Re: [PATCH 3/3 v11] printk: Add monotonic, boottime, and realtime timestamps

From: Prarit Bhargava
Date: Tue Sep 19 2017 - 07:52:42 EST

On 09/17/2017 06:46 AM, Sergey Senozhatsky wrote:

> I'm a bit uncomfortable with the "breaks user space" part. since this
> is a strictly debugging option, would it be sufficient to store those
> extended timestamps as prefixes of every message?
> see (sorry for "self-quoting"):

Sergey, I haven't forgotten about the above. It's something
I'm going to look at after this initial patchset is done.


> each message, thus, will be in the following format
> [current header: loglevel, timestamp, etc] [extended printk data] message text
> extended printk data can contain your monotonic/etc timestamps, and
> anything else.
> and then it's up to you how do you grep the messages and process the
> extended data. but the point is - user space tools (journald, dmesg,
> etc.) stays intact. which is kinda nice.
> so we can avoid that chicken and egg problem: we break user space
> by merging the patchset but user space people don't want to talk
> about any fixes until we break those tools.
> -ss