Enjoy!
+.. note::
+
+ The documents on each section of this document are ordered by its
+ published date, from the newest to the oldest.
+
Docs at the Linux Kernel tree
-----------------------------
On-line docs
------------
- * Title: **Linux Device Drivers, Third Edition**
-
- :Author: Jonathan Corbet, Alessandro Rubini, Greg Kroah-Hartman
- :URL: http://lwn.net/Kernel/LDD3/
- :Date: 2005
- :Description: A 600-page book covering the (2.6.10) driver
- programming API and kernel hacking in general. Available under the
- Creative Commons Attribution-ShareAlike 2.0 license.
- :note: You can also :ref:`purchase a copy from O'Reilly or elsewhere <ldd3_published>`.
-
- * Title: **Overview of the Virtual File System**
-
- :Author: Richard Gooch.
- :URL: http://www.mjmwired.net/kernel/Documentation/filesystems/vfs.txt
- :Date: 2007
- :Keywords: VFS, File System, mounting filesystems, opening files,
- dentries, dcache.
- :Description: Brief introduction to the Linux Virtual File System.
- What is it, how it works, operations taken when opening a file or
- mounting a file system and description of important data
- structures explaining the purpose of each of their entries.
-
- * Title: **The Linux RAID-1, 4, 5 Code**
-
- :Author: Ingo Molnar, Gadi Oxman and Miguel de Icaza.
- :URL: http://www.linuxjournal.com/article.php?sid=2391
- :Date: 1997
- :Keywords: RAID, MD driver.
- :Description: Linux Journal Kernel Korner article. Here is its
- :Abstract: *A description of the implementation of the RAID-1,
- RAID-4 and RAID-5 personalities of the MD device driver in the
- Linux kernel, providing users with high performance and reliable,
- secondary-storage capability using software*.
-
- * Title: **Dynamic Kernels: Modularized Device Drivers**
-
- :Author: Alessandro Rubini.
- :URL: http://www.linuxjournal.com/article.php?sid=1219
- :Date: 1996
- :Keywords: device driver, module, loading/unloading modules,
- allocating resources.
- :Description: Linux Journal Kernel Korner article. Here is its
- :Abstract: *This is the first of a series of four articles
- co-authored by Alessandro Rubini and Georg Zezchwitz which present
- a practical approach to writing Linux device drivers as kernel
- loadable modules. This installment presents an introduction to the
- topic, preparing the reader to understand next month's
- installment*.
-
- * Title: **Dynamic Kernels: Discovery**
-
- :Author: Alessandro Rubini.
- :URL: http://www.linuxjournal.com/article.php?sid=1220
- :Date: 1996
- :Keywords: character driver, init_module, clean_up module,
- autodetection, mayor number, minor number, file operations,
- open(), close().
- :Description: Linux Journal Kernel Korner article. Here is its
- :Abstract: *This article, the second of four, introduces part of
- the actual code to create custom module implementing a character
- device driver. It describes the code for module initialization and
- cleanup, as well as the open() and close() system calls*.
-
- * Title: **On submitting kernel Patches**
+ * Title: **Linux Kernel Mailing List Glossary**
- :Author: Andi Kleen
- :URL: http://halobates.de/on-submitting-kernel-patches.pdf
- :Date: 2008
- :Keywords: patches, review process, types of submissions, basic rules, case studies
- :Description: This paper gives several experience values on what types of patches
- there are and how likley they get merged.
- :Abstract:
- [...]. This paper examines some common problems for
- submitting larger changes and some strategies to avoid problems.
+ :Author: various
+ :URL: http://kernelnewbies.org/glossary/
+ :Date: rolling version
+ :Keywords: glossary, terms, linux-kernel.
+ :Description: From the introduction: "This glossary is intended as
+ a brief description of some of the acronyms and terms you may hear
+ during discussion of the Linux kernel".
* Title: **Tracing the Way of Data in a TCP Connection through the Linux Kernel**
+
:Author: Richard Sailer
:URL: https://archive.org/details/linux_kernel_data_flow_short_paper
:Date: 2016
Finally this trace-log is used as base for more a exact conceptual
exploration and description of the Linux TCP/IP implementation.*
- * Title: **The Devil's in the Details**
-
- :Author: Georg v. Zezschwitz and Alessandro Rubini.
