Merge branch 'linus' into x86/i8259

TAGS

TAGS

vmlinux*

vmlinux*

!vmlinux.lds.S

!vmlinux.lds.S

!vmlinux.lds.h

System.map

System.map

Module.markers

Module.markers

Module.symvers

Module.symvers

# cscope files

# cscope files

cscope.*

cscope.*

ncscope.*

*.orig

*.orig

*~

*~

	non-block filesystems which provide their own BDI, such as NFS

	non-block filesystems which provide their own BDI, such as NFS

	and FUSE.

	and FUSE.

MAJOR:MINOR-fuseblk

	Value of st_dev on fuseblk filesystems.

default

default

	The default backing dev, used for non-block device backed

	The default backing dev, used for non-block device backed

</sect1>

</sect1>

</chapter>

</chapter>

<chapter id="trylock-functions">

 <title>The trylock Functions</title>

  <para>

   There are functions that try to acquire a lock only once and immediately

   return a value telling about success or failure to acquire the lock.

   They can be used if you need no access to the data protected with the lock

   when some other thread is holding the lock. You should acquire the lock

   later if you then need access to the data protected with the lock.

  </para>

  <para>

    <function>spin_trylock()</function> does not spin but returns non-zero if

    it acquires the spinlock on the first try or 0 if not. This function can

    be used in all contexts like <function>spin_lock</function>: you must have

    disabled the contexts that might interrupt you and acquire the spin lock.

  </para>

  <para>

    <function>mutex_trylock()</function> does not suspend your task

    but returns non-zero if it could lock the mutex on the first try

    or 0 if not. This function cannot be safely used in hardware or software

    interrupt contexts despite not sleeping.

  </para>

</chapter>

  <chapter id="Examples">

  <chapter id="Examples">

   <title>Common Examples</title>

   <title>Common Examples</title>

    <para>

    <para>

    runs an instance of gdb against the vmlinux file which contains

    runs an instance of gdb against the vmlinux file which contains

    the symbols (not boot image such as bzImage, zImage, uImage...).

    the symbols (not boot image such as bzImage, zImage, uImage...).

    In gdb the developer specifies the connection parameters and

    In gdb the developer specifies the connection parameters and

    connects to kgdb.  Depending on which kgdb I/O modules exist in

    connects to kgdb.  The type of connection a developer makes with

    the kernel for a given architecture, it may be possible to debug

    gdb depends on the availability of kgdb I/O modules compiled as

    the test machine's kernel with the development machine using a

    builtin's or kernel modules in the test machine's kernel.

    rs232 or ethernet connection.

    </para>

    </para>

  </chapter>

  </chapter>

  <chapter id="CompilingAKernel">

  <chapter id="CompilingAKernel">

  </para>

  </para>

  <para>

  <para>

  IMPORTANT NOTE: Using this option with kgdb over the console

  IMPORTANT NOTE: Using this option with kgdb over the console

  (kgdboc) or kgdb over ethernet (kgdboe) is not supported.

  (kgdboc) is not supported.

  </para>

  </para>

  </sect1>

  </sect1>

  </chapter>

  </chapter>

    (gdb) target remote /dev/ttyS0

    (gdb) target remote /dev/ttyS0

    </programlisting>

    </programlisting>

    <para>

    <para>

    Example (kgdb to a terminal server):

    Example (kgdb to a terminal server on tcp port 2012):

    </para>

    </para>

    <programlisting>

    <programlisting>

    % gdb ./vmlinux

    % gdb ./vmlinux

    (gdb) target remote udp:192.168.2.2:6443

    (gdb) target remote 192.168.2.2:2012

    </programlisting>

    <para>

    Example (kgdb over ethernet):

    </para>

    <programlisting>

    % gdb ./vmlinux

    (gdb) target remote udp:192.168.2.2:6443

    </programlisting>

    </programlisting>

    <para>

    <para>

    Once connected, you can debug a kernel the way you would debug an

    Once connected, you can debug a kernel the way you would debug an

now, but you can do this to mark internal company procedures or just

now, but you can do this to mark internal company procedures or just

point out some special detail about the sign-off. 

point out some special detail about the sign-off. 

If you are a subsystem or branch maintainer, sometimes you need to slightly

modify patches you receive in order to merge them, because the code is not

exactly the same in your tree and the submitters'. If you stick strictly to

rule (c), you should ask the submitter to rediff, but this is a totally

counter-productive waste of time and energy. Rule (b) allows you to adjust

the code, but then it is very impolite to change one submitter's code and

make him endorse your bugs. To solve this problem, it is recommended that

you add a line between the last Signed-off-by header and yours, indicating

the nature of your changes. While there is nothing mandatory about this, it

seems like prepending the description with your mail and/or name, all

enclosed in square brackets, is noticeable enough to make it obvious that

you are responsible for last-minute changes. Example :

	Signed-off-by: Random J Developer <random@developer.example.org>

	[lucky@maintainer.example.org: struct foo moved from foo.c to foo.h]

	Signed-off-by: Lucky K Maintainer <lucky@maintainer.example.org>

This practise is particularly helpful if you maintain a stable branch and

want at the same time to credit the author, track changes, merge the fix,

and protect the submitter from complaints. Note that under no circumstances

can you change the author's identity (the From header), as it is the one

which appears in the changelog.

Special note to back-porters: It seems to be a common and useful practise

to insert an indication of the origin of a patch at the top of the commit

message (just after the subject line) to facilitate tracking. For instance,

here's what we see in 2.6-stable :

    Date:   Tue May 13 19:10:30 2008 +0000

        SCSI: libiscsi regression in 2.6.25: fix nop timer handling

        commit 4cf1043593db6a337f10e006c23c69e5fc93e722 upstream

And here's what appears in 2.4 :

    Date:   Tue May 13 22:12:27 2008 +0200

        wireless, airo: waitbusy() won't delay

        [backport of 2.6 commit b7acbdfbd1f277c1eb23f344f899cfa4cd0bf36a]

Whatever the format, this information provides a valuable help to people

tracking your trees, and to people trying to trouble-shoot bugs in your

tree.

13) When to use Acked-by: and Cc:

13) When to use Acked-by: and Cc: