From nobody Wed Oct 8 00:39:04 2025 Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) (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 2B5451FFC46; Thu, 3 Jul 2025 15:52:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751557949; cv=none; b=B8EYlNQE/DHucTOjk1GYtUdn45zp2mt7exSKXsD/ZTmLNgxOcU1O8um5Nx+nExNrKXXri0i4hDYiXfGwjBjC4OSqOLUy1osD9JNHlT7O49Jf11EVxjWWTRDEApsbSyGUgPwtqCWyoNG7IQ4ztJAP45jEMwcVpsqcdUWnw8CdN5s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751557949; c=relaxed/simple; bh=jwgKZTPaZQlwll7qCULdeQgNvtUTTT/x/yMZSiwNCwE=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=on3Gz+GBjRpxeI8fCUX1PX1KpZaPhk0x7fQ9JGLLePUtPkE3CRQQt1JHIC4DSPjogv3KpkEDC2j2xzo54U/MnSAf7cun4VSMc8s9As0SmQzgiz598P2Tv1DtdkFcWibnaAUUb+HO+sgzxyaWCMNT2paLChDx6Ze/kwiQv+c6Zqw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 6BE4C1D3D6D; Thu, 3 Jul 2025 15:52:25 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf14.hostedemail.com (Postfix) with ESMTPA id 5B44433; Thu, 3 Jul 2025 15:52:23 +0000 (UTC) Date: Thu, 3 Jul 2025 11:52:22 -0400 From: Steven Rostedt To: LKML , Linux trace kernel Cc: Masami Hiramatsu , Mathieu Desnoyers , Mark Rutland , Linus Torvalds , Alexandre Ghiti , ChenMiao , linux-arch@vger.kernel.org Subject: [RFC][PATCH] ftrace: Make DYNAMIC_FTRACE always enabled for architectures that support it Message-ID: <20250703115222.2d7c8cd5@batman.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: dfnkcxf73rcxdf54d4ej8zbyr86zosuy X-Rspamd-Server: rspamout04 X-Rspamd-Queue-Id: 5B44433 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1941fakycO7fuixZ+xnYJobriHijGZxFo0= X-HE-Tag: 1751557943-567718 X-HE-Meta: U2FsdGVkX1+SUmEj7Iin14aLs/X5m3iQXwVMmZcDYZr7pBi5yC56SE0+vRaEXCEvgookkK+fOlzaZS2AS55vrq/oXrmgjhD/y6YMUUGbIluIRTKQFs+0zKEH/1KkAVpWs9QXzLzOf8P47ivGbBq0cxh5h/O5unyC4+BizN24I1qIaT11atH6g149UACqZaTkZVW75PrcHbnm7hWhW7f3/ZmY3cxc/aHjoqYELWJ0AJlecP7azdaNrdHQANkRvrDyuRKBQ6g7ESMnDGXtfkB34DRbaAHZMtYQlqTuI/+hIwbJ2ehP3dWSyrstyaVNojv5teDKzJIz3kKaP9HOXD5czraiKZy8QjIO3xeY0mjY+VtbmUuiJSKxN6oeZGxRx9Cr2CRmHCT1KoinVz7GXLYRFA== Content-Type: text/plain; charset="utf-8" From: Steven Rostedt ftrace has two flavors: 1) static: Where every function always calls the ftrace trampoline 2) dynamic: Where each function has nops that can be changed on demand to jump to the ftrace trampoline when needed. The static flavor has very high performance overhead and was only created to make it easier for architectures to implement the dynamic flavor. An architecture developer can first implement the static ftrace to make sure the trampolines work before working on the more complicated dynamic aspect of ftrace. Once the architecture can support dynamic ftrace, there's no reason to continue to support the static flavor. In fact, the static flavor tends to bitrot and bugs start to appear in them. Remove the prompt to pick DYNAMIC_FTRACE and simply enable it if the architecture supports it. Link: https://lore.kernel.org/all/f7e12c6d-892e-4ca3-9ef0-fbb524d04a48@ghit= i.fr/ Signed-off-by: Steven Rostedt (Google) --- kernel/trace/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a3f35c7d83b6..28afc6941e7a 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -275,7 +275,7 @@ config FUNCTION_TRACE_ARGS funcgraph-args (for the function graph tracer) =20 config DYNAMIC_FTRACE - bool "enable/disable function tracing dynamically" + bool depends on FUNCTION_TRACER depends on HAVE_DYNAMIC_FTRACE default y --=20 2.47.2