- :URL: http://www.linuxjournal.com/article.php?sid=1221
- :Date: 1996
- :Keywords: read(), write(), select(), ioctl(), blocking/non
- blocking mode, interrupt handler.
- :Description: Linux Journal Kernel Korner article. Here is its
- :Abstract: *This article, the third of four on writing character
- device drivers, introduces concepts of reading, writing, and using
- ioctl-calls*.
-
- * Title: **Dissecting Interrupts and Browsing DMA**
-
- :Author: Alessandro Rubini and Georg v. Zezschwitz.
- :URL: http://www.linuxjournal.com/article.php?sid=1222
- :Date: 1996
- :Keywords: interrupts, irqs, DMA, bottom halves, task queues.
- :Description: Linux Journal Kernel Korner article. Here is its
- :Abstract: *This is the fourth in a series of articles about
- writing character device drivers as loadable kernel modules. This
- month, we further investigate the field of interrupt handling.
- Though it is conceptually simple, practical limitations and
- constraints make this an ''interesting'' part of device driver
- writing, and several different facilities have been provided for
- different situations. We also investigate the complex topic of
- DMA*.
-
- * Title: **Device Drivers Concluded**
-
- :Author: Georg v. Zezschwitz.
- :URL: http://www.linuxjournal.com/article.php?sid=1287
- :Date: 1996
- :Keywords: address spaces, pages, pagination, page management,
- demand loading, swapping, memory protection, memory mapping, mmap,
- virtual memory areas (VMAs), vremap, PCI.
- :Description: Finally, the above turned out into a five articles
- series. This latest one's introduction reads: "This is the last of
- five articles about character device drivers. In this final
- section, Georg deals with memory mapping devices, beginning with
- an overall description of the Linux memory management concepts".
-
- * Title: **Network Buffers And Memory Management**
+ * Title: **On submitting kernel Patches**
- :Author: Alan Cox.
- :URL: http://www.linuxjournal.com/article.php?sid=1312
- :Date: 1996
- :Keywords: sk_buffs, network devices, protocol/link layer
- variables, network devices flags, transmit, receive,
- configuration, multicast.
- :Description: Linux Journal Kernel Korner.
- :Abstract: *Writing a network device driver for Linux is fundamentally
- simple---most of the complexity (other than talking to the
- hardware) involves managing network packets in memory*.
+ :Author: Andi Kleen
+ :URL: http://halobates.de/on-submitting-kernel-patches.pdf
+ :Date: 2008
+ :Keywords: patches, review process, types of submissions, basic rules, case studies
+ :Description: This paper gives several experience values on what types of patches
+ there are and how likley they get merged.
+ :Abstract:
+ [...]. This paper examines some common problems for
+ submitting larger changes and some strategies to avoid problems.
- * Title: **Linux Kernel Hackers' Guide**
+ * Title: **Overview of the Virtual File System**
- :Author: Michael K. Johnson.
- :URL: http://www.tldp.org/LDP/khg/HyperNews/get/khg.html
- :Date: 1997
- :Keywords: device drivers, files, VFS, kernel interface, character vs
- block devices, hardware interrupts, scsi, DMA, access to user memory,
- memory allocation, timers.
- :Description: A guide designed to help you get up to speed on the
- concepts that are not intuitevly obvious, and to document the internal
- structures of Linux.
+ :Author: Richard Gooch.
+ :URL: http://www.mjmwired.net/kernel/Documentation/filesystems/vfs.txt
+ :Date: 2007
+ :Keywords: VFS, File System, mounting filesystems, opening files,
+ dentries, dcache.
+ :Description: Brief introduction to the Linux Virtual File System.
+ What is it, how it works, operations taken when opening a file or
+ mounting a file system and description of important data
+ structures explaining the purpose of each of their entries.
- * Title: **The Venus kernel interface**
+ * Title: **Linux Device Drivers, Third Edition**
- :Author: Peter J. Braam.
- :URL: http://www.coda.cs.cmu.edu/doc/html/kernel-venus-protocol.html
- :Date: 1998
- :Keywords: coda, filesystem, venus, cache manager.
- :Description: "This document describes the communication between
- Venus and kernel level file system code needed for the operation
- of the Coda filesystem. This version document is meant to describe
- the current interface (version 1.0) as well as improvements we
- envisage".
