diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DMA-mapping.txt | 4 | ||||
| -rw-r--r-- | Documentation/HOWTO | 2 | ||||
| -rw-r--r-- | Documentation/block/00-INDEX | 20 | ||||
| -rw-r--r-- | Documentation/block/as-iosched.txt | 21 | ||||
| -rw-r--r-- | Documentation/block/biodoc.txt | 4 | ||||
| -rw-r--r-- | Documentation/block/deadline-iosched.txt | 25 | ||||
| -rw-r--r-- | Documentation/block/ioprio.txt | 2 | ||||
| -rw-r--r-- | Documentation/block/request.txt | 2 | ||||
| -rw-r--r-- | Documentation/block/switching-sched.txt | 21 | ||||
| -rw-r--r-- | Documentation/cachetlb.txt | 6 | ||||
| -rw-r--r-- | Documentation/cpusets.txt | 24 | ||||
| -rw-r--r-- | Documentation/fb/00-INDEX | 46 | ||||
| -rw-r--r-- | Documentation/fb/uvesafb.txt | 188 | ||||
| -rw-r--r-- | Documentation/filesystems/Locking | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 51 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 10 | ||||
| -rw-r--r-- | Documentation/spi/spi-summary | 25 | ||||
| -rw-r--r-- | Documentation/spi/spidev_test.c | 6 | ||||
| -rw-r--r-- | Documentation/vm/numa_memory_policy.txt | 33 | ||||
| -rw-r--r-- | Documentation/x86_64/mm.txt | 1 |
20 files changed, 397 insertions, 103 deletions
diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt index e07f2530326b..3c8ae020b6a7 100644 --- a/Documentation/DMA-mapping.txt +++ b/Documentation/DMA-mapping.txt @@ -514,7 +514,7 @@ With scatterlists, you map a region gathered from several regions by: int i, count = pci_map_sg(dev, sglist, nents, direction); struct scatterlist *sg; - for (i = 0, sg = sglist; i < count; i++, sg++) { + for_each_sg(sglist, sg, count, i) { hw_address[i] = sg_dma_address(sg); hw_len[i] = sg_dma_len(sg); } @@ -782,5 +782,5 @@ following people: Jay Estabrook <Jay.Estabrook@compaq.com> Thomas Sailer <sailer@ife.ee.ethz.ch> Andrea Arcangeli <andrea@suse.de> - Jens Axboe <axboe@suse.de> + Jens Axboe <jens.axboe@oracle.com> David Mosberger-Tang <davidm@hpl.hp.com> diff --git a/Documentation/HOWTO b/Documentation/HOWTO index c64e969dc33b..dceb30921498 100644 --- a/Documentation/HOWTO +++ b/Documentation/HOWTO @@ -330,7 +330,7 @@ Here is a list of some of the different kernel trees available: - ACPI development tree, Len Brown <len.brown@intel.com> git.kernel.org:/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6.git - - Block development tree, Jens Axboe <axboe@suse.de> + - Block development tree, Jens Axboe <jens.axboe@oracle.com> git.kernel.org:/pub/scm/linux/kernel/git/axboe/linux-2.6-block.git - DRM development tree, Dave Airlie <airlied@linux.ie> diff --git a/Documentation/block/00-INDEX b/Documentation/block/00-INDEX new file mode 100644 index 000000000000..961a0513f8c3 --- /dev/null +++ b/Documentation/block/00-INDEX @@ -0,0 +1,20 @@ +00-INDEX + - This file +as-iosched.txt + - Anticipatory IO scheduler +barrier.txt + - I/O Barriers +biodoc.txt + - Notes on the Generic Block Layer Rewrite in Linux 2.5 +capability.txt + - Generic Block Device Capability (/sys/block/<disk>/capability) +deadline-iosched.txt + - Deadline IO scheduler tunables +ioprio.txt + - Block io priorities (in CFQ scheduler) +request.txt + - The members of struct request (in include/linux/blkdev.h) +stat.txt + - Block layer statistics in /sys/block/<dev>/stat +switching-sched.txt + - Switching I/O schedulers at runtime diff --git a/Documentation/block/as-iosched.txt b/Documentation/block/as-iosched.txt index a598fe10a297..738b72be128e 100644 --- a/Documentation/block/as-iosched.txt +++ b/Documentation/block/as-iosched.txt @@ -20,15 +20,10 @@ actually has a head for each physical device in the logical RAID device. However, setting the antic_expire (see tunable parameters below) produces very similar behavior to the deadline IO scheduler. - Selecting IO schedulers ----------------------- -To choose IO schedulers at boot time, use the argument 'elevator=deadline'. -'noop', 'as' and 'cfq' (the default) are also available. IO schedulers are -assigned globally at boot time only presently. It's also possible to change -the IO scheduler for a determined device on the fly, as described in -Documentation/block/switching-sched.txt. - +Refer to Documentation/block/switching-sched.txt for information on +selecting an io scheduler on a per-device basis. Anticipatory IO scheduler Policies ---------------------------------- @@ -115,7 +110,7 @@ statistics (average think time, average seek distance) on the