From 096abd77038a2ff74efd194d074eadcde80fb97d Mon Sep 17 00:00:00 2001 From: James Lentini Date: Thu, 8 Jan 2009 13:13:26 -0500 Subject: update port number in NFS/RDMA documentation Update the NFS/RDMA documentation to use the new port number assigned by IANA. Signed-off-by: James Lentini Signed-off-by: J. Bruce Fields --- Documentation/filesystems/nfs-rdma.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/filesystems/nfs-rdma.txt b/Documentation/filesystems/nfs-rdma.txt index 44bd766f2e5d..85eaeaddd27c 100644 --- a/Documentation/filesystems/nfs-rdma.txt +++ b/Documentation/filesystems/nfs-rdma.txt @@ -251,7 +251,7 @@ NFS/RDMA Setup Instruct the server to listen on the RDMA transport: - $ echo rdma 2050 > /proc/fs/nfsd/portlist + $ echo rdma 20049 > /proc/fs/nfsd/portlist - On the client system @@ -263,7 +263,7 @@ NFS/RDMA Setup Regardless of how the client was built (module or built-in), use this command to mount the NFS/RDMA server: - $ mount -o rdma,port=2050 :/ /mnt + $ mount -o rdma,port=20049 :/ /mnt To verify that the mount is using RDMA, run "cat /proc/mounts" and check the "proto" field for the given mount. -- cgit v1.2.2 From 720893fd5fb6de1f752f816a89e630f08ae8b20a Mon Sep 17 00:00:00 2001 From: Tsugikazu Shibata Date: Fri, 23 Jan 2009 09:59:50 +0900 Subject: Sync patch for jp_JP/stable_kernel_rules.txt Updated jp_JP/stable_kernel_rules.txt due to changes in the main version of the file. Also, this patch is already reviewed by Japanese translation community called JF. Signed-off-by: Tsugikazu Shibata Signed-off-by: Greg Kroah-Hartman --- Documentation/ja_JP/stable_kernel_rules.txt | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ja_JP/stable_kernel_rules.txt b/Documentation/ja_JP/stable_kernel_rules.txt index b3ffe870de33..14265837c4ce 100644 --- a/Documentation/ja_JP/stable_kernel_rules.txt +++ b/Documentation/ja_JP/stable_kernel_rules.txt @@ -12,11 +12,11 @@ file at first. ================================== これは、 -linux-2.6.24/Documentation/stable_kernel_rules.txt +linux-2.6.29/Documentation/stable_kernel_rules.txt の和訳です。 翻訳団体： JF プロジェクト < http://www.linux.or.jp/JF/ > -翻訳日： 2007/12/30 +翻訳日： 2009/1/14 翻訳者： Tsugikazu Shibata 校正者： 武井伸光さん、 かねこさん (Seiji Kaneko) @@ -38,12 +38,15 @@ linux-2.6.24/Documentation/stable_kernel_rules.txt - ビルドエラー(CONFIG_BROKENになっているものを除く), oops, ハング、デー タ破壊、現実のセキュリティ問題、その他 "ああ、これはダメだね"という ようなものを修正しなければならない。短く言えば、重大な問題。 + - 新しい device ID とクオークも受け入れられる。 - どのように競合状態が発生するかの説明も一緒に書かれていない限り、 "理論的には競合状態になる"ようなものは不可。 - いかなる些細な修正も含めることはできない。(スペルの修正、空白のクリー ンアップなど) - - 対応するサブシステムメンテナが受け入れたものでなければならない。 - Documentation/SubmittingPatches の規則に従ったものでなければならない。 + - パッチ自体か同等の修正が Linus のツリーに既に存在しなければならない。 +　 Linus のツリーでのコミットID を -stable へのパッチ投稿の際に引用す + ること。 -stable ツリーにパッチを送付する手続き- @@ -52,8 +55,10 @@ linux-2.6.24/Documentation/stable_kernel_rules.txt - 送信者はパッチがキューに受け付けられた際には ACK を、却下された場合 には NAK を受け取る。この反応は開発者たちのスケジュールによって、数 日かかる場合がある。 - - もし受け取られたら、パッチは他の開発者たちのレビューのために - -stable キューに追加される。 + - もし受け取られたら、パッチは他の開発者たちと関連するサブシステムの + メンテナーによるレビューのために -stable キューに追加される。 + - パッチに stable@kernel.org のアドレスが付加されているときには、それ + が Linus のツリーに入る時に自動的に stable チームに email される。 - セキュリティパッチはこのエイリアス (stable@kernel.org) に送られるべ きではなく、代わりに security@kernel.org のアドレスに送られる。 -- cgit v1.2.2 From 6a1b699678c8c0d45f88a37b32358a9e82bef6bb Mon Sep 17 00:00:00 2001 From: "Hans J. Koch" Date: Wed, 7 Jan 2009 00:12:37 +0100 Subject: UIO: Add missing documentation of features added recently MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The following features were added to the UIO framework in the near past: * Generic drivers for platform devices (uio_pdrv, uio_pdrv_genirq) * an "offset" sysfs attribute for memory mappings Unfortunately, all this went in without documentation (won't happen again...) This patch updates UIO documentation. Signed-off-by: Hans J. Koch Acked-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- Documentation/DocBook/uio-howto.tmpl | 88 ++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) (limited to 'Documentation') diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl index b787e4721c90..52e1b79ce0e6 100644 --- a/Documentation/DocBook/uio-howto.tmpl +++ b/Documentation/DocBook/uio-howto.tmpl @@ -41,6 +41,12 @@ GPL version 2. + + 0.7 + 2008-12-23 + hjk + Added generic platform drivers and offset attribute. + 0.6 2008-12-05 @@ -312,6 +318,16 @@ interested in translating it, please email me pointed to by addr. + + + offset: The offset, in bytes, that has to be + added to the pointer returned by mmap() to get + to the actual device memory. This is important if the device's memory + is not page aligned. Remember that pointers returned by + mmap() are always page aligned, so it is good + style to always add this offset. + + @@ -594,6 +610,78 @@ framework to set up sysfs files for this region. Simply leave it alone. + +Using uio_pdrv for platform devices + + In many cases, UIO drivers for platform devices can be handled in a + generic way. In the same place where you define your + struct platform_device, you simply also implement + your interrupt handler and fill your + struct uio_info. A pointer to this + struct uio_info is then used as + platform_data for your platform device. + + + You also need to set up an array of struct resource + containing addresses and sizes of your memory mappings. This + information is passed to the driver using the + .resource and .num_resources + elements of struct platform_device. + + + You now have to set the .name element of + struct platform_device to + "uio_pdrv" to use the generic UIO platform device + driver. This driver will fill the mem[] array + according to the resources given, and register the device. + + + The advantage of this approach is that you only have to edit a file + you need to edit anyway. You do not have to create an extra driver. + + + + +Using uio_pdrv_genirq for platform devices + + Especially in embedded devices, you frequently find chips where the + irq pin is tied to its own dedicated interrupt line. In such cases, + where you