From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) (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 EE24A301460; Sat, 25 Oct 2025 14:59:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761404400; cv=none; b=b9BiEFGDmxKzcqeWpjr8DEf+Zy5VxGDlsmjF0RoP6h5CklzcOfrcJvvrtf0+lQSXyoiPA18BsoKUKayIYWGJ5YWsyaMtKXq/NHsvr2Q/XEUCl1VNUqbBcTOx/ZYHpnIQVjLcCRqDkdzATjksFkbUjGPV9LCb07YM9NWa5gNzw2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761404400; c=relaxed/simple; bh=1JO+EN464i94sSls5+ZcLrofTbrCCyyLTqwSUlS3HrQ=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Xh65xheGk8rUV+9Mfk8zVSo/ukC6q8BCGLegxIKJ2LlwajIC8HlomQaI9mme8WDHESLCsq3ZvAfCbSGwFepMlClGiYx9JC7cC6u5E6XqnYt7LWxA751Txf7XOZdEI0+KGOZStNqAoHl0D6Fll1YIeTw+S2V2ISNNAkOuT68OdkE= 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=216.40.44.15 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 omf19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 2A92C56348; Sat, 25 Oct 2025 14:59:49 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf19.hostedemail.com (Postfix) with ESMTPA id 6111E20026; Sat, 25 Oct 2025 14:59:44 +0000 (UTC) Date: Sat, 25 Oct 2025 10:59:44 -0400 From: Steven Rostedt To: Alex Markuze Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Liam.Howlett@oracle.com, akpm@linux-foundation.org, bsegall@google.com, david@redhat.com, dietmar.eggemann@arm.com, idryomov@gmail.com, mingo@redhat.com, juri.lelli@redhat.com, kees@kernel.org, lorenzo.stoakes@oracle.com, mgorman@suse.de, mhocko@suse.com, rppt@kernel.org, peterz@infradead.org, surenb@google.com, vschneid@redhat.com, vincent.guittot@linaro.org, vbabka@suse.cz, xiubli@redhat.com, Slava.Dubeyko@ibm.com Subject: Re: [RFC PATCH 0/5] BLOG: per-task logging contexts with Ceph consumer Message-ID: <20251025105944.1a04e518@batman.local.home> In-Reply-To: References: <20251024084259.2359693-1-amarkuze@redhat.com> <20251024135301.0ed4b57d@gandalf.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-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: pc3a3bfpb9hcnm9iaxnw6do4upq79gnw X-Rspamd-Server: rspamout07 X-Rspamd-Queue-Id: 6111E20026 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18nBZUO/jhduNiWRSKvYzbdBO98QxDlMpA= X-HE-Tag: 1761404384-373123 X-HE-Meta: U2FsdGVkX1+4lKsGaA7TKsVLzBxuvMoWhjOFNULKRM5Mg0jsoYWD1a6mSIKQSnfaBR1DcTcfFpjvTbAMWYdymXTSdrSlXJdDkC3RM+lJ9uDjCpgSdxpk2ZxqRN11r1TPLtIVgMvSOdISCn0CFXKrE8tZ9SSWJagKo/U0ktmYl1lsN4n/M1if5zi06ycFz7Avb5aPvoUU9WaNalGOu6WGpUMPlpULHnk5g1BcY7RNnuNHnrTdZJSHT8TnDmxXQ13NCZAMIjzV0EXdr2FEBN9TBuvgBR8R77k6XtR/24SGMAy/GckjuLyBujCgzeWdfxKzmrP4UdmfShDq+dNV5a4mDdcPqo29q1dr On Sat, 25 Oct 2025 13:50:39 +0300 Alex Markuze wrote: > First of all, Ftrace is for debugging and development; you won't see > components or kernel modules run in production with ftrace enabled. > The main motivation is to have verbose logging that is usable for > production systems. That is totally untrue. Several production environments use ftrace. We have it enabled and used in Chromebooks and in Android. Google servers also have it enabled. > The second improvement is that the logs have a struct task hook which > facilitates better logging association between the kernel log and the > user process. > It's especially handy when debugging FS systems. So this is for use with debugging too? > > Specifically we had several bugs reported from the field that we could > not make progress on without additional logs. This still doesn't answer my question about not using ftrace. Heck, when I worked for Red Hat, we used ftrace to debug production environments. Did that change? -- Steve