process that submitted the just completed request are examined. If it seems likely that that process will submit another request soon, and that request is likely to be near the just completed request, then the IO -scheduler will stop dispatching more read requests for up time (antic_expire) +scheduler will stop dispatching more read requests for up to (antic_expire) milliseconds, hoping that process will submit a new request near the one that just completed. If such a request is made, then it is dispatched immediately. If the antic_expire wait time expires, then the IO scheduler @@ -165,3 +160,13 @@ The parameters are: for big seek time devices though not a linear correspondence - most processes have only a few ms thinktime. +In addition to the tunables above there is a read-only file named est_time +which, when read, will show: + + - The probability of a task exiting without a cooperating task + submitting an anticipated IO. + + - The current mean think time. + + - The seek distance used to determine if an incoming IO is better. + diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index dc3f49e3e539..93f223b9723f 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -2,7 +2,7 @@ ===================================================== Notes Written on Jan 15, 2002: - Jens Axboe <axboe@suse.de> + Jens Axboe <jens.axboe@oracle.com> Suparna Bhattacharya <suparna@in.ibm.com> Last Updated May 2, 2002 @@ -21,7 +21,7 @@ Credits: --------- 2.5 bio rewrite: - Jens Axboe <axboe@suse.de> + Jens Axboe <jens.axboe@oracle.com> Many aspects of the generic block layer redesign were driven by and evolved over discussions, prior patches and the collective experience of several diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt index be08ffd1e9b8..c23cab13c3d1 100644 --- a/Documentation/block/deadline-iosched.txt +++ b/Documentation/block/deadline-iosched.txt @@ -5,16 +5,10 @@ This little file attempts to document how the deadline io scheduler works. In particular, it will clarify the meaning of the exposed tunables that may be of interest to power users. -Each io queue has a set of io scheduler tunables associated with it. These -tunables control how the io scheduler works. You can find these entries -in: - -/sys/block/<device>/queue/iosched - -assuming that you have sysfs mounted on /sys. If you don't have sysfs mounted, -you can do so by typing: - -# mount none /sys -t sysfs +Selecting IO schedulers +----------------------- +Refer to Documentation/block/switching-sched.txt for information on +selecting an io scheduler on a per-device basis. ******************************************************************************** @@ -41,14 +35,11 @@ fifo_batch When a read request expires its deadline, we must move some requests from the sorted io scheduler list to the block device dispatch queue. fifo_batch -controls how many requests we move, based on the cost of each request. A -request is either qualified as a seek or a stream. The io scheduler knows -the last request that was serviced by the drive (or will be serviced right -before this one). See seek_cost and stream_unit. +controls how many requests we move. -write_starved (number of dispatches) -------------- +writes_starved (number of dispatches) +-------------- When we have to move requests from the io scheduler queue to the block device dispatch queue, we always give a preference to reads. However, we @@ -73,6 +64,6 @@ that comes at basically 0 cost we leave that on. We simply disable the rbtree front sector lookup when the io scheduler merge function is called. -Nov 11 2002, Jens Axboe <axboe@suse.de> +Nov 11 2002, Jens Axboe <jens.axboe@oracle.com> diff --git a/Documentation/block/ioprio.txt b/Documentation/block/ioprio.txt index 35e516b0b8a9..8ed8c59380b4 100644 --- a/Documentation/block/ioprio.txt +++ b/Documentation/block/ioprio.txt @@ -180,4 +180,4 @@ int main(int argc, char *argv[]) ---> snip ionice.c tool <--- -March 11 2005, Jens Axboe <axboe@suse.de> +March 11 2005, Jens Axboe <jens.axboe@oracle.com> diff --git a/Documentation/block/request.txt b/Documentation/block/request.txt index fff58acb40a3..754e104ed369 100644 --- a/Documentation/block/request.txt +++ b/Documentation/block/request.txt @@ -1,7 +1,7 @@ struct request documentation -Jens Axboe <axboe@suse.de> 27/05/02 +Jens Axboe <jens.axboe@oracle.com> 27/05/02 1.0 Index diff --git a/Documentation/block/switching-sched.txt b/Documentation/block/switching-sched.txt index 5fa130a67531..634c952e1964 100644 --- a/Documentation/block/switching-sched.txt +++ b/Documentation/block/switching-sched.txt @@ -1,3 +1,18 @@ +To choose IO schedulers at boot time, use the argument 'elevator=deadline'. +'noop', 'as' and 'cfq' (the default) are also available. IO schedulers are +assigned globally at boot time only presently. + +Each io queue has a set of io scheduler tunables associated with it. These +tunables control how the io scheduler works. You can find these entries +in: + +/sys/block/<device>/queue/iosched + +assuming that you have sysfs mounted on /sys. If you don't have sysfs mounted, +you can do so by typing: + +# mount none /sys -t sysfs + As of the Linux 2.6.10 kernel, it is now possible to change the IO scheduler for a given block device on the fly (thus making it possible, for instance, to set the CFQ scheduler for the system default, but @@ -20,3 +35,9 @@ noop anticipatory deadline [cfq] # echo anticipatory > /sys/block/hda/queue/scheduler # cat /sys/block/hda/queue/scheduler noop [anticipatory] deadline cfq + +Each io queue has a set of io scheduler tunables associated with it. These +tunables control how the io scheduler works. You can find these entries +in: + +/sys/block/<device>/queue/iosched diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt index 866b76139420..552cabac0608 100644 --- a/Documentation/cachetlb.txt +++ b/Documentation/cachetlb.txt @@ -133,12 +133,6 @@ changes occur: The ia64 sn2 platform is one example of a platform that uses this interface. -8) void lazy_mmu_prot_update(pte_t pte) - This interface is called whenever the protection on - any user PTEs change. This interface provides a notification - to architecture specific code to take appropriate action. - - Next, we have the cache flushing interfaces. In general, when Linux is changing an existing virtual-->physical mapping to a new value, the sequence will be in one of the following forms: diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index f2c0a6842930..ec9de6917f01 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -35,7 +35,8 @@ CONTENTS: ---------------------- Cpusets provide a mechanism for assigning a set of CPUs and Memory -Nodes to a set of tasks. +Nodes to a set of tasks. In this document "Memory Node" refers to +an on-line node that contains memory. Cpusets constrain the CPU and Memory placement of tasks to only the resources within a tasks current cpuset. They form a nested @@ -86,9 +87,6 @@ This can be especially valuable on: and a database), or * NUMA systems running large HPC applications with demanding performance characteristics. - * Also cpu_exclusive cpusets are useful for servers running orthogonal - workloads such as RT applications requiring low latency and HPC - applications that are throughput sensitive These subsets, or "soft partitions" must be able to be dynamically adjusted, as the job mix changes, without impacting other concurrently @@ -131,8 +129,6 @@ Cpusets extends these two mechanisms as follows: - A cpuset may be marked exclusive, which ensures that no other cpuset (except direct ancestors and descendents) may contain any overlapping CPUs or Memory Nodes. - Also a cpu_exclusive cpuset would be associated with a sched - domain. - You can list all the tasks (by pid) attached to any cpuset. The implementation of cpusets requires a few, simple hooks @@ -144,9 +140,6 @@ into the rest of the kernel, none in performance critical paths: allowed in that tasks cpuset. - in sched.c migrate_all_tasks(), to keep migrating tasks within the CPUs allowed by their cpuset, if possible. - - in sched.c, a new API partition_sched_domains for handling - sched domain changes associated with cpu_exclusive cpusets - and related changes in both sched.c and arch/ia64/kernel/domain.c - in the mbind and set_mempolicy system calls, to mask the requested Memory Nodes by what's allowed in that tasks cpuset. - in page_alloc.c, to restrict memory to allowed nodes. @@ -220,8 +213,8 @@ and name space for cpusets, with a minimum of additional kernel code. The cpus and mems files in the root (top_cpuset) cpuset are read-only. The cpus file automatically tracks the value of cpu_online_map using a CPU hotplug notifier, and the mems file -automatically tracks the value of node_online_map using the -cpuset_track_online_nodes() hook. +automatically tracks the value of node_states[N_MEMORY]--i.e., +nodes