can be really sure the interrupt is not shared, we can take + the concept of uio_pdrv one step further and use a + generic interrupt handler. That's what + uio_pdrv_genirq does. + + + The setup for this driver is the same as described above for + uio_pdrv, except that you do not implement an + interrupt handler. The .handler element of + struct uio_info must remain + NULL. The .irq_flags element + must not contain IRQF_SHARED. + + + You will set the .name element of + struct platform_device to + "uio_pdrv_genirq" to use this driver. + + + The generic interrupt handler of uio_pdrv_genirq + will simply disable the interrupt line using + disable_irq_nosync(). After doing its work, + userspace can reenable the interrupt by writing 0x00000001 to the UIO + device file. The driver already implements an + irq_control() to make this possible, you must not + implement your own. + + + Using uio_pdrv_genirq not only saves a few lines of + interrupt handler code. You also do not need to know anything about + the chip's internal registers to create the kernel part of the driver. + All you need to know is the irq number of the pin the chip is + connected to. + + + -- cgit v1.2.2 From f90c3c0bdd7a3f16eecf1b077f5e031c44ddb605 Mon Sep 17 00:00:00 2001 From: Simon Harrison Date: Fri, 9 Jan 2009 09:07:07 -0300 Subject: V4L/DVB (10210): Fix a bug on v4lgrab.c v4lgrab breaks the fputc macro on some systems, because of #defined FILE. Also, I also added comments because it was not at all clear that to get gspca cameras to work with this application you need v4l1compat. Signed-off-by: Simon Harrison Signed-off-by: Mauro Carvalho Chehab --- Documentation/video4linux/v4lgrab.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'Documentation') diff --git a/Documentation/video4linux/v4lgrab.c b/Documentation/video4linux/v4lgrab.c index 079b628481cf..d6e70bef8ad0 100644 --- a/Documentation/video4linux/v4lgrab.c +++ b/Documentation/video4linux/v4lgrab.c @@ -4,12 +4,21 @@ * * Compile with: * gcc -s -Wall -Wstrict-prototypes v4lgrab.c -o v4lgrab - * Use as: - * v4lgrab >image.ppm + * Use as: + * v4lgrab >image.ppm * * Copyright (C) 1998-05-03, Phil Blundell - * Copied from http://www.tazenda.demon.co.uk/phil/vgrabber.c - * with minor modifications (Dave Forrest, drf5n@virginia.edu). + * Copied from http://www.tazenda.demon.co.uk/phil/vgrabber.c + * with minor modifications (Dave Forrest, drf5n@virginia.edu). + * + * + * For some cameras you may need to pre-load libv4l to perform + * the necessary decompression, e.g.: + * + * export LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so + * ./v4lgrab >image.ppm + * + * see http://hansdegoede.livejournal.com/3636.html for details. * */ @@ -24,7 +33,7 @@ #include #include -#define FILE "/dev/video0" +#define VIDEO_DEV "/dev/video0" /* Stole this from tvset.c */ @@ -90,7 +99,7 @@ int get_brightness_adj(unsigned char *image, long size, int *brightness) { int main(int argc, char ** argv) { - int fd = open(FILE, O_RDONLY), f; + int fd = open(VIDEO_DEV, O_RDONLY), f; struct video_capability cap; struct video_window win; struct video_picture vpic; @@ -100,13 +109,13 @@ int main(int argc, char ** argv) unsigned int i, src_depth; if (fd < 0) { - perror(FILE); + perror(VIDEO_DEV); exit(1); } if (ioctl(fd, VIDIOCGCAP, &cap) < 0) { perror("VIDIOGCAP"); - fprintf(stderr, "(" FILE " not a video4linux device?)\n"); + fprintf(stderr, "(" VIDEO_DEV " not a video4linux device?)\n"); close(fd); exit(1); } -- cgit v1.2.2 From b44d49ab0954accefba4c71274ab58abe1c25c52 Mon Sep 17 00:00:00 2001 From: Tim 'mithro' Ansell Date: Thu, 22 Jan 2009 15:06:41 +1100 Subject: lguest: disable the FORTIFY for lguest. Makes all the warnings go away when compiling lguest on Ubuntu on Intrepid or greater. Signed-off-by: Timothy R Ansell Signed-off-by: Rusty Russell --- Documentation/lguest/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/lguest/Makefile b/Documentation/lguest/Makefile index 725eef81cd48..1f4f9e888bd1 100644 --- a/Documentation/lguest/Makefile +++ b/Documentation/lguest/Makefile @@ -1,5 +1,5 @@ # This creates the demonstration utility "lguest" which runs a Linux guest. -CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -I../../include -I../../arch/x86/include +CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -I../../include -I../../arch/x86/include -U_FORTIFY_SOURCE LDLIBS:=-lz all: lguest -- cgit v1.2.2 From 9e9e3cbc62da43c66e894d5a61fa08b427e25202 Mon Sep 17 00:00:00 2001 From: Evgeniy Polyakov Date: Thu, 29 Jan 2009 14:25:09 -0800 Subject: mm: OOM documentation update Signed-off-by: Evgeniy Polyakov Acked-by: David Rientjes Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/filesystems/proc.txt | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'Documentation') diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index bbebc3a43ac0..a87be42f8211 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -2027,6 +2027,34 @@ increase the likelihood of this process being killed by the oom-killer. Valid values are in the range -16 to +15, plus the special value -17, which disables oom-killing altogether for this process. +The process to be killed in an out-of-memory situation is selected among all others +based on its badness score. This value equals the original memory size of the process +and is then updated according to its CPU time (utime + stime) and the +run time (uptime - start time). The longer it runs the smaller is the score. +Badness score is divided by the square root of the CPU time and then by +the double square root of the run time. + +Swapped out tasks are killed first. Half of each child's memory size is added to +the parent's score if they do not share the same memory. Thus forking servers +are the prime candidates to be killed. Having only one 'hungry' child will make +parent less preferable than the child. + +/proc//oom_score shows process' current badness score. + +The following heuristics are then applied: + * if the task was reniced, its score doubles + * superuser or direct