From da8395be0bb04f685d55f124d046766d9209214a Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 20 May 2008 22:13:09 -0400 Subject: [CPUFREQ] Remove documentation of removed ondemand tunable. sampling_down_factor was removed in ccb2fe209dac9ff67f6351e783e610073afaaeaf back in June 2006. Signed-off-by: Dave Jones --- Documentation/cpu-freq/governors.txt | 8 -------- 1 file changed, 8 deletions(-) (limited to 'Documentation') diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index 6a9c55b..dcec056 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt @@ -129,14 +129,6 @@ to its default value of '80' it means that between the checking intervals the CPU needs to be on average more than 80% in use to then decide that the CPU frequency needs to be increased. -sampling_down_factor: this parameter controls the rate that the CPU -makes a decision on when to decrease the frequency. When set to its -default value of '5' it means that at 1/5 the sampling_rate the kernel -makes a decision to lower the frequency. Five "lower rate" decisions -have to be made in a row before the CPU frequency is actually lower. -If set to '1' then the frequency decreases as quickly as it increases, -if set to '2' it decreases at half the rate of the increase. - ignore_nice_load: this parameter takes a value of '0' or '1'. When set to '0' (its default), all processes are counted towards the 'cpu utilisation' value. When set to '1', the processes that are -- cgit v1.1 From 4d2e7d0d77e4e1e8a21cc990c607985fdba20e66 Mon Sep 17 00:00:00 2001 From: Matti Linnanvuori Date: Tue, 13 May 2008 18:31:47 +0300 Subject: doc: add a chapter about trylock functions [Bug 9011] Add a chapter about trylock functions. http://bugzilla.kernel.org/show_bug.cgi?id=9011 Signed-off-by: Matti Linnanvuori Signed-off-by: Rusty Russell (removed down_trylock) --- Documentation/DocBook/kernel-locking.tmpl | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'Documentation') diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl index 77c42f4..2510763 100644 --- a/Documentation/DocBook/kernel-locking.tmpl +++ b/Documentation/DocBook/kernel-locking.tmpl @@ -703,6 +703,31 @@ + + The trylock Functions + + 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. + + + + spin_trylock() 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 spin_lock: you must have + disabled the contexts that might interrupt you and acquire the spin lock. + + + + mutex_trylock() 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. + + + Common Examples -- cgit v1.1 From 03fb0bce01490c9bdedad861962c76f987531014 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 23 May 2008 13:04:19 -0700 Subject: fuse: fix bdi naming conflict Fuse allocates a separate bdi for each filesystem, and registers them in sysfs with "MAJOR:MINOR" of sb->s_dev (st_dev). This works fine for anon devices normally used by fuse, but can conflict with an already registered BDI for "fuseblk" filesystems, where sb->s_dev represents a real block device. In particularl this happens if a non-partitioned device is being mounted. Fix by registering with a different name for "fuseblk" filesystems. Thanks to Ioan Ionita for the bug report. Signed-off-by: Miklos Szeredi Reported-by: Ioan Ionita Tested-by: Ioan Ionita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/ABI/testing/sysfs-class-bdi | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 5ac1e01..5f50097 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -14,6 +14,10 @@ MAJOR:MINOR non-block filesystems which provide their own BDI, such as NFS and FUSE. +MAJOR:MINOR-fuseblk + + Value of st_dev on fuseblk filesystems. + default The default backing dev, used for non-block device backed -- cgit v1.1 From 8808a793f052c0a67426a24b961402fa20e92814 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 23 May 2008 13:04:25 -0700 Subject: ibmaem: new driver for power/energy/temp meters in IBM System X hardware This driver reads IBM Active Energy Manager energy/temperature/power sensors on IBM System X hardware. [akpm@linux-foundation.org: fix printk warnings] Signed-off-by: Darrick J. Wong Cc: "Mark M. Hoffman" Cc: Corey Minyard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/hwmon/ibmaem | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 Documentation/hwmon/ibmaem (limited to 'Documentation') diff --git a/Documentation/hwmon/ibmaem b/Documentation/hwmon/ibmaem new file mode 100644 index 0000000..2fefaf5 --- /dev/null +++ b/Documentation/hwmon/ibmaem @@ -0,0 +1,37 @@ +Kernel driver ibmaem +====================== + +Supported systems: + * Any recent IBM System X server with Active Energy Manager support. + This