with memory--using the cpuset_track_online_nodes() hook. 1.4 What are exclusive cpusets ? @@ -231,15 +224,6 @@ If a cpuset is cpu or mem exclusive, no other cpuset, other than a direct ancestor or descendent, may share any of the same CPUs or Memory Nodes. -A cpuset that is cpu_exclusive has a scheduler (sched) domain -associated with it. The sched domain consists of all CPUs in the -current cpuset that are not part of any exclusive child cpusets. -This ensures that the scheduler load balancing code only balances -against the CPUs that are in the sched domain as defined above and -not all of the CPUs in the system. This removes any overhead due to -load balancing code trying to pull tasks outside of the cpu_exclusive -cpuset only to be prevented by the tasks' cpus_allowed mask. - A cpuset that is mem_exclusive restricts kernel allocations for page, buffer and other data commonly shared by the kernel across multiple users. All cpusets, whether mem_exclusive or not, restrict diff --git a/Documentation/fb/00-INDEX b/Documentation/fb/00-INDEX index 92e89aeef52e..caabbd395e61 100644 --- a/Documentation/fb/00-INDEX +++ b/Documentation/fb/00-INDEX @@ -5,21 +5,49 @@ please mail me. 00-INDEX - this file +arkfb.txt + - info on the fbdev driver for ARK Logic chips. +aty128fb.txt + - info on the ATI Rage128 frame buffer driver. +cirrusfb.txt + - info on the driver for Cirrus Logic chipsets. +cyblafb/ + - directory with documentation files related to the cyblafb driver. +deferred_io.txt + - an introduction to deferred IO. +fbcon.txt + - intro to and usage guide for the framebuffer console (fbcon). framebuffer.txt - - introduction to frame buffer devices + - introduction to frame buffer devices. +imacfb.txt + - info on the generic EFI platform driver for Intel based Macs. +intel810.txt + - documentation for the Intel 810/815 framebuffer driver. +intelfb.txt + - docs for Intel 830M/845G/852GM/855GM/865G/915G/945G fb driver. internals.txt - - quick overview of frame buffer device internals + - quick overview of frame buffer device internals. +matroxfb.txt + - info on the Matrox framebuffer driver for Alpha, Intel and PPC. modedb.txt - - info on the video mode database -aty128fb.txt - - info on the ATI Rage128 frame buffer driver -clgenfb.txt - - info on the Cirrus Logic frame buffer driver + - info on the video mode database. matroxfb.txt - - info on the Matrox frame buffer driver + - info on the Matrox frame buffer driver. pvr2fb.txt - - info on the PowerVR 2 frame buffer driver + - info on the PowerVR 2 frame buffer driver. +pxafb.txt + - info on the driver for the PXA25x LCD controller. +s3fb.txt + - info on the fbdev driver for S3 Trio/Virge chips. +sa1100fb.txt + - information about the driver for the SA-1100 LCD controller. +sisfb.txt + - info on the framebuffer device driver for various SiS chips. +sstfb.txt + - info on the frame buffer driver for 3dfx' Voodoo Graphics boards. tgafb.txt - info on the TGA (DECChip 21030) frame buffer driver vesafb.txt - info on the VESA frame buffer device +vt8623fb.txt + - info on the fb driver for the graphics core in VIA VT8623 chipsets. diff --git a/Documentation/fb/uvesafb.txt b/Documentation/fb/uvesafb.txt new file mode 100644 index 000000000000..bcfc233a0080 --- /dev/null +++ b/Documentation/fb/uvesafb.txt @@ -0,0 +1,188 @@ + +uvesafb - A Generic Driver for VBE2+ compliant video cards +========================================================== + +1. Requirements +--------------- + +uvesafb should work with any video card that has a Video BIOS compliant +with the VBE 2.0 standard. + +Unlike other drivers, uvesafb makes use of a userspace helper called +v86d. v86d is used to run the x86 Video BIOS code in a simulated and +controlled environment. This allows uvesafb to function on arches other +than x86. Check the v86d documentation for a list of currently supported +arches. + +v86d source code can be downloaded from the following website: + http://dev.gentoo.org/~spock/projects/uvesafb + +Please refer to the v86d documentation for detailed configuration and +installation instructions. + +Note that the v86d userspace helper has to be available at all times in +order for uvesafb to work properly. If you want to use uvesafb during +early boot, you will have to include v86d into an initramfs image, and +either compile it into the kernel or use it as an initrd. + +2. Caveats and limitations +-------------------------- + +uvesafb