hardware access tasks (CAP_SYS_ADMIN, CAP_SYS_RESOURCE + or CAP_SYS_RAWIO) have their score divided by 4 + * if oom condition happened in one cpuset and checked task does not belong + to it, its score is divided by 8 + * the resulting score is multiplied by two to the power of oom_adj, i.e. + points <<= oom_adj when it is positive and + points >>= -(oom_adj) otherwise + +The task with the highest badness score is then selected and its children +are killed, process itself will be killed in an OOM situation when it does +not have children or some of them disabled oom like described above. + 2.13 /proc//oom_score - Display current oom-killer score ------------------------------------------------------------- -- cgit v1.2.2 From 8d50d369d1b3ccc4d96ce01f62146173ee7064ca Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Thu, 29 Jan 2009 14:25:14 -0800 Subject: memcg: update document to mention that swapoff should be tested Considering the recently found problem "memcg: fix refcnt handling at swapoff", it's better to mention swapoff behavior in the memcg_test document. Signed-off-by: KAMEZAWA Hiroyuki Acked-by: Balbir Singh Cc: Li Zefan Cc: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/cgroups/memcg_test.txt | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt index 19533f93b7a2..523a9c16c400 100644 --- a/Documentation/cgroups/memcg_test.txt +++ b/Documentation/cgroups/memcg_test.txt @@ -1,6 +1,6 @@ Memory Resource Controller(Memcg) Implementation Memo. -Last Updated: 2008/12/15 -Base Kernel Version: based on 2.6.28-rc8-mm. +Last Updated: 2009/1/19 +Base Kernel Version: based on 2.6.29-rc2. Because VM is getting complex (one of reasons is memcg...), memcg's behavior is complex. This is a document for memcg's internal behavior. @@ -340,3 +340,23 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. # mount -t cgroup none /cgroup -t cpuset,memory,cpu,devices and do task move, mkdir, rmdir etc...under this. + + 9.7 swapoff. + Besides management of swap is one of complicated parts of memcg, + call path of swap-in at swapoff is not same as usual swap-in path.. + It's worth to be tested explicitly. + + For example, test like following is good. + (Shell-A) + # mount -t cgroup none /cgroup -t memory + # mkdir /cgroup/test + # echo 40M > /cgroup/test/memory.limit_in_bytes + # echo 0 > /cgroup/test/tasks + Run malloc(100M) program under this. You'll see 60M of swaps. + (Shell-B) + # move all tasks in /cgroup/test to /cgroup + # /sbin/swapoff -a + # rmdir /test/cgroup + # kill malloc task. + + Of course, tmpfs v.s. swapoff test should be tested, too. -- cgit v1.2.2 From 5872fb94f85d2e4fdef94657bd14e1a492df9825 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Thu, 29 Jan 2009 16:28:02 -0800 Subject: Documentation: move DMA-mapping.txt to Doc/PCI/ Move DMA-mapping.txt to Documentation/PCI/. DMA-mapping.txt was supposed to be moved from Documentation/ to Documentation/PCI/. The 00-INDEX files in those two directories were updated, along with a few other text files, but the file itself somehow escaped being moved, so move it and update more text files and source files with its new location. Signed-off-by: Randy Dunlap Acked-by: Greg Kroah-Hartman cc: Jesse Barnes Signed-off-by: Linus Torvalds --- Documentation/DMA-API.txt | 2 +- Documentation/IO-mapping.txt | 4 ++-- Documentation/block/biodoc.txt | 5 +++-- Documentation/usb/dma.txt | 11 ++++++----- 4 files changed, 12 insertions(+), 10 deletions(-) (limited to 'Documentation') diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 52441694fe03..2a3fcc55e981 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -5,7 +5,7 @@ This document describes the DMA API. For a more gentle introduction phrased in terms of the pci_ equivalents (and actual examples) see -DMA-mapping.txt +Documentation/PCI/PCI-DMA-mapping.txt. This API is split into two pieces. Part I describes the API and the corresponding pci_ API. Part II describes the extensions to the API diff --git a/Documentation/IO-mapping.txt b/Documentation/IO-mapping.txt index 86edb61bdee6..78a440695e11 100644 --- a/Documentation/IO-mapping.txt +++ b/Documentation/IO-mapping.txt @@ -1,6 +1,6 @@ [ NOTE: The virt_to_bus() and bus_to_virt() functions have been - superseded by the functionality provided by the PCI DMA - interface (see Documentation/DMA-mapping.txt). They continue + superseded by the functionality provided by the PCI DMA interface + (see Documentation/PCI/PCI-DMA-mapping.txt). They continue to be documented below for historical purposes, but new code must not use them. --davidm 00/12/12 ] diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 3c5434c83daf..5d2480d33b43 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -186,8 +186,9 @@ a virtual address mapping (unlike the earlier scheme of virtual address do not have a corresponding kernel virtual address space mapping) and low-memory pages. -Note: Please refer to DMA-mapping.txt for a discussion on PCI high mem DMA -aspects and mapping of scatter gather lists, and support for 64 bit PCI. +Note: Please refer to Documentation/PCI/PCI-DMA-mapping.txt for a discussion +on PCI high mem DMA aspects and mapping of scatter gather lists, and support +for 64 bit PCI. Special handling is required only for cases where i/o needs to happen on pages at physical memory addresses beyond what the device can support. In these diff --git a/Documentation/usb/dma.txt b/Documentation/usb/dma.txt index e8b50b7de9d9..cfdcd16e3abf 100644 --- a/Documentation/usb/dma.txt +++ b/Documentation/usb/dma.txt @@ -6,8 +6,9 @@ in the kernel usb programming guide (kerneldoc, from the source code). API OVERVIEW The big picture is that USB drivers can continue to ignore most DMA issues, -though they still must provide DMA-ready buffers (see DMA-mapping.txt). -That's how they've worked through the 2.4 (and earlier) kernels. +though they still must provide DMA-ready buffers (see +Documentation/PCI/PCI-DMA-mapping.txt). That's how they've worked through +the 2.4 (and earlier) kernels. OR: they can