includes the x3350, x3550, x3650, x3655, x3755, x3850 M2, + x3950 M2, and certain HS2x/LS2x/QS2x blades. The IPMI host interface + driver ("ipmi-si") needs to be loaded for this driver to do anything. + Prefix: 'ibmaem' + Datasheet: Not available + +Author: Darrick J. Wong + +Description +----------- + +This driver implements sensor reading support for the energy and power +meters available on various IBM System X hardware through the BMC. All +sensor banks will be exported as platform devices; this driver can talk +to both v1 and v2 interfaces. This driver is completely separate from the +older ibmpex driver. + +The v1 AEM interface has a simple set of features to monitor energy use. +There is a register that displays an estimate of raw energy consumption +since the last BMC reset, and a power sensor that returns average power +use over a configurable interval. + +The v2 AEM interface is a bit more sophisticated, being able to present +a wider range of energy and power use registers, the power cap as +set by the AEM software, and temperature sensors. + +Special Features +---------------- + +The "power_cap" value displays the current system power cap, as set by +the Active Energy Manager software. Setting the power cap from the host +is not currently supported. -- cgit v1.1 From 20887611523e749d99cc7d64ff6c97d27529fbae Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 30 May 2008 15:09:46 -0500 Subject: lguest: notify on empty This is the lguest implementation of the VIRTIO_F_NOTIFY_ON_EMPTY feature. It is currently only published for network devices, but it is turned on for everyone. Signed-off-by: Rusty Russell --- Documentation/lguest/lguest.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 3be8ab2..82fafe0 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -157,6 +157,9 @@ struct virtqueue /* The routine to call when the Guest pings us. */ void (*handle_output)(int fd, struct virtqueue *me); + + /* Outstanding buffers */ + unsigned int inflight; }; /* Remember the arguments to the program so we can "reboot" */ @@ -702,6 +705,7 @@ static unsigned get_vq_desc(struct virtqueue *vq, errx(1, "Looped descriptor"); } while ((i = next_desc(vq, i)) != vq->vring.num); + vq->inflight++; return head; } @@ -719,6 +723,7 @@ static void add_used(struct virtqueue *vq, unsigned int head, int len) /* Make sure buffer is written before we update index. */ wmb(); vq->vring.used->idx++; + vq->inflight--; } /* This actually sends the interrupt for this virtqueue */ @@ -726,8 +731,9 @@ static void trigger_irq(int fd, struct virtqueue *vq) { unsigned long buf[] = { LHREQ_IRQ, vq->config.irq }; - /* If they don't want an interrupt, don't send one. */ - if (vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) + /* If they don't want an interrupt, don't send one, unless empty. */ + if ((vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) + && vq->inflight) return; /* Send the Guest an interrupt tell them we used something up. */ @@ -1107,6 +1113,7 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, vq->next = NULL; vq->last_avail_idx = 0; vq->dev = dev; + vq->inflight = 0; /* Initialize the configuration. */ vq->config.num = num_descs; @@ -1368,6 +1375,7 @@ static void setup_tun_net(const char *arg) /* Tell Guest what MAC address to use. */ add_feature(dev, VIRTIO_NET_F_MAC); + add_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY); set_config(dev, sizeof(conf), &conf); /* We don't need the socket any more; setup is done. */ -- cgit v1.1 From 57c511d8d47caeeae375cb8106662c0bd6a7e7e0 Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Tue, 3 Jun 2008 16:00:01 -0700 Subject: bridge: update URL This patch updates the URL of the bridge homepage. Signed-off-by: Adrian Bunk Signed-off-by: David S. Miller --- Documentation/networking/bridge.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/networking/bridge.txt b/Documentation/networking/bridge.txt index bdae2db..bec69a8 100644 --- a/Documentation/networking/bridge.txt +++ b/Documentation/networking/bridge.txt @@ -1,6 +1,6 @@ In order to use the Ethernet bridging functionality, you'll need the userspace tools. These programs and documentation are available -at http://bridge.sourceforge.net. The download page is +at http://www.linux-foundation.org/en/Net:Bridge. The download page is http://prdownloads.sourceforge.net/bridge. If you still have questions, don't hesitate to post to the mailing list -- cgit v1.1 From 8f9935732930e705cab1936a03418ce01aee979a Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Sun, 25 May 2008 11:45:53 -0300 Subject: V4L/DVB (7932): cx18: mark Compro H900 as fully supported. I always assumed that the Compro H900 could do digital as well, but it turned out that it is an analog-only card. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/video4linux/cx18.txt | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/video4linux/cx18.txt b/Documentation/video4linux/cx18.txt index 077d56e..6842c26 100644 --- a/Documentation/video4linux/cx18.txt +++ b/Documentation/video4linux/cx18.txt @@ -1,7 +1,9 @@ Some notes regarding the cx18 driver for the Conexant CX23418 MPEG encoder chip: -1) The only hardware currently supported is the Hauppauge HVR-1600. +1) The only hardware currently supported is the Hauppauge HVR-1600 + card and the Compro VideoMate H900 (note that this card only + supports analog input, it has no digital tuner!). 2) Some people have problems getting the i2c bus to work. Cause unknown. The symptom is that the eeprom cannot be read and the card is -- cgit v1.1 From a9606ce697ed719071fcccee8591ff033fa5e16d Mon Sep 17 00:00:00 2001 From: Daniel Gimpelevich Date: Tue, 3 Jun 2008 21:29:45 -0300 Subject: V4L/DVB (7990): Fix entry for PowerColor RA 330 and make it run with firmware version 2.7 Signed-off-by: Daniel Gimpelevich Signed-off-by: Mauro Carvalho Chehab --- Documentation/video4linux/CARDLIST.cx88 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/video4linux/CARDLIST.cx88 b/Documentation/video4linux/CARDLIST.cx88 index 5439573..7cf5685 100644 --- a/Documentation/video4linux/CARDLIST.cx88 +++ b/Documentation/video4linux/CARDLIST.cx88 @@ -60,7 +60,7 @@ 59 -> DViCO FusionHDTV 5 PCI nano [18ac:d530] 60 -> Pinnacle Hybrid PCTV [12ab:1788] 61 -> Winfast TV2000 XP Global [107d:6f18] - 62 -> PowerColor Real Angel 330 [14f1:ea3d] + 62 -> PowerColor RA330 [14f1:ea3d] 63 -> Geniatech X8000-MT DVBT [14f1:8852] 64 -> DViCO FusionHDTV DVB-T PRO [18ac:db30] 65 -> DViCO FusionHDTV 7 Gold [18ac:d610] -- cgit v1.1 From adbd5886da5f467148b26cca3728ab0e672b3fcc Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Tue, 3 Jun 2008 00:20:28 +0200 Subject: doc: add suggestions about good practises for maintainers Suggest how to deal with patch modifications caused by merging or back-porting when you're a maintainer. Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds --- Documentation/SubmittingPatches | 46 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'Documentation') diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches index 9c93a03..118ca6e 100644 --- a/Documentation/SubmittingPatches +++ b/Documentation/SubmittingPatches @@ -327,6 +327,52 @@ 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. +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 + [lucky@maintainer.example.org: struct foo moved from foo.c to foo.h] + Signed-off-by: Lucky K Maintainer + +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: -- cgit v1.1 From 6a7d68e899b7f609708e7590784344f03640f774 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Thu, 5 Jun 2008 22:45:54 -0700 Subject: cpusets: fix and update Documentation Make the doc consistent with current cpusets implementation. Signed-off-by: Miao Xie Acked-by: Paul Jackson Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/cpusets.txt | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index fb7b361..d803c5c 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -199,7 +199,7 @@ using the sched_setaffinity, mbind and set_mempolicy system calls. The following rules apply to each cpuset: - Its CPUs and Memory Nodes must be a subset of its parents. - - It can only be marked exclusive if its parent is. + - It can't be marked exclusive unless its parent is. - If its cpu or memory is exclusive, they may not overlap any sibling. These rules, and the natural hierarchy of cpusets, enable efficient @@ -345,7 +345,7 @@ is modified to perform an inline check for this PF_SPREAD_PAGE task flag, and if set, a call to a new routine cpuset_mem_spread_node() returns the node to prefer for the allocation. -Similarly, setting 'memory_spread_cache' turns on the flag +Similarly, setting 'memory_spread_slab' turns on the flag PF_SPREAD_SLAB, and appropriately marked slab caches will allocate pages from the node returned by cpuset_mem_spread_node(). @@ -709,7 +709,10 @@ Now you want to do something with this cpuset. In this directory you can find several files: # ls -cpus cpu_exclusive mems mem_exclusive mem_hardwall tasks +cpu_exclusive memory_migrate mems tasks +cpus memory_pressure notify_on_release +mem_exclusive memory_spread_page sched_load_balance +mem_hardwall memory_spread_slab sched_relax_domain_level Reading them will give you information about the state of this cpuset: the CPUs and Memory Nodes it