is a _generic_ driver which supports a wide variety of video +cards, but which is ultimately limited by the Video BIOS interface. +The most important limitations are: + +- Lack of any type of acceleration. +- A strict and limited set of supported video modes. Often the native + or most optimal resolution/refresh rate for your setup will not work + with uvesafb, simply because the Video BIOS doesn't support the + video mode you want to use. This can be especially painful with + widescreen panels, where native video modes don't have the 4:3 aspect + ratio, which is what most BIOS-es are limited to. +- Adjusting the refresh rate is only possible with a VBE 3.0 compliant + Video BIOS. Note that many nVidia Video BIOS-es claim to be VBE 3.0 + compliant, while they simply ignore any refresh rate settings. + +3. Configuration +---------------- + +uvesafb can be compiled either as a module, or directly into the kernel. +In both cases it supports the same set of configuration options, which +are either given on the kernel command line or as module parameters, e.g.: + + video=uvesafb:1024x768-32,mtrr:3,ywrap (compiled into the kernel) + + # modprobe uvesafb mode=1024x768-32 mtrr=3 scroll=ywrap (module) + +Accepted options: + +ypan Enable display panning using the VESA protected mode + interface. The visible screen is just a window of the + video memory, console scrolling is done by changing the + start of the window. Available on x86 only. + +ywrap Same as ypan, but assumes your gfx board can wrap-around + the video memory (i.e. starts reading from top if it + reaches the end of video memory). Faster than ypan. + Available on x86 only. + +redraw Scroll by redrawing the affected part of the screen, this + is the safe (and slow) default. + +(If you're using uvesafb as a module, the above three options are + used a parameter of the scroll option, e.g. scroll=ypan.) + +vgapal Use the standard VGA registers for palette changes. + +pmipal Use the protected mode interface for palette changes. + This is the default if the protected mode interface is + available. Available on x86 only. + +mtrr:n Setup memory type range registers for the framebuffer + where n: + 0 - disabled (equivalent to nomtrr) (default) + 1 - uncachable + 2 - write-back + 3 - write-combining + 4 - write-through + + If you see the following in dmesg, choose the type that matches + the old one. In this example, use "mtrr:2". +... +mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining +... + +nomtrr Do not use memory type range registers. + +vremap:n + Remap 'n' MiB of video RAM. If 0 or not specified, remap memory + according to video mode. + +vtotal:n + If the video BIOS of your card incorrectly determines the total + amount of video RAM, use this option to override the BIOS (in MiB). + +<mode> The mode you want to set, in the standard modedb format. Refer to + modedb.txt for a detailed description. When uvesafb is compiled as + a module, the mode string should be provided as a value of the + 'mode' option. + +vbemode:x + Force the use of VBE mode x. The mode will only be set if it's + found in the VBE-provided list of supported modes. + NOTE: The mode number 'x' should be specified in VESA mode number + notation, not the Linux kernel one (eg. 257 instead of 769). + HINT: If you use this option because normal <mode> parameter does + not work for you and you use a X server, you'll probably want to + set the 'nocrtc' option to ensure that the video mode is properly + restored after console <-> X switches. + +nocrtc Do not use CRTC timings while setting the video mode. This option + has any effect only if the Video BIOS is VBE 3.0 compliant. Use it + if you have problems with modes set the standard way. Note that + using this option implies that any refresh rate adjustments will + be ignored and the refresh rate will stay at your BIOS default (60 Hz). + +noedid Do not try to fetch and use EDID-provided modes. + +noblank Disable hardware blanking. + +v86d:path + Set path to the v86d executable. This option is only available as + a module parameter, and not as a part of the video= string. If you + need to use it and have uvesafb built into the kernel, use + uvesafb.v86d="path". + +Additionally, the following parameters may be provided. They all override the +EDID-provided values and BIOS defaults. Refer to your monitor's specs to get +the correct values for maxhf, maxvf and