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| author | James Byrne <james.byrne@origamienergy.com> | 2019-09-02 11:18:16 +0000 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2019-09-06 16:26:36 +0200 |
| commit | 085a3a8fdf3e2fbd4678dbeccbb656bd328b3715 (patch) | |
| tree | 7ec1a0395e66fe9478f7fa0b9bb1cfd91f1d4432 /Documentation/ABI | |
| parent | 35c35493b0e3343522256f6054516f4e2161a6d4 (diff) | |
| download | linux-085a3a8fdf3e2fbd4678dbeccbb656bd328b3715.tar.gz linux-085a3a8fdf3e2fbd4678dbeccbb656bd328b3715.tar.bz2 linux-085a3a8fdf3e2fbd4678dbeccbb656bd328b3715.zip | |
ABI: Update dev-kmsg documentation to match current kernel behaviour
Commit 5aa068ea4082 ("printk: remove games with previous record flags")
abolished the practice of setting the log flag to 'c' for the first
continuation line and '+' for subsequent lines. Now all continuation
lines are flagged with 'c' and '+' is never used.
Update the 'dev-kmsg' documentation to remove the reference to the
obsolete '+' flag. In addition, state explicitly that only 8 bits of the
<N> syslog prefix are used for the facility number when writing to
/dev/kmsg.
Link: http://lkml.kernel.org/r/0102016cf1b26630-8e9b337b-da49-43c6-b028-4250c2fac3ef-000000@eu-west-1.amazonses.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/dev-kmsg | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg index fff817efa508..f307506eb54c 100644 --- a/Documentation/ABI/testing/dev-kmsg +++ b/Documentation/ABI/testing/dev-kmsg @@ -12,7 +12,7 @@ Description: The /dev/kmsg character device node provides userspace access The logged line can be prefixed with a <N> syslog prefix, which carries the syslog priority and facility. The single decimal prefix number is composed of the 3 lowest bits being the syslog - priority and the higher bits the syslog facility number. + priority and the next 8 bits the syslog facility number. If no prefix is given, the priority number is the default kernel log priority and the facility number is set to LOG_USER (1). It @@ -90,13 +90,12 @@ Description: The /dev/kmsg character device node provides userspace access +sound:card0 - subsystem:devname The flags field carries '-' by default. A 'c' indicates a - fragment of a line. All following fragments are flagged with - '+'. Note, that these hints about continuation lines are not - necessarily correct, and the stream could be interleaved with - unrelated messages, but merging the lines in the output - usually produces better human readable results. A similar - logic is used internally when messages are printed to the - console, /proc/kmsg or the syslog() syscall. + fragment of a line. Note, that these hints about continuation + lines are not necessarily correct, and the stream could be + interleaved with unrelated messages, but merging the lines in + the output usually produces better human readable results. A + similar logic is used internally when messages are printed to + the console, /proc/kmsg or the syslog() syscall. By default, kernel tries to avoid fragments by concatenating when it can and fragments are rare; however, when extended |