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Sergey Senozhatsky
9627808d2d
Since commit5c2992ee7f("printk: remove console flushing special cases for partial buffered lines") we don't print cont fragments to the consoles; cont lines are now proper log_buf entries and there is no "consecutive continuation flag" anymore: we either have 'c' entries that mark continuation lines without fragments; or '-' entries that mark normal logbuf entries. There are no '+' entries anymore. However, we still have a small leftover - presence of ext_console drivers disables kernel cont support and we flush each pr_cont() and store it as a separate log_buf entry. Previously, it worked because msg_print_ext_header() had that "an optional external merge of the records" functionality: if (msg->flags & LOG_CONT) cont = (prev_flags & LOG_CONT) ? '+' : 'c'; We don't do this as of now, so keep kernel cont always enabled. Note from pmladek: The original purpose was to get full information including the metadata and dictionary via extended console drivers, see commit6fe29354be("printk: implement support for extended console drivers"). The dictionary probably was the most important part but it was actually lost: static void cont_flush(void) { [...] log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec, NULL, 0, cont.buf, cont.len); Nobody noticed because the only dictionary user is dev_printk() and dev_cont() is _not_ defined. Link: http://lkml.kernel.org/r/[email protected] To: Steven Rostedt <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Dmitriy Vyukov <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: LKML <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Signed-off-by: Sergey Senozhatsky <[email protected]> [[email protected]: Updated commit message] Signed-off-by: Petr Mladek <[email protected]>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.