maxclk for your hardware. + +maxhf:n Maximum horizontal frequency (in kHz). +maxvf:n Maximum vertical frequency (in Hz). +maxclk:n Maximum pixel clock (in MHz). + +4. The sysfs interface +---------------------- + +uvesafb provides several sysfs nodes for configurable parameters and +additional information. + +Driver attributes: + +/sys/bus/platform/drivers/uvesafb + - v86d (default: /sbin/v86d) + Path to the v86d executable. v86d is started by uvesafb + if an instance of the daemon isn't already running. + +Device attributes: + +/sys/bus/platform/drivers/uvesafb/uvesafb.0 + - nocrtc + Use the default refresh rate (60 Hz) if set to 1. + + - oem_product_name + - oem_product_rev + - oem_string + - oem_vendor + Information about the card and its maker. + + - vbe_modes + A list of video modes supported by the Video BIOS along with their + VBE mode numbers in hex. + + - vbe_version + A BCD value indicating the implemented VBE standard. + +5. Miscellaneous +---------------- + +Uvesafb will set a video mode with the default refresh rate and timings +from the Video BIOS if you set pixclock to 0 in fb_var_screeninfo. + + +-- + Michal Januszewski <spock@gentoo.org> + Last updated: 2007-06-16 + + Documentation of the uvesafb options is loosely based on vesafb.txt. + diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index f0f825808ca4..fe26cc978523 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -178,15 +178,18 @@ prototypes: locking rules: All except set_page_dirty may block - BKL PageLocked(page) + BKL PageLocked(page) i_sem writepage: no yes, unlocks (see below) readpage: no yes, unlocks sync_page: no maybe writepages: no set_page_dirty no no readpages: no -prepare_write: no yes -commit_write: no yes +prepare_write: no yes yes +commit_write: no yes yes +write_begin: no locks the page yes +write_end: no yes, unlocks yes +perform_write: no n/a yes bmap: yes invalidatepage: no yes releasepage: no yes diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 045f3e055a28..6f8e16e3d6c0 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -537,6 +537,12 @@ struct address_space_operations { struct list_head *pages, unsigned nr_pages); int (*prepare_write)(struct file *, struct page *, unsigned, unsigned); int (*commit_write)(struct file *, struct page *, unsigned, unsigned); + int (*write_begin)(struct file *, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata); + int (*write_end)(struct file *, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata); sector_t (*bmap)(struct address_space *, sector_t); int (*invalidatepage) (struct page *, unsigned long); int (*releasepage) (struct page *, int); @@ -615,11 +621,7 @@ struct address_space_operations { any basic-blocks on storage, then those blocks should be pre-read (if they haven't been read already) so that the updated blocks can be written out properly. - The page will be locked. If prepare_write wants to unlock the - page it, like readpage, may do so and return - AOP_TRUNCATED_PAGE. - In this case the prepare_write will be retried one the lock is - regained. + The page will be locked. Note: the page _must not_ be marked uptodate in this function (or anywhere else) unless it actually is uptodate right now. As @@ -633,6 +635,45 @@ struct address_space_operations { operations. It should avoid returning an error if possible - errors should have been handled by prepare_write. + write_begin: This is intended as a replacement for prepare_write. The + key differences being that: + - it returns a locked page (in *pagep) rather than being + given a pre locked page; + - it must be able to cope with short writes (where the + length passed to write_begin is greater than the number + of bytes copied into the page). + + Called by the generic buffered write code to ask the filesystem to + prepare to write len bytes at the given offset in the file. The + address_space should check that the write will be able to complete, + by allocating space if necessary and doing any other internal + housekeeping. If the write will update parts of any basic-blocks on + storage, then those blocks should be pre-read (if they haven't been + read already) so that the updated blocks can be written out properly. + + The filesystem must return the locked pagecache page for the specified + offset, in *pagep, for the caller to write into. + + flags is a field for AOP_FLAG_xxx flags, described in + include/linux/fs.h. + + A void * may