can use, the processes that are using -- cgit v1.1 From 34397892a3d677d857fdaf8dec66a66b07dde0b5 Mon Sep 17 00:00:00 2001 From: Paul Jackson Date: Thu, 5 Jun 2008 22:46:09 -0700 Subject: doc: update to URL and status of kernel-docs.txt entry Update status and URL for the "Gary's Encyclopedia" entry. Signed-off-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-docs.txt | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kernel-docs.txt b/Documentation/kernel-docs.txt index 5a4ef48..28cdc2a 100644 --- a/Documentation/kernel-docs.txt +++ b/Documentation/kernel-docs.txt @@ -715,14 +715,14 @@ * Name: "Gary's Encyclopedia - The Linux Kernel" Author: Gary (I suppose...). - URL: http://www.lisoleg.net/cgi-bin/lisoleg.pl?view=kernel.htm - Keywords: links, not found here?. + URL: http://slencyclopedia.berlios.de/index.html + Keywords: linux, community, everything! Description: Gary's Encyclopedia exists to allow the rapid finding of documentation and other information of interest to GNU/Linux users. It has about 4000 links to external pages in 150 major categories. This link is for kernel-specific links, documents, - sites... Look there if you could not find here what you were - looking for. + sites... This list is now hosted by developer.Berlios.de, + but seems not to have been updated since sometime in 1999. * Name: "The home page of Linux-MM" Author: The Linux-MM team. -- cgit v1.1 From 44d1b980c72db0faf35adb082fb2208351803028 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 5 Jun 2008 22:46:18 -0700 Subject: Fix various old email addresses for dwmw2 Although if people have questions about ARCnet, perhaps it's _better_ for them to be mailing dwmw2@cam.ac.uk about it... Signed-off-by: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/networking/arcnet.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/networking/arcnet.txt b/Documentation/networking/arcnet.txt index 770fc41..7960125 100644 --- a/Documentation/networking/arcnet.txt +++ b/Documentation/networking/arcnet.txt @@ -46,7 +46,7 @@ These are the ARCnet drivers for Linux. This new release (2.91) has been put together by David Woodhouse -, in an attempt to tidy up the driver after adding support +, in an attempt to tidy up the driver after adding support for yet another chipset. Now the generic support has been separated from the individual chipset drivers, and the source files aren't quite so packed with #ifdefs! I've changed this file a bit, but kept it in the first person from -- cgit v1.1 From 0842b245a8e6c14e3aa49f91018902591d1069b3 Mon Sep 17 00:00:00 2001 From: Paul Jackson Date: Thu, 5 Jun 2008 22:46:45 -0700 Subject: doc: document the kernel-doc conventions for kernel hackers Provide documentation of the kernel-doc documentation conventions oriented to kernel hackers. Since I figure that there will be more people reading this kernel-doc-nano-HOWTO.txt file who are kernel developers focused on the rest of the kernel, than there will be readers of this file who are documentation developers extracting that embedded kernel-doc documentation, I have taken the liberty of making the new section added here: How to format kernel-doc comments the first section of the kernel-doc-nano-HOWTO.txt file. This first section is intended to introduce, motivate and provide basic usage of the kernel-doc mechanism for kernel hackers developing other portions of the kernel. Signed-off-by: Paul Jackson Acked-by: Randy Dunlap Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-doc-nano-HOWTO.txt | 99 +++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-doc-nano-HOWTO.txt b/Documentation/kernel-doc-nano-HOWTO.txt index 2075c06..0bd3274 100644 --- a/Documentation/kernel-doc-nano-HOWTO.txt +++ b/Documentation/kernel-doc-nano-HOWTO.txt @@ -1,6 +1,105 @@ kernel-doc nano-HOWTO ===================== +How to format kernel-doc comments +--------------------------------- + +In order to provide embedded, 'C' friendly, easy to maintain, +but consistent and extractable documentation of the functions and +data structures in the Linux kernel, the Linux kernel has adopted +a consistent style for documenting functions and their parameters, +and structures and their members. + +The format for this documentation is called the kernel-doc format. +It is documented in this Documentation/kernel-doc-nano-HOWTO.txt file. + +This style embeds the documentation within the source files, using +a few simple conventions. The scripts/kernel-doc perl script, some +SGML templates in Documentation/DocBook, and other tools understand +these conventions, and are used to extract this embedded documentation +into various documents. + +In