now be DMA-aware. @@ -62,8 +63,8 @@ and effects like cache-trashing can impose subtle penalties. force a consistent memory access ordering by using memory barriers. It's not using a streaming DMA mapping, so it's good for small transfers on systems where the I/O would otherwise thrash an IOMMU mapping. (See - Documentation/DMA-mapping.txt for definitions of "coherent" and "streaming" - DMA mappings.) + Documentation/PCI/PCI-DMA-mapping.txt for definitions of "coherent" and + "streaming" DMA mappings.) Asking for 1/Nth of a page (as well as asking for N pages) is reasonably space-efficient. @@ -93,7 +94,7 @@ WORKING WITH EXISTING BUFFERS Existing buffers aren't usable for DMA without first being mapped into the DMA address space of the device. However, most buffers passed to your driver can safely be used with such DMA mapping. (See the first section -of DMA-mapping.txt, titled "What memory is DMA-able?") +of Documentation/PCI/PCI-DMA-mapping.txt, titled "What memory is DMA-able?") - When you're using scatterlists, you can map everything at once. On some systems, this kicks in an IOMMU and turns the scatterlists into single -- cgit v1.2.2 From 0acbc6c651911dc9ffb4f59b34306bc1ccb751e5 Mon Sep 17 00:00:00 2001 From: Teemu Likonen Date: Thu, 29 Jan 2009 16:28:16 -0800 Subject: Documentation: update CodingStyle tips for Emacs users With the previous Emacs tips example the kernel style was made available for files in the kernel-tree only. This patch updates the tip to add a separate cc-mode indent style ("linux-tabs-only"). This makes it easy to switch between different indent styles and also makes the kernel style easily available for any filetype mode (c++, awk, ...) that is managed by the Emacs cc-mode. Signed-off-by: Teemu Likonen Signed-off-by: Randy Dunlap Signed-off-by: Linus Torvalds --- Documentation/CodingStyle | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index 1875e502f872..7b5762eded2c 100644 --- a/Documentation/CodingStyle +++ b/Documentation/CodingStyle @@ -483,6 +483,16 @@ values. To do the latter, you can stick the following in your .emacs file: (* (max steps 1) c-basic-offset))) +(add-hook 'c-mode-common-hook + (lambda () + ;; Add kernel style + (c-add-style + "linux-tabs-only" + '("linux" (c-offsets-alist + (arglist-cont-nonempty + c-lineup-gcc-asm-reg + c-lineup-arglist-tabs-only)))))) + (add-hook 'c-mode-hook (lambda () (let ((filename (buffer-file-name))) @@ -490,10 +500,7 @@ values. To do the latter, you can stick the following in your .emacs file: (when (and filename (string-match "~/src/linux-trees" filename)) (setq indent-tabs-mode t) - (c-set-style "linux") - (c-set-offset 'arglist-cont-nonempty - '(c-lineup-gcc-asm-reg - c-lineup-arglist-tabs-only)))))) + (c-set-style "linux-tabs-only"))))) This will make emacs go better with the kernel coding style for C files below ~/src/linux-trees. -- cgit v1.2.2 From 70221395ba980392ba98c1d78f6c9f77be03df9e Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 29 Jan 2009 16:28:28 -0800 Subject: fix emacs indenting howto filename expansion I don't think emacs understands tilde expansion, so use "expand-file-name" to do that. Signed-off-by: Dan Carpenter Signed-off-by: Randy Dunlap Signed-off-by: Linus Torvalds --- Documentation/CodingStyle | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index 7b5762eded2c..72968cd5eaf3 100644 --- a/Documentation/CodingStyle +++ b/Documentation/CodingStyle @@ -498,7 +498,8 @@ values. To do the latter, you can stick the following in your .emacs file: (let ((filename (buffer-file-name))) ;; Enable kernel mode for the appropriate files (when (and filename - (string-match "~/src/linux-trees" filename)) + (string-match (expand-file-name "~/src/linux-trees") + filename)) (setq indent-tabs-mode t) (c-set-style "linux-tabs-only"))))) -- cgit v1.2.2 From 242f45da5b7bf63c50f1f18301750712e7885dd6 Mon Sep 17 00:00:00 2001 From: Bill Nottingham Date: Thu, 29 Jan 2009 16:28:40 -0800 Subject: Documentation/Changes: add required versions for new filesystems btrfs requires version 0.18 of its tools, and squashfs requires 4.0. ext3 should use and ext4 requires v1.41.4 of e2fsprogs. Signed-off-by: Bill Nottingham Signed-off-by: Randy Dunlap cc: Ted Tso Signed-off-by: Linus Torvalds --- Documentation/Changes | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/Changes b/Documentation/Changes index cb2b141b1c3e..b95082be4d5e 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -33,10 +33,12 @@ o Gnu make 3.79.1 # make --version o binutils 2.12 # ld -v o util-linux 2.10o # fdformat --version o module-init-tools 0.9.10 # depmod -V -o e2fsprogs 1.29 # tune2fs +o e2fsprogs 1.41.4 # e2fsck -V o jfsutils 1.1.3 # fsck.jfs -V o reiserfsprogs 3.6.3 # reiserfsck -V 2>&1|grep reiserfsprogs o xfsprogs 2.6.0 # xfs_db -V +o squashfs-tools 4.0 # mksquashfs -version +o btrfs-progs 0.18 # btrfsck o pcmciautils 004 # pccardctl -V o quota-tools 3.09 # quota -V o PPP 2.4.0 # pppd --version -- cgit v1.2.2 From 7598909e3ee2a08726276d6415b69dadb52d0d76 Mon Sep 17 00:00:00 2001 From: Nikanth Karthikesan Date: Tue, 27 Jan 2009 09:29:24 +0100 Subject: Mark mandatory elevator functions in the biodoc.txt biodoc.txt mentions that elevator functions marked with * are mandatory, but no function is marked with *. Mark the 3 functions which should be implemented by any io scheduler. Signed-off-by: Nikanth Karthikesan Signed-off-by: Jens Axboe --- Documentation/block/biodoc.txt | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 5d2480d33b43..ecad6ee75705 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -954,14 +954,14 @@ elevator_allow_merge_fn called whenever the block layer determines results in some sort of conflict internally, this hook allows it to do that. -elevator_dispatch_fn fills the dispatch queue with ready requests. +elevator_dispatch_fn* fills the dispatch queue with ready requests. I/O schedulers are free to postpone requests by not filling the dispatch queue unless @force is non-zero. Once dispatched, I/O schedulers are not allowed