd3hiqLZYKaQ7GILVl5icPH3ZNeurEu4S4hzGAKbi9UJaXvTv4UFKurY9w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782118454; c=relaxed/simple; bh=OAWmV8skIxMVw/WDm7TlekxPmF8xJMXvHUg1xzxkcD0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OjWViWBEWY75Dib0nocssY8HZ0CJB8m/hrsROFYW8Sf4dP2guecWBadIQJa4MR4ds/C9Wm6Bfd0hQt6KzYgd8HBkH4gBBq2LjXfzoTK1Pv91XV1Rwag8YNs39JK1gcr1XWfRpggsnAUdhRpQuyV+IIlY/F1DjFjzL3Qsypw8mVk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=TuPlTRCU; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TuPlTRCU" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=y2+mOP/j6lYd9qVyAamBJsy1djQW4CKGJJUDwRnuyXs=; b=TuPlTRCUatJuuJgUUAwvzHwMKv dWwVfsTqUjTJh9SX5fPBCQGdiQcrZu7Ws4gSZKgN7rA0kNKxui7b5LEtKWEEQDe4V7j5A8N0jYuRY uas/iKoJjFjR3gKpo0uOWWxjsbSNbU4N4b8MGJpMvU190ZELYDlzfAoftHa96t+aSCVqbpoMUbpfL uOWtb+WeGCTtTYOdcuf3kQ/LcfWhZsQK+C/ri3C/zOHCtiyE1n8uDvDi3TDA+Xy225DqvitJuIeN0 RneapmfngTU0PhOUCG9gkRpGwiGc3BAbq6jkG1ZvAJCnP1chuakPaLn4PyoFg+CyhHRv/kOJ0Ywl3 cXoCNRYg==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wba77-00000003u7U-1iUV; Mon, 22 Jun 2026 08:34:42 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 52395300B5F; Mon, 22 Jun 2026 10:34:40 +0200 (CEST) Date: Mon, 22 Jun 2026 10:34:40 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Linus Torvalds , Sebastian Andrzej Siewior , John Ogness , Thomas Gleixner , Julia Lawall , Yury Norov , 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: Re: [PATCH 0/2] tracing: Move trace_printk.h out of kernel.h Message-ID: <20260622083440.GX49951@noisy.programming.kicks-ass.net> References: <20260621093430.264983361@kernel.org> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260621093430.264983361@kernel.org> On Sun, Jun 21, 2026 at 05:34:30AM -0400, Steven Rostedt wrote: > 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 > 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. Did you forget your C 101 class? If you use a function, you gotta include the relevant header. You don't see userspace saying: 'Hey, you know what, perhaps we should add stdio.h to every other header, just in case someone wants to printf()' either. I really don't understand your argument. Yes, maybe someone will forget and then either their editor (if they have a halfway modern setup with LSP enabled) or their build will complain, but so what? This is all trivial stuff, surely we have more pressing matters to concern outselves with?