be returned in fsdata, which then gets passed into + write_end. + + Returns 0 on success; < 0 on failure (which is the error code), in + which case write_end is not called. + + write_end: After a successful write_begin, and data copy, write_end must + be called. len is the original len passed to write_begin, and copied + is the amount that was able to be copied (copied == len is always true + if write_begin was called with the AOP_FLAG_UNINTERRUPTIBLE flag). + + The filesystem must take care of unlocking the page and releasing it + refcount, and updating i_size. + + Returns < 0 on failure, otherwise the number of bytes (<= 'copied') + that were able to be copied into pagecache. + bmap: called by the VFS to map a logical block offset within object to physical block number. This method is used by the FIBMAP ioctl and for working with swap-files. To be able to swap to diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 085e4a095eaa..eb247997f679 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -349,6 +349,11 @@ and is between 256 and 4096 characters. It is defined in the file blkmtd_bs= blkmtd_count= + boot_delay= Milliseconds to delay each printk during boot. + Values larger than 10 seconds (10000) are changed to + no delay (0). + Format: integer + bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) bttv.radio= Most important insmod options are available as kernel args too. @@ -906,6 +911,11 @@ and is between 256 and 4096 characters. It is defined in the file n must be a power of two. The default size is set in the kernel config file. + logo.nologo [FB] Disables display of the built-in Linux logo. + This may be used to provide more screen space for + kernel log messages and is useful when debugging + kernel boot problems. + lp=0 [LP] Specify parallel ports to use, e.g, lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses lp=reset first parallel port). 'lp=0' disables the diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index 76ea6c837be5..8861e47e5a2d 100644 --- a/Documentation/spi/spi-summary +++ b/Documentation/spi/spi-summary @@ -156,21 +156,29 @@ using the driver model to connect controller and protocol drivers using device tables provided by board specific initialization code. SPI shows up in sysfs in several locations: + /sys/devices/.../CTLR ... physical node for a given SPI controller + /sys/devices/.../CTLR/spiB.C ... spi_device on bus "B", chipselect C, accessed through CTLR. + /sys/bus/spi/devices/spiB.C ... symlink to that physical + .../CTLR/spiB.C device + /sys/devices/.../CTLR/spiB.C/modalias ... identifies the driver that should be used with this device (for hotplug/coldplug) - /sys/bus/spi/devices/spiB.C ... symlink to the physical - spiB.C device - /sys/bus/spi/drivers/D ... driver for one or more spi*.* devices - /sys/class/spi_master/spiB ... class device for the controller - managing bus "B". All the spiB.* devices share the same + /sys/class/spi_master/spiB ... symlink (or actual device node) to + a logical node which could hold class related state for the + controller managing bus "B". All spiB.* devices share one physical SPI bus segment, with SCLK, MOSI, and MISO. +Note that the actual location of the controller's class state depends +on whether you enabled CONFIG_SYSFS_DEPRECATED or not. At this time, +the only class-specific state is the bus number ("B" in "spiB"), so +those /sys/class entries are only useful to quickly identify busses. + How does board-specific init code declare SPI devices? ------------------------------------------------------ @@ -337,7 +345,8 @@ SPI protocol drivers somewhat resemble platform device drivers: The driver core will autmatically attempt to bind this driver to any SPI device whose board_info gave a modalias of "CHIP". Your probe() code -might look like this unless you're creating a class_device: +might look like this unless you're creating a device which is managing +a bus (appearing under /sys/class/spi_master). static int __devinit CHIP_probe(struct spi_device *spi) { @@ -442,7 +451,7 @@ An SPI controller will probably be registered on the platform_bus; write a driver to bind to the device, whichever bus is involved. The main task of this type of driver is to provide an "spi_master". -Use spi_alloc_master() to allocate the master, and class_get_devdata() +Use spi_alloc_master() to allocate the master, and spi_master_get_devdata() to get the driver-private data