to manipulate the requests - they belong to generic dispatch queue. -elevator_add_req_fn called to add a new request into the scheduler +elevator_add_req_fn* called to add a new request into the scheduler elevator_queue_empty_fn returns true if the merge queue is empty. Drivers shouldn't use this, but rather check @@ -991,7 +991,7 @@ elevator_activate_req_fn Called when device driver first sees a request. elevator_deactivate_req_fn Called when device driver decides to delay a request by requeueing it. -elevator_init_fn +elevator_init_fn* elevator_exit_fn Allocate and free any elevator specific storage for a queue. -- cgit v1.2.2 From 34df9f69a4e298e2e8b939d8a7cc0d55846ba544 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 30 Jan 2009 08:23:33 -0700 Subject: powerpc/5200: update device tree binding documentation This patch updates the mpc5200 binding documentation to match actual usage conventions, to remove incorrect information, and to remove topics which are more thoroughly described elsewhere. Signed-off-by: Grant Likely Reviewed-by: Wolfram Sang --- Documentation/powerpc/dts-bindings/fsl/mpc5200.txt | 180 +++++++++++++ .../powerpc/mpc52xx-device-tree-bindings.txt | 277 --------------------- 2 files changed, 180 insertions(+), 277 deletions(-) create mode 100644 Documentation/powerpc/dts-bindings/fsl/mpc5200.txt delete mode 100644 Documentation/powerpc/mpc52xx-device-tree-bindings.txt (limited to 'Documentation') diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt new file mode 100644 index 000000000000..8447fd7090d0 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt @@ -0,0 +1,180 @@ +MPC5200 Device Tree Bindings +---------------------------- + +(c) 2006-2009 Secret Lab Technologies Ltd +Grant Likely + +Naming conventions +------------------ +For mpc5200 on-chip devices, the format for each compatible value is +-[-]. The OS should be able to match a device driver +to the device based solely on the compatible value. If two drivers +match on the compatible list; the 'most compatible' driver should be +selected. + +The split between the MPC5200 and the MPC5200B leaves a bit of a +conundrum. How should the compatible property be set up to provide +maximum compatibility information; but still accurately describe the +chip? For the MPC5200; the answer is easy. Most of the SoC devices +originally appeared on the MPC5200. Since they didn't exist anywhere +else; the 5200 compatible properties will contain only one item; +"fsl,mpc5200-". + +The 5200B is almost the same as the 5200, but not quite. It fixes +silicon bugs and it adds a small number of enhancements. Most of the +devices either provide exactly the same interface as on the 5200. A few +devices have extra functions but still have a backwards compatible mode. +To express this information as completely as possible, 5200B device trees +should have two items in the compatible list: + compatible = "fsl,mpc5200b-","fsl,mpc5200-"; + +It is *strongly* recommended that 5200B device trees follow this convention +(instead of only listing the base mpc5200 item). + +ie. ethernet on mpc5200: compatible = "fsl,mpc5200-fec"; + ethernet on mpc5200b: compatible = "fsl,mpc5200b-fec", "fsl,mpc5200-fec"; + +Modal devices, like PSCs, also append the configured function to the +end of the compatible field. ie. A PSC in i2s mode would specify +"fsl,mpc5200-psc-i2s", not "fsl,mpc5200-i2s". This convention is chosen to +avoid naming conflicts with non-psc devices providing the same +function. For example, "fsl,mpc5200-spi" and "fsl,mpc5200-psc-spi" describe +the mpc5200 simple spi device and a PSC spi mode respectively. + +At the time of writing, exact chip may be either 'fsl,mpc5200' or +'fsl,mpc5200b'. + +The soc node +------------ +This node describes the on chip SOC peripherals. Every mpc5200 based +board will have this node, and as such there is a common naming +convention for SOC devices. + +Required properties: +name description +---- ----------- +ranges Memory range of the internal memory mapped registers. + Should be <0 [baseaddr] 0xc000> +reg Should be <[baseaddr] 0x100> +compatible mpc5200: "fsl,mpc5200-immr" + mpc5200b: "fsl,mpc5200b-immr" +system-frequency 'fsystem' frequency in Hz; XLB, IPB, USB and PCI + clocks are derived from the fsystem clock. +bus-frequency IPB bus frequency in Hz. Clock rate + used by most of the soc devices. + +soc child nodes +--------------- +Any on chip SOC devices available to Linux must appear as soc5200 child nodes. + +Note: The tables below show the value for the mpc5200. A mpc5200b device +tree should use the "fsl,mpc5200b-","fsl,mpc5200-" form. + +Required soc5200 child nodes: +name compatible Description +---- ---------- ----------- +cdm@ fsl,mpc5200-cdm Clock Distribution +interrupt-controller@ fsl,mpc5200-pic need an interrupt + controller to boot +bestcomm@ fsl,mpc5200-bestcomm Bestcomm DMA controller + +Recommended soc5200 child nodes; populate as needed for your board +name compatible Description +---- ---------- ----------- +timer@ fsl,mpc5200-gpt General purpose timers +gpio@ fsl,mpc5200-gpio MPC5200 simple gpio controller +gpio@ fsl,mpc5200-gpio-wkup MPC5200 wakeup gpio controller +rtc@ fsl,mpc5200-rtc Real time clock +mscan@ fsl,mpc5200-mscan CAN bus controller +pci@ fsl,mpc5200-pci PCI bridge +serial@ fsl,mpc5200-psc-uart PSC in serial mode +i2s@ fsl,mpc5200-psc-i2s PSC in i2s mode +ac97@ fsl,mpc5200-psc-ac97 PSC in ac97 mode +spi@ fsl,mpc5200-psc-spi PSC in spi mode +irda@ fsl,mpc5200-psc-irda PSC in IrDA mode +spi@ fsl,mpc5200-spi MPC5200 spi device +ethernet@ fsl,mpc5200-fec MPC5200 ethernet device +ata@ fsl,mpc5200-ata IDE ATA interface +i2c@ fsl,mpc5200-i2c I2C controller +usb@ fsl,mpc5200-ohci,ohci-be USB controller +xlb@ fsl,mpc5200-xlb XLB arbitrator + +fsl,mpc5200-gpt nodes +--------------------- +On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board +design supports the internal wdt, then the device node for GPT0 should +include the empty property 'fsl,has-wdt'. + +An mpc5200-gpt can be used