1. 08 May, 2012 7 commits
  2. 07 May, 2012 4 commits
    • Kay Sievers's avatar
      printk: convert byte-buffer to variable-length record buffer · 7ff9554b
      Kay Sievers authored
      - Record-based stream instead of the traditional byte stream
        buffer. All records carry a 64 bit timestamp, the syslog facility
        and priority in the record header.
      
      - Records consume almost the same amount, sometimes less memory than
        the traditional byte stream buffer (if printk_time is enabled). The record
        header is 16 bytes long, plus some padding bytes at the end if needed.
        The byte-stream buffer needed 3 chars for the syslog prefix, 15 char for
        the timestamp and a newline.
      
      - Buffer management is based on message sequence numbers. When records
        need to be discarded, the reading heads move on to the next full
        record. Unlike the byte-stream buffer, no old logged lines get
        truncated or partly overwritten by new ones. Sequence numbers also
        allow consumers of the log stream to get notified if any message in
        the stream they are about to read gets discarded during the time
        of reading.
      
      - Better buffered IO support for KERN_CONT continuation lines, when printk()
        is called multiple times for a single line. The use of KERN_CONT is now
        mandatory to use continuation; a few places in the kernel need trivial fixes
        here. The buffering could possibly be extended to per-cpu variables to allow
        better thread-safety for multiple printk() invocations for a single line.
      
      - Full-featured syslog facility value support. Different facilities
        can tag their messages. All userspace-injected messages enforce a
        facility value > 0 now, to be able to reliably distinguish them from
        the kernel-generated messages. Independent subsystems like a
        baseband processor running its own firmware, or a kernel-related
        userspace process can use their own unique facility values. Multiple
        independent log streams can co-exist that way in the same
        buffer. All share the same global sequence number counter to ensure
        proper ordering (and interleaving) and to allow the consumers of the
        log to reliably correlate the events from different facilities.
      Tested-by: default avatarWilliam Douglas <william.douglas@intel.com>
      Signed-off-by: default avatarKay Sievers <kay@vrfy.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7ff9554b
    • Paul Gortmaker's avatar
      powerpc: fix compile fail in hugetlb cmdline parsing · 89528127
      Paul Gortmaker authored
      Commit 9fb48c74
      
          "params: add 3rd arg to option handler callback signature"
      
      added an extra arg to the function, but didn't catch all the use
      cases needing it, causing this compile fail in mpc85xx_defconfig:
      
       arch/powerpc/mm/hugetlbpage.c:316:4: error: passing argument 7 of
       'parse_args' from incompatible pointer type [-Werror]
      
       include/linux/moduleparam.h:317:12: note: expected
      	 'int (*)(char *, char *, const char *)' but argument is of type
      	 'int (*)(char *, char *)'
      
      This function has no need to printk out the "doing" value, so
      just add the arg as an "unused".
      
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jim Cromie <jim.cromie@gmail.com>
      Cc: Jason Baron <jbaron@redhat.com>
      Cc: Becky Bruce <beckyb@kernel.crashing.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      89528127
    • Zhi Yong Wu's avatar
      9ff1f838
    • Greg Kroah-Hartman's avatar
      Revert "dynamic_debug: remove unneeded includes" · fef15d2f
      Greg Kroah-Hartman authored
      This reverts commit 04db6e5f.
      
      Odds are, we really don't want to revert all of these, and need to be
      more careful in the future to make sure we don't break the build of
      other arches.
      Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      Cc: Jim Cromie <jim.cromie@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fef15d2f
  3. 05 May, 2012 3 commits
  4. 04 May, 2012 7 commits
  5. 02 May, 2012 10 commits
  6. 01 May, 2012 1 commit
  7. 30 Apr, 2012 8 commits
    • Jim Cromie's avatar
      dynamic_debug: init with early_initcall, not arch_initcall · 3ec5652a
      Jim Cromie authored
      1- Call dynamic_debug_init() from early_initcall, not arch_initcall.
      2- Call dynamic_debug_init_debugfs() from fs_initcall, not module_init.
      
      RFC: This works for me on a 64 bit desktop and a i586 SBC, but is
      untested on other arches.  I presume there is or was a reason
      original code used arch_initcall, maybe the constraints have changed.
      
      This makes facility available as soon as possible.
      
      2nd change has a downside when dynamic_debug.verbose=1; all the
      vpr_info()s called in the proc-fs code are activated, causing
      voluminous output from dmesg.  TBD: Im unsure of this explanation, but
      the output is there.  This could be fixed by changing those callsites
      to v2pr_info(if verbose > 1).
      
      1st change is still not early enough to enable pr_debugs in
      kernel/params, so parsing of boot-args isnt logged.  The reparse of
      those args is however visible after params.dyndbg="+p" is processed.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3ec5652a
    • Jim Cromie's avatar
      dynamic_debug: update Documentation/*, Kconfig.debug · 29e36c9f
      Jim Cromie authored
      In dynamic-debug-howto.txt:
      
      - add section: Debug Messages at Module Initialization Time
      - update flags indicators in example outputs to include '='
      - make flags descriptions tabular
      - add item on '_' flag-char
      - add dyndbg, boot-args examples
      - rewrap some paragraphs with long lines
      
      In Kconfig.debug, note that compiling with -DDEBUG enables all
      pr_debug()s in that code.
      
