lkml.org 
[lkml]   [2017]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: kernel CI: printk loglevels in kernel boot logs?
On (11/22/17 20:52), Fengguang Wu wrote:
[..]
> > well, I think that that "consoles_format=syslog" command line parameter
> > will be enabled only by those who actually want to have it - Fengguang's
> > build robot and kernelCI (+ may be more setups). so I'd probably assume
> > there are low risks here. may be I'm wrong.
>
> Yes, since it needs explicit enabling, local parsers should stay
> working. Unless we send dmesg to other developers, but then they
> might also receive $(dmesg --raw) outputs and need to handle <%u>
> prefixes, too.
>
> > I think it makes sense to have syslog's format "<%u>[timestamp] text\n"
> > on serial consoles (time stamp when PRINTK_TIME set; <%u> when
> > consoles_format=syslog set).
>
> Thanks. Since the 0day scripts can already parse that format (code
> is listed below), we should quickly benefit from that feature when
> it's mainlined.

okay... who's going to send the patch? kernelCI folks?

I have some sort of a patch. added console_msg_format= with the only
available option so far - "syslog". may be people would want to have
boot time, etc. on their consoles. who knows. may be msg_format will
be extended someday in the future or may be not, and we can do
something like "console_format_syslog" (or any better name).

Not-yet-signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++
kernel/printk/printk.c | 21 ++++++++++++++++++++-
2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 62436bd5f34a..42113e5181b2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -640,6 +640,17 @@
console=brl,ttyS0
For now, only VisioBraille is supported.

+ console_msg_format=
+ [KNL] Control message format
+ By default we print messages in "[time stamp] text\n"
+ format (time stamp may not be printed, depending on
+ CONFIG_PRINTK_TIME or `printk_time' param).
+ syslog
+ Switch to syslog format (similar to "dmesg --raw" or
+ reading from /proc/kmsg): "<%u>[time stamp] text\n"
+ IOW, each message is getting prepended with the
+ facility and loglevel prefix.
+
consoleblank= [KNL] The console blank (screen saver) timeout in
seconds. A value of 0 disables the blank timer.
Defaults to 0.
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5d81206a572d..034f3ad85f5b 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -277,6 +277,13 @@ EXPORT_SYMBOL(console_set_on_cmdline);
/* Flag: console code may call schedule() */
static int console_may_schedule;

+enum con_msg_format {
+ MSG_FORMAT_DEFAULT = 1,
+ MSG_FORMAT_SYSLOG = 2,
+};
+
+static int console_msg_format = MSG_FORMAT_DEFAULT;
+
/*
* The printk log buffer consists of a chain of concatenated variable
* length records. Every record starts with a record header, containing
@@ -1913,6 +1920,15 @@ static int __add_preferred_console(char *name, int idx, char *options,
c->index = idx;
return 0;
}
+
+static int __init console_msg_format_setup(char *str)
+{
+ if (!strncmp(str, "syslog", 6))
+ console_msg_format = MSG_FORMAT_SYSLOG;
+ return 1;
+}
+__setup("console_msg_format=", console_msg_format_setup);
+
/*
* Set up a console. Called via do_early_param() in init/main.c
* for each "console=" parameter in the boot command line.
@@ -2215,7 +2231,10 @@ void console_unlock(void)
goto skip;
}

- len += msg_print_text(msg, false, text + len, sizeof(text) - len);
+ len += msg_print_text(msg,
+ console_msg_format & MSG_FORMAT_SYSLOG,
+ text + len,
+ sizeof(text) - len);
if (nr_ext_console_drivers) {
ext_len = msg_print_ext_header(ext_text,
sizeof(ext_text),
--
2.15.0
\
 
 \ /
  Last update: 2017-11-23 04:00    [W:0.078 / U:0.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site