as a single line GPIO controller. To do so, +add the following properties to the gpt node: + gpio-controller; + #gpio-cells = <2>; +When referencing the GPIO line from another node, the first cell must always +be zero and the second cell represents the gpio flags and described in the +gpio device tree binding. + +An mpc5200-gpt can be used as a single line edge sensitive interrupt +controller. To do so, add the following properties to the gpt node: + interrupt-controller; + #interrupt-cells = <1>; +When referencing the IRQ line from another node, the cell represents the +sense mode; 1 for edge rising, 2 for edge falling. + +fsl,mpc5200-psc nodes +--------------------- +The PSCs should include a cell-index which is the index of the PSC in +hardware. cell-index is used to determine which shared SoC registers to +use when setting up PSC clocking. cell-index number starts at '0'. ie: + PSC1 has 'cell-index = <0>' + PSC4 has 'cell-index = <3>' + +PSC in i2s mode: The mpc5200 and mpc5200b PSCs are not compatible when in +i2s mode. An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the +compatible field. + + +fsl,mpc5200-gpio and fsl,mpc5200-gpio-wkup nodes +------------------------------------------------ +Each GPIO controller node should have the empty property gpio-controller and +#gpio-cells set to 2. First cell is the GPIO number which is interpreted +according to the bit numbers in the GPIO control registers. The second cell +is for flags which is currently unused. + +fsl,mpc5200-fec nodes +--------------------- +The FEC node can specify one of the following properties to configure +the MII link: +- fsl,7-wire-mode - An empty property that specifies the link uses 7-wire + mode instead of MII +- current-speed - Specifies that the MII should be configured for a fixed + speed. This property should contain two cells. The + first cell specifies the speed in Mbps and the second + should be '0' for half duplex and '1' for full duplex +- phy-handle - Contains a phandle to an Ethernet PHY. + +Interrupt controller (fsl,mpc5200-pic) node +------------------------------------------- +The mpc5200 pic binding splits hardware IRQ numbers into two levels. The +split reflects the layout of the PIC hardware itself, which groups +interrupts into one of three groups; CRIT, MAIN or PERP. Also, the +Bestcomm dma engine has it's own set of interrupt sources which are +cascaded off of peripheral interrupt 0, which the driver interprets as a +fourth group, SDMA. + +The interrupts property for device nodes using the mpc5200 pic consists +of three cells; + + L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3] + L2 := interrupt number; directly mapped from the value in the + "ICTL PerStat, MainStat, CritStat Encoded Register" + level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3] + +For external IRQs, use the following interrupt property values (how to +specify external interrupts is a frequently asked question): +External interrupts: + external irq0: interrupts = <0 0 n>; + external irq1: interrupts = <1 1 n>; + external irq2: interrupts = <1 2 n>; + external irq3: interrupts = <1 3 n>; +'n' is sense (0: level high, 1: edge rising, 2: edge falling 3: level low) + diff --git a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt b/Documentation/powerpc/mpc52xx-device-tree-bindings.txt deleted file mode 100644 index 6f12f1c79c0c..000000000000 --- a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt +++ /dev/null @@ -1,277 +0,0 @@ -MPC5200 Device Tree Bindings ----------------------------- - -(c) 2006-2007 Secret Lab Technologies Ltd -Grant Likely - -********** DRAFT *********** -* WARNING: Do not depend on the stability of these bindings just yet. -* The MPC5200 device tree conventions are still in flux -* Keep an eye on the linuxppc-dev mailing list for more details -********** DRAFT *********** - -I - Introduction -================ -Boards supported by the arch/powerpc architecture require device tree be -passed by the boot loader to the kernel at boot time. The device tree -describes what devices are present on the board and how they are -connected. The device tree can either be passed as a binary blob (as -described in Documentation/powerpc/booting-without-of.txt), or passed -by Open Firmware (IEEE 1275) compatible firmware using an OF compatible -client interface API. - -This document specifies the requirements on the device-tree for mpc5200 -based boards. These requirements are above and beyond the details -specified in either the Open Firmware spec or booting-without-of.txt - -All new mpc5200-based boards are expected to match this document. In -cases where this document is not sufficient to support a new board port, -this document should be updated as part of adding the new board support. - -II - Philosophy -=============== -The core of this document is naming convention. The whole point of -defining this convention is to reduce or eliminate the number of -special cases required to support a 5200 board. If all 5200 boards -follow the same convention, then generic 5200 support code will work -rather than coding special cases for each new board. - -This section tries to capture the thought process behind why the naming -convention is what it is. - -1. names ---------- -There is strong convention/requirements already established for children -of the root node. 'cpus' describes the processor cores, 'memory' -describes memory, and 'chosen' provides boot configuration. Other nodes -are added to describe devices attached to the processor local bus. - -Following convention already established with other system-on-chip -processors, 5200 device trees should use the name 'soc5200' for the -parent node of on chip devices, and the root node should be its parent. - -Child nodes are typically named after the configured function. ie. -the FEC node is named 'ethernet', and a PSC in uart mode is named 'serial'. - -2. device_type property ------------------------ -similar to the node name convention above; the device_type reflects the -configured function of a device. ie. 