Re: [PATCH 1/2] printk: remove unused flag LOG_NOCONS

From: Petr Mladek
Date: Tue Jun 05 2018 - 08:56:16 EST


On Mon 2018-06-04 17:33:42, Steven Rostedt wrote:
> On Thu, 31 May 2018 14:16:33 +0200
> Petr Mladek <pmladek@xxxxxxxx> wrote:
>
> > > enum log_flags {
> > > - LOG_NOCONS = 1, /* already flushed, do not print to console */
> > > - LOG_NEWLINE = 2, /* text ended with a newline */
> > > - LOG_PREFIX = 4, /* text started with a prefix */
> > > - LOG_CONT = 8, /* text is a fragment of a continuation line */
> > > + LOG_NEWLINE = 1, /* text ended with a newline */
> > > + LOG_PREFIX = 2, /* text started with a prefix */
> > > + LOG_CONT = 4, /* text is a fragment of a continuation line */
> > > };
> >
> > Please, do not renumber the bits if there is no real need for it.
> > The format of the log buffer is read also by external tool like
> > "crash". It seems that "crash" ignores these flags but...
>
> Then what's the problem for renumbering? I've renumbered internal flags
> before. No one complained about it.

Steven, did you renumber enum log_flags or flags in a different
subsystem?

Note that struct printk_log is a bit special because it is used by
the "crash" tool to implement the dmesg/log command. While "crash"
tool does not have special handling for most other internal
structures.

I have double checked "crash" sources and it ignores these flags
at the moment but it might change in the future => I suggest to
do not renumber them if there is not a real need.

Best Regards,
Petr