+ :Author: Jonathan Corbet, Alessandro Rubini, Greg Kroah-Hartman
+ :URL: http://lwn.net/Kernel/LDD3/
+ :Date: 2005
+ :Description: A 600-page book covering the (2.6.10) driver
+ programming API and kernel hacking in general. Available under the
+ Creative Commons Attribution-ShareAlike 2.0 license.
+ :note: You can also :ref:`purchase a copy from O'Reilly or elsewhere <ldd3_published>`.
- * Title: **Design and Implementation of the Second Extended Filesystem**
+ * Title: **Writing an ALSA Driver**
- :Author: Rémy Card, Theodore Ts'o, Stephen Tweedie.
- :URL: http://web.mit.edu/tytso/www/linux/ext2intro.html
- :Date: 1998
- :Keywords: ext2, linux fs history, inode, directory, link, devices,
- VFS, physical structure, performance, benchmarks, ext2fs library,
- ext2fs tools, e2fsck.
- :Description: Paper written by three of the top ext2 hackers.
- Covers Linux filesystems history, ext2 motivation, ext2 features,
- design, physical structure on disk, performance, benchmarks,
- e2fsck's passes description... A must read!
- :Notes: This paper was first published in the Proceedings of the
- First Dutch International Symposium on Linux, ISBN 90-367-0385-9.
+ :Author: Takashi Iwai <tiwai@suse.de>
+ :URL: http://www.alsa-project.org/~iwai/writing-an-alsa-driver/index.html
+ :Date: 2005
+ :Keywords: ALSA, sound, soundcard, driver, lowlevel, hardware.
+ :Description: Advanced Linux Sound Architecture for developers,
+ both at kernel and user-level sides. ALSA is the Linux kernel
+ sound architecture in the 2.6 kernel version.
- * Title: **Analysis of the Ext2fs structure**
+ * Title: **Linux PCMCIA Programmer's Guide**
- :Author: Louis-Dominique Dubeau.
- :URL: http://teaching.csse.uwa.edu.au/units/CITS2002/fs-ext2/
- :Date: 1994
- :Keywords: ext2, filesystem, ext2fs.
- :Description: Description of ext2's blocks, directories, inodes,
- bitmaps, invariants...
+ :Author: David Hinds.
+ :URL: http://pcmcia-cs.sourceforge.net/ftp/doc/PCMCIA-PROG.html
+ :Date: 2003
+ :Keywords: PCMCIA.
+ :Description: "This document describes how to write kernel device
+ drivers for the Linux PCMCIA Card Services interface. It also
+ describes how to write user-mode utilities for communicating with
+ Card Services.
* Title: **Linux Kernel Module Programming Guide**
:Description: Very nice 92 pages GPL book on the topic of modules
programming. Lots of examples.
- * Title: **I/O Event Handling Under Linux**
-
- :Author: Richard Gooch.
- :URL: http://web.mit.edu/~yandros/doc/io-events.html
- :Date: 1999
- :Keywords: IO, I/O, select(2), poll(2), FDs, aio_read(2), readiness
- event queues.
- :Description: From the Introduction: "I/O Event handling is about
- how your Operating System allows you to manage a large number of
- open files (file descriptors in UNIX/POSIX, or FDs) in your
- application. You want the OS to notify you when FDs become active
- (have data ready to be read or are ready for writing). Ideally you
- want a mechanism that is scalable. This means a large number of
- inactive FDs cost very little in memory and CPU time to manage".
-
- * Title: **Writing an ALSA Driver**
-
- :Author: Takashi Iwai <tiwai@suse.de>
- :URL: http://www.alsa-project.org/~iwai/writing-an-alsa-driver/index.html
- :Date: 2005
- :Keywords: ALSA, sound, soundcard, driver, lowlevel, hardware.
- :Description: Advanced Linux Sound Architecture for developers,
- both at kernel and user-level sides. ALSA is the Linux kernel
- sound architecture in the 2.6 kernel version.
-
- * Title: **Linux Kernel Mailing List Glossary**
-
- :Author: various
- :URL: http://kernelnewbies.org/glossary/
- :Date: rolling version
- :Keywords: glossary, terms, linux-kernel.
- :Description: From the introduction: "This glossary is intended as
- a brief description of some of the acronyms and terms you may hear
- during discussion of the Linux kernel".