'serial' for a uart and 'spi' for -an spi controller. However, while node names *should* reflect the -configured function, device_type *must* match the configured function -exactly. - -3. compatible property ----------------------- -Since device_type isn't enough to match devices to drivers, there also -needs to be a naming convention for the compatible property. Compatible -is an list of device descriptions sorted from specific to generic. For -the mpc5200, the required format for each compatible value is --[-]. The OS should be able to match a device driver -to the device based solely on the compatible value. If two drivers -match on the compatible list; the 'most compatible' driver should be -selected. - -The split between the MPC5200 and the MPC5200B leaves a bit of a -conundrum. How should the compatible property be set up to provide -maximum compatibility information; but still accurately describe the -chip? For the MPC5200; the answer is easy. Most of the SoC devices -originally appeared on the MPC5200. Since they didn't exist anywhere -else; the 5200 compatible properties will contain only one item; -"mpc5200-". - -The 5200B is almost the same as the 5200, but not quite. It fixes -silicon bugs and it adds a small number of enhancements. Most of the -devices either provide exactly the same interface as on the 5200. A few -devices have extra functions but still have a backwards compatible mode. -To express this information as completely as possible, 5200B device trees -should have two items in the compatible list; -"mpc5200b-\0mpc5200-". It is *strongly* recommended -that 5200B device trees follow this convention (instead of only listing -the base mpc5200 item). - -If another chip appear on the market with one of the mpc5200 SoC -devices, then the compatible list should include mpc5200-. - -ie. ethernet on mpc5200: compatible = "mpc5200-ethernet" - ethernet on mpc5200b: compatible = "mpc5200b-ethernet\0mpc5200-ethernet" - -Modal devices, like PSCs, also append the configured function to the -end of the compatible field. ie. A PSC in i2s mode would specify -"mpc5200-psc-i2s", not "mpc5200-i2s". This convention is chosen to -avoid naming conflicts with non-psc devices providing the same -function. For example, "mpc5200-spi" and "mpc5200-psc-spi" describe -the mpc5200 simple spi device and a PSC spi mode respectively. - -If the soc device is more generic and present on other SOCs, the -compatible property can specify the more generic device type also. - -ie. mscan: compatible = "mpc5200-mscan\0fsl,mscan"; - -At the time of writing, exact chip may be either 'mpc5200' or -'mpc5200b'. - -Device drivers should always try to match as generically as possible. - -III - Structure -=============== -The device tree for an mpc5200 board follows the structure defined in -booting-without-of.txt with the following additional notes: - -0) the root node ----------------- -Typical root description node; see booting-without-of - -1) The cpus node ----------------- -The cpus node follows the basic layout described in booting-without-of. -The bus-frequency property holds the XLB bus frequency -The clock-frequency property holds the core frequency - -2) The memory node ------------------- -Typical memory description node; see booting-without-of. - -3) The soc5200 node -------------------- -This node describes the on chip SOC peripherals. Every mpc5200 based -board will have this node, and as such there is a common naming -convention for SOC devices. - -Required properties: -name type description ----- ---- ----------- -device_type string must be "soc" -ranges int should be <0 baseaddr baseaddr+10000> -reg int must be -compatible string mpc5200: "mpc5200-soc" - mpc5200b: "mpc5200b-soc\0mpc5200-soc" -system-frequency int Fsystem frequency; source of all - other clocks. -bus-frequency int IPB bus frequency in HZ. Clock rate - used by most of the soc devices. -#interrupt-cells int must be <3>. - -Recommended properties: -name type description ----- ---- ----------- -model string Exact model of the chip; - ie: model="fsl,mpc5200" -revision string Silicon revision of chip - ie: revision="M08A" - -The 'model' and 'revision' properties are *strongly* recommended. Having -them presence acts as a bit of a safety net for working around as yet -undiscovered bugs on one version of silicon. For example, device drivers -can use the model and revision properties to decide if a bug fix should -be turned on. - -4) soc5200 child nodes ----------------------- -Any on chip SOC devices available to Linux must appear as soc5200 child nodes. - -Note: The tables below show the value for the mpc5200. A mpc5200b device -tree should use the "mpc5200b-\0mpc5200- form. - -Required soc5200 child nodes: -name device_type compatible Description ----- ----------- ---------- ----------- -cdm@ cdm mpc5200-cmd Clock Distribution -pic@ interrupt-controller mpc5200-pic need an interrupt - controller to boot -bestcomm@ dma-controller mpc5200-bestcomm 5200 pic also requires - the bestcomm device - -Recommended soc5200 child nodes; populate as needed for your board -name device_type compatible Description ----- ----------- ---------- ----------- -gpt@ gpt fsl,mpc5200-gpt General purpose timers -gpt@ gpt fsl,mpc5200-gpt-gpio General purpose - timers in GPIO mode -gpio@ fsl,mpc5200-gpio MPC5200 simple gpio - controller -gpio@ fsl,mpc5200-gpio-wkup MPC5200 wakeup gpio - controller -rtc@ rtc mpc5200-rtc Real time clock -mscan@ mscan mpc5200-mscan CAN bus controller -pci@ pci mpc5200-pci PCI bridge -serial@ serial mpc5200-psc-uart PSC in serial mode -i2s@ sound mpc5200-psc-i2s PSC in i2s mode -ac97@ sound mpc5200-psc-ac97 PSC in ac97 mode -spi@ spi mpc5200-psc-spi PSC in spi mode -irda@ irda mpc5200-psc-irda PSC in IrDA mode -spi@ spi mpc5200-spi MPC5200 spi device -ethernet@ network mpc5200-fec MPC5200 ethernet device -ata@ ata mpc5200-ata IDE ATA interface -i2c@ i2c mpc5200-i2c I2C controller -usb@ usb-ohci-be mpc5200-ohci,ohci-be