      In kernel-parameters.txt, add dyndbg and module.dyndbg items,
      and deprecate ddebug_query.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      29e36c9f
    • Jim Cromie's avatar
      dynamic_debug: add modname arg to exec_query callchain · 8e59b5cf
      Jim Cromie authored
      Pass module name into ddebug_exec_queries(), ddebug_exec_query(), and
      ddebug_parse_query() as separate parameter.  In ddebug_parse_query(),
      the module name is added into the query struct before the query-string
      is parsed.  This allows the query-string to be shorter:
      
      instead of:
         $modname.dyndbg="module $modname +fp"
      do this:
         $modname.dyndbg="+fp"
      
      Omitting "module $modname" from the query string is actually required
      for $modname.dyndbg rules; the set-only-once check added in a previous
      patch will throw an error if its added again.  ddebug_query="..." has
      no $modname associated with it, so the query string may include it.
      
      This also fixes redundant "module $modname" otherwise needed to handle
      multiple queries per string:
      
         $modname.dyndbg="func foo +fp; func bar +fp"
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8e59b5cf
    • Jim Cromie's avatar
      dynamic_debug: print ram usage by ddebug tables if verbose · 41076927
      Jim Cromie authored
      Print ram usage of dynamic-debug tables and verbose section so user
      knows cost of enabling CONFIG_DYNAMIC_DEBUG.  This only counts the
      size of the _ddebug tables for builtins and the __verbose section that
      they refer to, not those used in loadable modules.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      41076927
    • Jim Cromie's avatar
      dynamic_debug: simplify dynamic_debug_init error exit · af442399
      Jim Cromie authored
      We dont want errors while parsing ddebug_query to unload ddebug
      tables, so set success after tables are loaded, and return 0 after
      query parsing is done.
      
      Simplify error handling code since its no longer used for success,
      and change goto label to out_err to clarify this.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      af442399
    • Jim Cromie's avatar
      dynamic_debug: combine parse_args callbacks together · 6ab676e9
      Jim Cromie authored
      Refactor ddebug_dyndbg_boot_param_cb and ddebug_dyndbg_module_param_cb
      into a common helper function, and call it from both.  The handling of
      foo.dyndbg is unneeded by the latter, but harmless.
      
      The 2 callers differ only by pr_info and the return code they pass to
      the helper for when an unknown param is handled.  I could slightly
      reduce dmesg clutter by putting the vpr_info in the common helper,
      after the return on_err, but that loses __func__ context, is overly
      silent on module_cb unknown param errors, and the clutter is only when
      dynamic_debug.verbose=1 anyway.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6ab676e9
    • Jim Cromie's avatar
      dynamic_debug: deprecate ddebug_query, suggest dyndbg instead · f0b919d9
      Jim Cromie authored
      With ddebug_dyndbg_boot_params_cb() handling bare dyndbg params, we
      dont need ddebug_query param anymore.  Add a warning when processing
      ddebug_query= param that it is deprecated, and to change it to dyndbg=
      
      Add a deprecation notice for v3.8 to feature-removal-schedule.txt, and
      add a suggested deprecation period of 3 releases to the header.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f0b919d9
    • Jim Cromie's avatar
      dynamic_debug: make dynamic-debug work for module initialization · b48420c1
      Jim Cromie authored
      This introduces a fake module param $module.dyndbg.  Its based upon
      Thomas Renninger's $module.ddebug boot-time debugging patch from
      https://lkml.org/lkml/2010/9/15/397
      
      The 'fake' module parameter is provided for all modules, whether or
      not they need it.  It is not explicitly added to each module, but is
      implemented in callbacks invoked from parse_args.
      
      For builtin modules, dynamic_debug_init() now directly calls
      parse_args(..., &ddebug_dyndbg_boot_params_cb), to process the params
      undeclared in the modules, just after the ddebug tables are processed.
      
      While its slightly weird to reprocess the boot params, parse_args() is
      already called repeatedly by do_initcall_levels().  More importantly,
      the dyndbg queries (given in ddebug_query or dyndbg params) cannot be
      activated until after the ddebug tables are ready, and reusing
      parse_args is cleaner than doing an ad-hoc parse.  This reparse would
      break options like inc_verbosity, but they probably should be params,
      like verbosity=3.
      
      ddebug_dyndbg_boot_params_cb() handles both bare dyndbg (aka:
      ddebug_query) and module-prefixed dyndbg params, and ignores all other
      parameters.  For example, the following will enable pr_debug()s in 4
      builtin modules, in the order given:
      
        dyndbg="module params +p; module aio +p" module.dyndbg=+p pci.dyndbg
      
      For loadable modules, parse_args() in load_module() calls
      ddebug_dyndbg_module_params_cb().  This handles bare dyndbg params as
      passed from modprobe, and errors on other unknown params.
      
      Note that modprobe reads /proc/cmdline, so "modprobe foo" grabs all
      foo.params, strips the "foo.", and passes these to the kernel.
      ddebug_dyndbg_module_params_cb() is again called for the unknown
      params; it handles dyndbg, and errors on others.  The "doing" arg
      added previously contains the module name.
      
      For non CONFIG_DYNAMIC_DEBUG builds, the stub function accepts
      and ignores $module.dyndbg params, other unknowns get -ENOENT.
      
      If no param value is given (as in pci.dyndbg example above), "+p" is
      assumed, which enables all pr_debug callsites in the module.
      
      The dyndbg fake parameter is not shown in /sys/module/*/parameters,
      thus it does not use any resources.  Changes to it are made via the
      control file.
      
      Also change pr_info in ddebug_exec_queries to vpr_info,
      no need to see it all the time.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      CC: Thomas Renninger <trenn@suse.de>
      CC: Rusty Russell <rusty@rustcorp.com.au>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b48420c1