order to provide good documentation of kernel functions and data +structures, please use the following conventions to format your +kernel-doc comments in Linux kernel source. + +We definitely need kernel-doc formatted documentation for functions +that are exported to loadable modules using EXPORT_SYMBOL. + +We also look to provide kernel-doc formatted documentation for +functions externally visible to other kernel files (not marked +"static"). + +We also recommend providing kernel-doc formatted documentation +for private (file "static") routines, for consistency of kernel +source code layout. But this is lower priority and at the +discretion of the MAINTAINER of that kernel source file. + +Data structures visible in kernel include files should also be +documented using kernel-doc formatted comments. + +The opening comment mark "/**" is reserved for kernel-doc comments. +Only comments so marked will be considered by the kernel-doc scripts, +and any comment so marked must be in kernel-doc format. Do not use +"/**" to be begin a comment block unless the comment block contains +kernel-doc formatted comments. The closing comment marker for +kernel-doc comments can be either "*/" or "**/". + +Kernel-doc comments should be placed just before the function +or data structure being described. + +Example kernel-doc function comment: + +/** + * foobar() - short function description of foobar + * @arg1: Describe the first argument to foobar. + * @arg2: Describe the second argument to foobar. + * One can provide multiple line descriptions + * for arguments. + * + * A longer description, with more discussion of the function foobar() + * that might be useful to those using or modifying it. Begins with + * empty comment line, and may include additional embedded empty + * comment lines. + * + * The longer description can have multiple paragraphs. + **/ + +The first line, with the short description, must be on a single line. + +The @argument descriptions must begin on the very next line following +this opening short function description line, with no intervening +empty comment lines. + +Example kernel-doc data structure comment. + +/** + * struct blah - the basic blah structure + * @mem1: describe the first member of struct blah + * @mem2: describe the second member of struct blah, + * perhaps with more lines and words. + * + * Longer description of this structure. + **/ + +The kernel-doc function comments describe each parameter to the +function, in order, with the @name lines. + +The kernel-doc data structure comments describe each structure member +in the data structure, with the @name lines. + +The longer description formatting is "reflowed", losing your line +breaks. So presenting carefully formatted lists within these +descriptions won't work so well; derived documentation will lose +the formatting. + +See the section below "How to add extractable documentation to your +source files" for more details and notes on how to format kernel-doc +comments. + +Components of the kernel-doc system +----------------------------------- + Many places in the source tree have extractable documentation in the form of block comments above functions. The components of this system are: -- cgit v1.1 From ef421be741a3e56cb89088a7dd4f73cc38739d1b Mon Sep 17 00:00:00 2001 From: Thomas Tuttle Date: Thu, 5 Jun 2008 22:46:59 -0700 Subject: pagemap: add documentation for pagemap Just a quick explanation of the pagemap interface from a userspace point of view, and an example of how to use it (in English, not code). Signed-off-by: Thomas Tuttle Cc: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/vm/pagemap.txt | 77 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 Documentation/vm/pagemap.txt (limited to 'Documentation') diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt new file mode 100644 index 0000000..ce72c0f --- /dev/null +++ b/Documentation/vm/pagemap.txt @@ -0,0 +1,77 @@ +pagemap, from the userspace perspective +--------------------------------------- + +pagemap is a new (as of 2.6.25) set of interfaces in the kernel that allow +userspace programs to examine the page tables and related information by +reading files in /proc. + +There are three components to pagemap: + + * /proc/pid/pagemap. This file lets a userspace process find out which + physical frame each virtual page is mapped to. It contains one 64-bit + value for each virtual page, containing the following data (from + fs/proc/task_mmu.c, above pagemap_read): + + * Bits 0-55 page frame number (PFN) if present + * Bits 0-4 swap type if swapped + * Bits 5-55 swap offset if swapped + * Bits 55-60 page shift (page size = 1<