-
* Title: **Global spinlock list and usage**
:Author: Rick Lindsley.
access them, how each lock is acquired, under what conditions it
is held, whether interrupts can occur or not while it is held...
+ * Title: **A Linux vm README**
+
+ :Author: Kanoj Sarcar.
+ :URL: http://kos.enix.org/pub/linux-vmm.html
+ :Date: 2001
+ :Keywords: virtual memory, mm, pgd, vma, page, page flags, page
+ cache, swap cache, kswapd.
+ :Description: Telegraphic, short descriptions and definitions
+ relating the Linux virtual memory implementation.
+
+ * Title: **Video4linux Drivers, Part 1: Video-Capture Device**
+
+ :Author: Alan Cox.
+ :URL: http://www.linux-mag.com/id/406
+ :Date: 2000
+ :Keywords: video4linux, driver, video capture, capture devices,
+ camera driver.
+ :Description: The title says it all.
+
+ * Title: **Video4linux Drivers, Part 2: Video-capture Devices**
+
+ :Author: Alan Cox.
+ :URL: http://www.linux-mag.com/id/429
+ :Date: 2000
+ :Keywords: video4linux, driver, video capture, capture devices,
+ camera driver, control, query capabilities, capability, facility.
+ :Description: The title says it all.
+
+ * Title: **Linux IP Networking. A Guide to the Implementation and Modification of the Linux Protocol Stack.**
+
+ :Author: Glenn Herrin.
+ :URL: http://www.cs.unh.edu/cnrg/gherrin
+ :Date: 2000
+ :Keywords: network, networking, protocol, IP, UDP, TCP, connection,
+ socket, receiving, transmitting, forwarding, routing, packets,
+ modules, /proc, sk_buff, FIB, tags.
+ :Description: Excellent paper devoted to the Linux IP Networking,
+ explaining anything from the kernel's to the user space
+ configuration tools' code. Very good to get a general overview of
+ the kernel networking implementation and understand all steps
+ packets follow from the time they are received at the network
+ device till they are delivered to applications. The studied kernel
+ code is from 2.2.14 version. Provides code for a working packet
+ dropper example.
+
* Title: **How To Make Sure Your Driver Will Work On The Power Macintosh**
:Author: Paul Mackerras.
:Keywords: video4linux, driver, radio, radio devices.
:Description: The title says it all.
- * Title: **Video4linux Drivers, Part 1: Video-Capture Device**
-
- :Author: Alan Cox.
- :URL: http://www.linux-mag.com/id/406
- :Date: 2000
- :Keywords: video4linux, driver, video capture, capture devices,
- camera driver.
- :Description: The title says it all.
-
- * Title: **Video4linux Drivers, Part 2: Video-capture Devices**
-
- :Author: Alan Cox.
- :URL: http://www.linux-mag.com/id/429
- :Date: 2000
- :Keywords: video4linux, driver, video capture, capture devices,
- camera driver, control, query capabilities, capability, facility.
- :Description: The title says it all.
-
- * Title: **Linux IP Networking. A Guide to the Implementation and Modification of the Linux Protocol Stack.**
-
- :Author: Glenn Herrin.
- :URL: http://www.cs.unh.edu/cnrg/gherrin
- :Date: 2000
- :Keywords: network, networking, protocol, IP, UDP, TCP, connection,
- socket, receiving, transmitting, forwarding, routing, packets,
- modules, /proc, sk_buff, FIB, tags.
- :Description: Excellent paper devoted to the Linux IP Networking,
- explaining anything from the kernel's to the user space
- configuration tools' code. Very good to get a general overview of
- the kernel networking implementation and understand all steps
- packets follow from the time they are received at the network
- device till they are delivered to applications. The studied kernel
- code is from 2.2.14 version. Provides code for a working packet
- dropper example.
-
- * Title: **Linux PCMCIA Programmer's Guide**
-
- :Author: David Hinds.
- :URL: http://pcmcia-cs.sourceforge.net/ftp/doc/PCMCIA-PROG.html
- :Date: 2003
- :Keywords: PCMCIA.
- :Description: "This document describes how to write kernel device
- drivers for the Linux PCMCIA Card Services interface. It also
- describes how to write user-mode utilities for communicating with
- Card Services.
