From c730904b16c7ee6f3bba2d1536621151745fc314 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 7 Nov 2016 17:03:17 -0200 Subject: doc-rst: admin-guide: move bug bisect to a separate file Better organize the admin guide documentation by moving the bug bisect to a separate file. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/bug-bisect.rst | 78 ++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 Documentation/admin-guide/bug-bisect.rst (limited to 'Documentation/admin-guide/bug-bisect.rst') diff --git a/Documentation/admin-guide/bug-bisect.rst b/Documentation/admin-guide/bug-bisect.rst new file mode 100644 index 000000000000..5682d742017c --- /dev/null +++ b/Documentation/admin-guide/bug-bisect.rst @@ -0,0 +1,78 @@ +Bisecting a bug ++++++++++++++++ + +Last updated: 28 October 2016 + +Introduction +============ + +Always try the latest kernel from kernel.org and build from source. If you are +not confident in doing that please report the bug to your distribution vendor +instead of to a kernel developer. + +Finding bugs is not always easy. Have a go though. If you can't find it don't +give up. Report as much as you have found to the relevant maintainer. See +MAINTAINERS for who that is for the subsystem you have worked on. + +Before you submit a bug report read +:ref:`Documentation/admin-guide/reporting-bugs.rst `. + +Devices not appearing +===================== + +Often this is caused by udev/systemd. Check that first before blaming it +on the kernel. + +Finding patch that caused a bug +=============================== + +Using the provided tools with ``git`` makes finding bugs easy provided the bug +is reproducible. + +Steps to do it: + +- build the Kernel from its git source +- start bisect with [#f1]_:: + + $ git bisect start + +- mark the broken changeset with:: + + $ git bisect bad [commit] + +- mark a changeset where the code is known to work with:: + + $ git bisect good [commit] + +- rebuild the Kernel and test +- interact with git bisect by using either:: + + $ git bisect good + + or:: + + $ git bisect bad + + depending if the bug happened on the changeset you're testing +- After some interactions, git bisect will give you the changeset that + likely caused the bug. + +- For example, if you know that the current version is bad, and version + 4.8 is good, you could do:: + + $ git bisect start + $ git bisect bad # Current version is bad + $ git bisect good v4.8 + + +.. [#f1] You can, optionally, provide both good and bad arguments at git + start:: + + git bisect start [BAD] [GOOD] + +For further references, please read: + +- The man page for ``git-bisect`` +- `Fighting regressions with git bisect `_ +- `Fully automated bisecting with "git bisect run" `_ +- `Using Git bisect to figure out when brokenness was introduced `_ -- cgit v1.2.3