USB controller -xlb@ xlb mpc5200-xlb XLB arbitrator - -Important child node properties -name type description ----- ---- ----------- -cell-index int When multiple devices are present, is the - index of the device in the hardware (ie. There - are 6 PSC on the 5200 numbered PSC1 to PSC6) - PSC1 has 'cell-index = <0>' - PSC4 has 'cell-index = <3>' - -5) General Purpose Timer nodes (child of soc5200 node) -On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board -design supports the internal wdt, then the device node for GPT0 should -include the empty property 'fsl,has-wdt'. - -6) PSC nodes (child of soc5200 node) -PSC nodes can define the optional 'port-number' property to force assignment -order of serial ports. For example, PSC5 might be physically connected to -the port labeled 'COM1' and PSC1 wired to 'COM1'. In this case, PSC5 would -have a "port-number = <0>" property, and PSC1 would have "port-number = <1>". - -PSC in i2s mode: The mpc5200 and mpc5200b PSCs are not compatible when in -i2s mode. An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the -compatible field. - -7) GPIO controller nodes -Each GPIO controller node should have the empty property gpio-controller and -#gpio-cells set to 2. First cell is the GPIO number which is interpreted -according to the bit numbers in the GPIO control registers. The second cell -is for flags which is currently unsused. - -8) FEC nodes -The FEC node can specify one of the following properties to configure -the MII link: -"fsl,7-wire-mode" - An empty property that specifies the link uses 7-wire - mode instead of MII -"current-speed" - Specifies that the MII should be configured for a fixed - speed. This property should contain two cells. The - first cell specifies the speed in Mbps and the second - should be '0' for half duplex and '1' for full duplex -"phy-handle" - Contains a phandle to an Ethernet PHY. - -IV - Extra Notes -================ - -1. Interrupt mapping --------------------- -The mpc5200 pic driver splits hardware IRQ numbers into two levels. The -split reflects the layout of the PIC hardware itself, which groups -interrupts into one of three groups; CRIT, MAIN or PERP. Also, the -Bestcomm dma engine has it's own set of interrupt sources which are -cascaded off of peripheral interrupt 0, which the driver interprets as a -fourth group, SDMA. - -The interrupts property for device nodes using the mpc5200 pic consists -of three cells; - - L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3] - L2 := interrupt number; directly mapped from the value in the - "ICTL PerStat, MainStat, CritStat Encoded Register" - level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3] - -2. Shared registers -------------------- -Some SoC devices share registers between them. ie. the i2c devices use -a single clock control register, and almost all device are affected by -the port_config register. Devices which need to manipulate shared regs -should look to the parent SoC node. The soc node is responsible -for arbitrating all shared register access. -- cgit v1.2.2 From cbb5901b904e122139e97c6f4caed9b1f13c3455 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 2 Feb 2009 13:02:31 +0100 Subject: block: add text file detailing queue/ sysfs files Signed-off-by: Jens Axboe --- Documentation/block/queue-sysfs.txt | 63 +++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 Documentation/block/queue-sysfs.txt (limited to 'Documentation') diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt new file mode 100644 index 000000000000..e164403f60e1 --- /dev/null +++ b/Documentation/block/queue-sysfs.txt @@ -0,0 +1,63 @@ +Queue sysfs files +================= + +This text file will detail the queue files that are located in the sysfs tree +for each block device. Note that stacked devices typically do not export +any settings, since their queue merely functions are a remapping target. +These files are the ones found in the /sys/block/xxx/queue/ directory. + +Files denoted with a RO postfix are readonly and the RW postfix means +read-write. + +hw_sector_size (RO) +------------------- +This is the hardware sector size of the device, in bytes. + +max_hw_sectors_kb (RO) +---------------------- +This is the maximum number of kilobytes supported in a single data transfer. + +max_sectors_kb (RW) +------------------- +This is the maximum number of kilobytes that the block layer will allow +for a filesystem request. Must be smaller than or equal to the maximum +size allowed by the hardware. + +nomerges (RW) +------------- +This enables the user to disable the lookup logic involved with IO merging +requests in the block layer. Merging may still occur through a direct +1-hit cache, since that comes for (almost) free. The IO scheduler will not +waste cycles doing tree/hash lookups for merges if nomerges is 1. Defaults +to 0, enabling all merges. + +nr_requests (RW) +---------------- +This controls how many requests may be allocated in the block layer for +read or write requests. Note that the total allocated number may be twice +this amount, since it applies only to reads or writes (not the accumulated +sum). + +read_ahead_kb (RW) +------------------ +Maximum number of kilobytes to read-ahead for filesystems on this block +device. + +rq_affinity (RW) +---------------- +If this option is enabled, the block layer will migrate request completions +to the CPU that originally submitted the request. For some workloads +this provides a significant reduction in CPU cycles due to caching effects. + +scheduler (RW) +-------------- +When read, this file will display the current and available IO schedulers +for this block device. The currently active IO scheduler will be enclosed +in [] brackets. Writing an IO scheduler name to this file will switch +control of this block device to that new IO scheduler. Note that writing +an IO scheduler name to this file will attempt to load that IO scheduler +module, if it isn't already present in the system. + + + +Jens Axboe , February 2009 -- cgit v1.2.2