-
- * Title: **A Linux vm README**
+ * Title: **I/O Event Handling Under Linux**
- :Author: Kanoj Sarcar.
- :URL: http://kos.enix.org/pub/linux-vmm.html
- :Date: 2001
- :Keywords: virtual memory, mm, pgd, vma, page, page flags, page
- cache, swap cache, kswapd.
- :Description: Telegraphic, short descriptions and definitions
- relating the Linux virtual memory implementation.
+ :Author: Richard Gooch.
+ :URL: http://web.mit.edu/~yandros/doc/io-events.html
+ :Date: 1999
+ :Keywords: IO, I/O, select(2), poll(2), FDs, aio_read(2), readiness
+ event queues.
+ :Description: From the Introduction: "I/O Event handling is about
+ how your Operating System allows you to manage a large number of
+ open files (file descriptors in UNIX/POSIX, or FDs) in your
+ application. You want the OS to notify you when FDs become active
+ (have data ready to be read or are ready for writing). Ideally you
+ want a mechanism that is scalable. This means a large number of
+ inactive FDs cost very little in memory and CPU time to manage".
* Title: **(nearly) Complete Linux Loadable Kernel Modules. The definitive guide for hackers, virus coders and system administrators.**
Linux VFS layer. Covers version 2.1.x, with dentries and the
dcache.
-.. Please keep the published books in reverse publication date
+ * Title: **The Venus kernel interface**
+
+ :Author: Peter J. Braam.
+ :URL: http://www.coda.cs.cmu.edu/doc/html/kernel-venus-protocol.html
+ :Date: 1998
+ :Keywords: coda, filesystem, venus, cache manager.
+ :Description: "This document describes the communication between
+ Venus and kernel level file system code needed for the operation
+ of the Coda filesystem. This version document is meant to describe
+ the current interface (version 1.0) as well as improvements we
+ envisage".
+
+ * Title: **Design and Implementation of the Second Extended Filesystem**
+
+ :Author: Rémy Card, Theodore Ts'o, Stephen Tweedie.
+ :URL: http://web.mit.edu/tytso/www/linux/ext2intro.html
+ :Date: 1998
+ :Keywords: ext2, linux fs history, inode, directory, link, devices,
+ VFS, physical structure, performance, benchmarks, ext2fs library,
+ ext2fs tools, e2fsck.
+ :Description: Paper written by three of the top ext2 hackers.
+ Covers Linux filesystems history, ext2 motivation, ext2 features,
+ design, physical structure on disk, performance, benchmarks,
+ e2fsck's passes description... A must read!
+ :Notes: This paper was first published in the Proceedings of the
+ First Dutch International Symposium on Linux, ISBN 90-367-0385-9.
+
+ * Title: **The Linux RAID-1, 4, 5 Code**
+
+ :Author: Ingo Molnar, Gadi Oxman and Miguel de Icaza.
+ :URL: http://www.linuxjournal.com/article.php?sid=2391
+ :Date: 1997
+ :Keywords: RAID, MD driver.
+ :Description: Linux Journal Kernel Korner article. Here is its
+ :Abstract: *A description of the implementation of the RAID-1,
+ RAID-4 and RAID-5 personalities of the MD device driver in the
+ Linux kernel, providing users with high performance and reliable,
+ secondary-storage capability using software*.
+
+ * Title: **Linux Kernel Hackers' Guide**
+
+ :Author: Michael K. Johnson.
+ :URL: http://www.tldp.org/LDP/khg/HyperNews/get/khg.html
+ :Date: 1997
+ :Keywords: device drivers, files, VFS, kernel interface, character vs
+ block devices, hardware interrupts, scsi, DMA, access to user memory,
+ memory allocation, timers.
+ :Description: A guide designed to help you get up to speed on the
+ concepts that are not intuitevly obvious, and to document the internal
+ structures of Linux.
+
+ * Title: **Dynamic Kernels: Modularized Device Drivers**
+
+ :Author: Alessandro Rubini.
+ :URL: http://www.linuxjournal.com/article.php?sid=1219
+ :Date: 1996
+ :Keywords: device driver, module, loading/unloading modules,
+ allocating resources.
