From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB623C433EF for ; Wed, 9 Mar 2022 08:01:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229632AbiCIICf (ORCPT ); Wed, 9 Mar 2022 03:02:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229774AbiCIIC1 (ORCPT ); Wed, 9 Mar 2022 03:02:27 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AF16169200 for ; Wed, 9 Mar 2022 00:01:28 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0B87A60F26 for ; Wed, 9 Mar 2022 08:01:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C027C340EE; Wed, 9 Mar 2022 08:01:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646812887; bh=v3kCSOlPYnjQWLgSvNmxaNEN5wv4j9rO5qcLBkRkMHo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cDTY3XffBbD3A8QDjhNkD5yGc9ypqwpzzem4gW/Zd+oxcSuK8A5w/OrorKIxvhTLS JvsZslWk7G6hy+OI/3rC9P7I+ln0NweMjX2ClnC+sDiMnkqjoT5dUVlcrr4MEXT5+d COJ861hGPcAqeMT6xcirRBlbGwSYspIQrRBm/0L0QzISG4dEFE5gv5yZ7o2zx+QehK I9O6JDgw7f+sFTTdQmwppzb0zJxrE5slb25ewrK+PNgVbFEhn7xz04lun+WI+pVAE2 uqtH70VBH/YqgZNr5tK/p+5lIORy1FlZRguXWPdekBuMrSHA8JMbZa5phEm6Rb7AqC usSm+biJJvGTw== Date: Wed, 9 Mar 2022 17:01:24 +0900 From: Masami Hiramatsu To: Padmanabha Srinivasaiah Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org Subject: Re: tracing : bootconfig : Early boot config for non intrd systems Message-Id: <20220309170124.82dcfadbcda6f8ab6ed51797@kernel.org> In-Reply-To: <20220308174829.GA2471@pswork> References: <20220307184011.GA2570@pswork> <20220308163600.3109f19854c7b051924f262b@kernel.org> <20220308174829.GA2471@pswork> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 8 Mar 2022 18:48:29 +0100 Padmanabha Srinivasaiah wrote: > Hello Masami Hiramatsu, > > On Tue, Mar 08, 2022 at 04:36:00PM +0900, Masami Hiramatsu wrote: > > Hello Padmanabha, > > > > On Mon, 7 Mar 2022 19:40:11 +0100 > > Padmanabha Srinivasaiah wrote: > > > > > Hello Masami Hiramatsu, > > > > > > Thanks for detailed explanation on boot time tracing using early boot configuration file. > > > https://linuxfoundation.org/wp-content/uploads/boottrace-LF-live-2021-update.pdf > > > > > > Also for https://lwn.net/Articles/806002/. > > > > > > Latter link also states we can embed boot config into the kernel image for non intrd based system. > > > > Ah, that was an original plan, but since no one interested in, I didn't implement it. > > So we still need the initrd for bootconfig. > > > Ok. > > > > > > I tried searching mailing lists not able to find pointer for same. > > > > > > A hint/pointer on how-to will be very helpful. > > > > BTW, what is your problem, could you share your use-case? > > > > I have hetrogenous system which donot use intrd. > > The use-case is to capture __system wide__ event based tracing for > boot-up sequence, which also covers early stage of default init programs > used. > > As buffer size is limited, will have hand-picked events set configured. Hm, so I guess you will boot linux from your custom bootloader (or binary loader on sub processor?). Can you even try to add a dummy initrd? or are you OK to rebuild kernel for embedding the bootconfig data? If both don't work, the solution will be architecture or bootloader specific. Thank you, -- Masami Hiramatsu