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a=rsa-sha256; c=relaxed/relaxed; d=landley.net; s=dreamhost; t=1736293215; bh=MzZVLt/froHNJpqS/hnTr0WcD2TA71IY/I10TjTbdLM=; h=Date:Subject:To:Cc:From:Content-Type:Content-Transfer-Encoding; b=jO7QwvW1L8oZSqv0r9LB0yzBQV68joLMa5DO67oItlIopYi6cGwVRvRaOqquycLtY SfOGpHxvpCqBU8Xehbj0KdYtFy6VXAVjlzhb6xSh5g8nG/OdGdVD9tby9ufmmUj46V UT4IoGgkWrVyTHuod3NF95GQMvzuRg+J1/5lMCp0JQf0B7CMxbbb0MXGWaxoCGKMRT kFI+jzKnts8l3cAEGWfPjN02jhJzNoo3t2nVS7wzABdt8E+duLgWe0ZwvU31MY75oU AAnoHfSZANki0Ar+YBTScUPduPymGARvCCBvjTb6uu9+ktUueFPpbp0j/WXmmYJEoS USEm+HyRaar0g== Message-ID: <211b015d-44e5-4e64-9e44-5968d86dfac4@landley.net> Date: Tue, 7 Jan 2025 17:40:13 -0600 Precedence: bulk X-Mailing-List: linux-embedded@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: boot markers ideas (was RE: [boot-time] jent_mod_init on beagleplay) To: "Bird, Tim" , Francesco Valla , Stephan Mueller , Shankari Cc: Linux Embedded References: <1964175.7Z3S40VBb9@fedora.fritz.box> <4095066.UUX0tPYDPe@tauon.atsec.com> <22372644.4csPzL39Zc@fedora.fritz.box> Content-Language: en-US From: Rob Landley In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/7/25 15:42, Bird, Tim wrote: > > >> -----Original Message----- >> From: Francesco Valla > ... >>> I wanted to provide an update on my recent contributions to the BeaglePlay >>> project. I have recently started contributing and have been analyzing the >>> boot time of the init process. Below is the output from the system log: >>> >>> debian@BeaglePlay:~$ dmesg | grep "init process" >>> [ 1.480490] Run /init as init process >>> > ... > >> >> I started the same journey around a week ago, and it's proving a valuable >> experience. >> >> After some trimming, I reached a (reported) init startup time of around 0.6s: >> >> root@beagleplay-ti:~# dmesg|grep /sbin >> [ 0.630046] Run /sbin/init as init process > > > I'm starting to think that we should be using this particular kernel message > as a consistent "boot marker" for kernel startup time. It's certainly not the > end of when the kernel is doing stuff on startup, but I do believe it marks > one of the important transition points (start of user space activity), and > it seems to be ubiquitously reported. > > At Plumbers, I had proposed to introduce a set of specific instrumentation > points in the kernel and use those as key checkpoints. But IMHO it's good > to use existing printk messages where possible, since they're already present - no > additional instrumentation needed. Is there a place to get this measuring script other than fishing it out of a webmail archive? https://www.spinics.net/lists/linux-embedded/msg04363.html The most recent wiki mention in the archive subject lines was https://www.spinics.net/lists/linux-embedded/msg04336.html and trying to find this effort in elinux.org's top right search bar found https://elinux.org/Boot-up_Time_Reduction_Howto which "view history" says was last touched in 2010... Rob P.S. Meanwhile, python 3 goes in quite the opposite direction: https://landley.net/notes-2024.html#09-04-2024