+ :Description: Linux Journal Kernel Korner article. Here is its
+ :Abstract: *This is the first of a series of four articles
+ co-authored by Alessandro Rubini and Georg Zezchwitz which present
+ a practical approach to writing Linux device drivers as kernel
+ loadable modules. This installment presents an introduction to the
+ topic, preparing the reader to understand next month's
+ installment*.
+
+ * Title: **Dynamic Kernels: Discovery**
+
+ :Author: Alessandro Rubini.
+ :URL: http://www.linuxjournal.com/article.php?sid=1220
+ :Date: 1996
+ :Keywords: character driver, init_module, clean_up module,
+ autodetection, mayor number, minor number, file operations,
+ open(), close().
+ :Description: Linux Journal Kernel Korner article. Here is its
+ :Abstract: *This article, the second of four, introduces part of
+ the actual code to create custom module implementing a character
+ device driver. It describes the code for module initialization and
+ cleanup, as well as the open() and close() system calls*.
+
+ * Title: **The Devil's in the Details**
+
+ :Author: Georg v. Zezschwitz and Alessandro Rubini.
+ :URL: http://www.linuxjournal.com/article.php?sid=1221
+ :Date: 1996
+ :Keywords: read(), write(), select(), ioctl(), blocking/non
+ blocking mode, interrupt handler.
+ :Description: Linux Journal Kernel Korner article. Here is its
+ :Abstract: *This article, the third of four on writing character
+ device drivers, introduces concepts of reading, writing, and using
+ ioctl-calls*.
+
+ * Title: **Dissecting Interrupts and Browsing DMA**
+
+ :Author: Alessandro Rubini and Georg v. Zezschwitz.
+ :URL: http://www.linuxjournal.com/article.php?sid=1222
+ :Date: 1996
+ :Keywords: interrupts, irqs, DMA, bottom halves, task queues.
+ :Description: Linux Journal Kernel Korner article. Here is its
+ :Abstract: *This is the fourth in a series of articles about
+ writing character device drivers as loadable kernel modules. This
+ month, we further investigate the field of interrupt handling.
+ Though it is conceptually simple, practical limitations and
+ constraints make this an ''interesting'' part of device driver
+ writing, and several different facilities have been provided for
+ different situations. We also investigate the complex topic of
+ DMA*.
+
+ * Title: **Device Drivers Concluded**
+
+ :Author: Georg v. Zezschwitz.
+ :URL: http://www.linuxjournal.com/article.php?sid=1287
+ :Date: 1996
+ :Keywords: address spaces, pages, pagination, page management,
+ demand loading, swapping, memory protection, memory mapping, mmap,
+ virtual memory areas (VMAs), vremap, PCI.
+ :Description: Finally, the above turned out into a five articles
+ series. This latest one's introduction reads: "This is the last of
+ five articles about character device drivers. In this final
+ section, Georg deals with memory mapping devices, beginning with
+ an overall description of the Linux memory management concepts".
+
+ * Title: **Network Buffers And Memory Management**
+
+ :Author: Alan Cox.
+ :URL: http://www.linuxjournal.com/article.php?sid=1312
+ :Date: 1996
+ :Keywords: sk_buffs, network devices, protocol/link layer
+ variables, network devices flags, transmit, receive,
+ configuration, multicast.
+ :Description: Linux Journal Kernel Korner.
+ :Abstract: *Writing a network device driver for Linux is fundamentally
+ simple---most of the complexity (other than talking to the
+ hardware) involves managing network packets in memory*.
+
+ * Title: **Analysis of the Ext2fs structure**
+
+ :Author: Louis-Dominique Dubeau.
+ :URL: http://teaching.csse.uwa.edu.au/units/CITS2002/fs-ext2/
+ :Date: 1994
+ :Keywords: ext2, filesystem, ext2fs.
+ :Description: Description of ext2's blocks, directories, inodes,
+ bitmaps, invariants...
Published books
---------------
:Author: Bill O. Gallmeister
:Publisher: O'Reilly & Associates, Inc
:Date: 1995
- :Pages: ???
+ :Pages: 552
:ISBN: I-56592-074-0
:Notes: Though not being directly about Linux, Linux aims to be
POSIX. Good reference.
-------
-Document last updated on Mon 2016-Sep-19
+Document last updated on Tue 2016-Sep-20
This document is based on:
http://www.dit.upm.es/~jmseyas/linux/kernel/hackers-docs.html
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff