with "the system." This text is a collection of suggestions which
can greatly increase the chances of your change being accepted.
-If you are submitting a driver, also read Documentation/SubmittingDrivers.
+Read Documentation/SubmitChecklist for a list of items to check
+before submitting code. If you are submitting a driver, also read
+Documentation/SubmittingDrivers.
To create a patch for a single file, it is often sufficient to do:
- SRCTREE= linux-2.4
+ SRCTREE= linux-2.6
MYFILE= drivers/net/mydriver.c
cd $SRCTREE
or unmodified kernel source tree, and generate a diff against your
own source tree. For example:
- MYSRC= /devel/linux-2.4
+ MYSRC= /devel/linux-2.6
- tar xvfz linux-2.4.0-test11.tar.gz
- mv linux linux-vanilla
- wget http://www.moses.uklinux.net/patches/dontdiff
- diff -uprN -X dontdiff linux-vanilla $MYSRC > /tmp/patch
- rm -f dontdiff
+ tar xvfz linux-2.6.12.tar.gz
+ mv linux-2.6.12 linux-2.6.12-vanilla
+ diff -uprN -X linux-2.6.12-vanilla/Documentation/dontdiff \
+ linux-2.6.12-vanilla $MYSRC > /tmp/patch
"dontdiff" is a list of files which are generated by the kernel during
the build process, and should be ignored in any diff(1)-generated
-patch. dontdiff is maintained by Tigran Aivazian <tigran@veritas.com>
+patch. The "dontdiff" file is included in the kernel tree in
+2.6.12 and later. For earlier kernel versions, you can get it
+from <http://www.xenotime.net/linux/doc/dontdiff>.
Make sure your patch does not include any extra files which do not
belong in a patch submission. Make sure to review your patch -after-
If your changes produce a lot of deltas, you may want to look into
splitting them into individual patches which modify things in
-logical stages, this will facilitate easier reviewing by other
+logical stages. This will facilitate easier reviewing by other
kernel developers, very important if you want your patch accepted.
-There are a number of scripts which can aid in this;
+There are a number of scripts which can aid in this:
Quilt:
http://savannah.nongnu.org/projects/quilt
-Randy Dunlap's patch scripts:
-http://developer.osdl.org/rddunlap/scripts/patching-scripts.tgz
-
Andrew Morton's patch scripts:
-http://www.zip.com.au/~akpm/linux/patches/patch-scripts-0.16
+http://www.zip.com.au/~akpm/linux/patches/
+Instead of these scripts, quilt is the recommended patch management
+tool (see above).
+
+
2) Describe your changes.
3) Separate your changes.
-Separate each logical change into its own patch.
+Separate _logical changes_ into a single patch file.
For example, if your changes include both bug fixes and performance
enhancements for a single driver, separate those changes into two
complete, that is OK. Simply note "this patch depends on patch X"
in your patch description.
+If you cannot condense your patch set into a smaller set of patches,
+then only post say 15 or so at a time and wait for review and integration.
+
+
4) Select e-mail destination.
linux-kernel@vger.kernel.org. Most kernel developers monitor this
e-mail list, and can comment on your changes.
+
+Do not send more than 15 patches at once to the vger mailing lists!!!
+
+
Linus Torvalds is the final arbiter of all changes accepted into the
Linux kernel. His e-mail address is <torvalds@osdl.org>. He gets
a lot of e-mail, so typically you should do your best to -avoid- sending
usually be sent first to linux-kernel. Only after the patch is
discussed should the patch then be submitted to Linus.
-For small patches you may want to CC the Trivial Patch Monkey
-trivial@rustcorp.com.au set up by Rusty Russell; which collects "trivial"
-patches. Trivial patches must qualify for one of the following rules:
- Spelling fixes in documentation
- Spelling fixes which could break grep(1).
- Warning fixes (cluttering with useless warnings is bad)
- Compilation fixes (only if they are actually correct)
- Runtime fixes (only if they actually fix things)
- Removing use of deprecated functions/macros (eg. check_region).
- Contact detail and documentation fixes
- Non-portable code replaced by portable code (even in arch-specific,
- since people copy, as long as it's trivial)
- Any fix by the author/maintainer of the file. (ie. patch monkey
- in re-transmission mode)
-
5) Select your CC (e-mail carbon copy) list.
MAINTAINERS file for a mailing list that relates specifically to
your change.
+Majordomo lists of VGER.KERNEL.ORG at:
+ <http://vger.kernel.org/vger-lists.html>
+
+If changes affect userland-kernel interfaces, please send
+the MAN-PAGES maintainer (as listed in the MAINTAINERS file)
+a man-pages patch, or at least a notification of the change,
+so that some information makes its way into the manual pages.
+
Even if the maintainer did not respond in step #4, make sure to ALWAYS
copy the maintainer when you change their code.
For small patches you may want to CC the Trivial Patch Monkey
-trivial@rustcorp.com.au set up by Rusty Russell; which collects "trivial"
+trivial@kernel.org managed by Adrian Bunk; which collects "trivial"
patches. Trivial patches must qualify for one of the following rules:
Spelling fixes in documentation
- Spelling fixes which could break grep(1).
+ Spelling fixes which could break grep(1)
Warning fixes (cluttering with useless warnings is bad)
Compilation fixes (only if they are actually correct)
Runtime fixes (only if they actually fix things)
- Removing use of deprecated functions/macros (eg. check_region).
+ Removing use of deprecated functions/macros (eg. check_region)
Contact detail and documentation fixes
Non-portable code replaced by portable code (even in arch-specific,
since people copy, as long as it's trivial)
- Any fix by the author/maintainer of the file. (ie. patch monkey
+ Any fix by the author/maintainer of the file (ie. patch monkey
in re-transmission mode)
+URL: <http://www.kernel.org/pub/linux/kernel/people/bunk/trivial/>
+
you to re-send them using MIME.
+WARNING: Some mailers like Mozilla send your messages with
+---- message header ----
+Content-Type: text/plain; charset=us-ascii; format=flowed
+---- message header ----
+The problem is that "format=flowed" makes some of the mailers
+on receiving side to replace TABs with spaces and do similar
+changes. Thus the patches from you can look corrupted.
+
+To fix this just make your mozilla defaults/pref/mailnews.js file to look like:
+pref("mailnews.send_plaintext_flowed", false); // RFC 2646=======
+pref("mailnews.display.disable_format_flowed_support", true);
+
+
7) E-mail size.
It is quite common for Linus to "drop" your patch without comment.
That's the nature of the system. If he drops your patch, it could be
due to
-* Your patch did not apply cleanly to the latest kernel version
+* Your patch did not apply cleanly to the latest kernel version.
* Your patch was not sufficiently discussed on linux-kernel.
-* A style issue (see section 2),
-* An e-mail formatting issue (re-read this section)
-* A technical problem with your change
-* He gets tons of e-mail, and yours got lost in the shuffle
-* You are being annoying (See Figure 1)
+* A style issue (see section 2).
+* An e-mail formatting issue (re-read this section).
+* A technical problem with your change.
+* He gets tons of e-mail, and yours got lost in the shuffle.
+* You are being annoying.
When in doubt, solicit comments on linux-kernel mailing list.
then you just add a line saying
- Signed-off-by: Random J Developer <random@developer.org>
+ Signed-off-by: Random J Developer <random@developer.example.org>
+
+using your real name (sorry, no pseudonyms or anonymous contributions.)
Some people also put extra tags at the end. They'll just be ignored for
now, but you can do this to mark internal company procedures or just
point out some special detail about the sign-off.
+12) The canonical patch format
+
+The canonical patch subject line is:
+
+ Subject: [PATCH 001/123] subsystem: summary phrase
+
+The canonical patch message body contains the following:
+
+ - A "from" line specifying the patch author.
+
+ - An empty line.
+
+ - The body of the explanation, which will be copied to the
+ permanent changelog to describe this patch.
+
+ - The "Signed-off-by:" lines, described above, which will
+ also go in the changelog.
+
+ - A marker line containing simply "---".
+
+ - Any additional comments not suitable for the changelog.
+
+ - The actual patch (diff output).
+
+The Subject line format makes it very easy to sort the emails
+alphabetically by subject line - pretty much any email reader will
+support that - since because the sequence number is zero-padded,
+the numerical and alphabetic sort is the same.
+
+The "subsystem" in the email's Subject should identify which
+area or subsystem of the kernel is being patched.
+
+The "summary phrase" in the email's Subject should concisely
+describe the patch which that email contains. The "summary
+phrase" should not be a filename. Do not use the same "summary
+phrase" for every patch in a whole patch series.
+
+Bear in mind that the "summary phrase" of your email becomes
+a globally-unique identifier for that patch. It propagates
+all the way into the git changelog. The "summary phrase" may
+later be used in developer discussions which refer to the patch.
+People will want to google for the "summary phrase" to read
+discussion regarding that patch.
+
+A couple of example Subjects:
+
+ Subject: [patch 2/5] ext2: improve scalability of bitmap searching
+ Subject: [PATCHv2 001/207] x86: fix eflags tracking
+
+The "from" line must be the very first line in the message body,
+and has the form:
+
+ From: Original Author <author@example.com>
+
+The "from" line specifies who will be credited as the author of the
+patch in the permanent changelog. If the "from" line is missing,
+then the "From:" line from the email header will be used to determine
+the patch author in the changelog.
+
+The explanation body will be committed to the permanent source
+changelog, so should make sense to a competent reader who has long
+since forgotten the immediate details of the discussion that might
+have led to this patch.
+
+The "---" marker line serves the essential purpose of marking for patch
+handling tools where the changelog message ends.
+
+One good use for the additional comments after the "---" marker is for
+a diffstat, to show what files have changed, and the number of inserted
+and deleted lines per file. A diffstat is especially useful on bigger
+patches. Other comments relevant only to the moment or the maintainer,
+not suitable for the permanent changelog, should also go here.
+Use diffstat options "-p 1 -w 70" so that filenames are listed from the
+top of the kernel source tree and don't use too much horizontal space
+(easily fit in 80 columns, maybe with some indentation).
+
+See more details on the proper patch format in the following
+references.
+
+
+
+
-----------------------------------
SECTION 2 - HINTS, TIPS, AND TRICKS
-----------------------------------
4) Don't over-design.
Don't try to anticipate nebulous future cases which may or may not
-be useful: "Make it as simple as you can, and no simpler"
+be useful: "Make it as simple as you can, and no simpler."
+
+
+
+----------------------
+SECTION 3 - REFERENCES
+----------------------
+
+Andrew Morton, "The perfect patch" (tpp).
+ <http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt>
+
+Jeff Garzik, "Linux kernel patch submission format".
+ <http://linux.yyz.us/patch-format.html>
+
+Greg Kroah-Hartman, "How to piss off a kernel subsystem maintainer".
+ <http://www.kroah.com/log/2005/03/31/>
+ <http://www.kroah.com/log/2005/07/08/>
+ <http://www.kroah.com/log/2005/10/19/>
+ <http://www.kroah.com/log/2006/01/11/>
+NO!!!! No more huge patch bombs to linux-kernel@vger.kernel.org people!
+ <http://marc.theaimsgroup.com/?l=linux-kernel&m=112112749912944&w=2>
+Kernel Documentation/CodingStyle:
+ <http://sosdg.org/~coywolf/lxr/source/Documentation/CodingStyle>
+Linus Torvalds's mail on the canonical patch format:
+ <http://lkml.org/lkml/2005/4/7/183>
+--