allocated for that device. struct spi_master *master; @@ -452,7 +461,7 @@ to get the driver-private data allocated for that device. if (!master) return -ENODEV; - c = class_get_devdata(&master->cdev); + c = spi_master_get_devdata(master); The driver will initialize the fields of that spi_master, including the bus number (maybe the same as the platform device ID) and three methods diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c index 218e86215297..cf0e3ce0d526 100644 --- a/Documentation/spi/spidev_test.c +++ b/Documentation/spi/spidev_test.c @@ -29,7 +29,7 @@ static void pabort(const char *s) abort(); } -static char *device = "/dev/spidev1.1"; +static const char *device = "/dev/spidev1.1"; static uint8_t mode; static uint8_t bits = 8; static uint32_t speed = 500000; @@ -69,7 +69,7 @@ static void transfer(int fd) puts(""); } -void print_usage(char *prog) +void print_usage(const char *prog) { printf("Usage: %s [-DsbdlHOLC3]\n", prog); puts(" -D --device device to use (default /dev/spidev1.1)\n" @@ -88,7 +88,7 @@ void print_usage(char *prog) void parse_opts(int argc, char *argv[]) { while (1) { - static struct option lopts[] = { + static const struct option lopts[] = { { "device", 1, 0, 'D' }, { "speed", 1, 0, 's' }, { "delay", 1, 0, 'd' }, diff --git a/Documentation/vm/numa_memory_policy.txt b/Documentation/vm/numa_memory_policy.txt index 8242f52d0f22..dd4986497996 100644 --- a/Documentation/vm/numa_memory_policy.txt +++ b/Documentation/vm/numa_memory_policy.txt @@ -302,31 +302,30 @@ MEMORY POLICIES AND CPUSETS Memory policies work within cpusets as described above. For memory policies that require a node or set of nodes, the nodes are restricted to the set of -nodes whose memories are allowed by the cpuset constraints. If the -intersection of the set of nodes specified for the policy and the set of nodes -allowed by the cpuset is the empty set, the policy is considered invalid and -cannot be installed. +nodes whose memories are allowed by the cpuset constraints. If the nodemask +specified for the policy contains nodes that are not allowed by the cpuset, or +the intersection of the set of nodes specified for the policy and the set of +nodes with memory is the empty set, the policy is considered invalid +and cannot be installed. The interaction of memory policies and cpusets can be problematic for a couple of reasons: -1) the memory policy APIs take physical node id's as arguments. However, the - memory policy APIs do not provide a way to determine what nodes are valid - in the context where the application is running. An application MAY consult - the cpuset file system [directly or via an out of tree, and not generally - available, libcpuset API] to obtain this information, but then the - application must be aware that it is running in a cpuset and use what are - intended primarily as administrative APIs. - - However, as long as the policy specifies at least one node that is valid - in the controlling cpuset, the policy can be used. +1) the memory policy APIs take physical node id's as arguments. As mentioned + above, it is illegal to specify nodes that are not allowed in the cpuset. + The application must query the allowed nodes using the get_mempolicy() + API with the MPOL_F_MEMS_ALLOWED flag to determine the allowed nodes and + restrict itself to those nodes. However, the resources available to a + cpuset can be changed by the system administrator, or a workload manager + application, at any time. So, a task may still get errors attempting to + specify policy nodes, and must query the allowed memories again. 2) when tasks in two cpusets share access to a memory region, such as shared memory segments created by shmget() of mmap() with the MAP_ANONYMOUS and MAP_SHARED flags, and any of the tasks install shared policy on the region, only nodes whose memories are allowed in both cpusets may be used in the - policies. Again, obtaining this information requires "stepping outside" - the memory policy APIs, as well as knowing in what cpusets other task might - be attaching to the shared region, to use the cpuset information. + policies. Obtaining this information requires "stepping outside" the + memory policy APIs to use the cpuset information and requires that one + know in what cpusets other task might be attaching to the shared region. Furthermore, if the cpusets' allowed memory sets are disjoint, "local" allocation is the only valid policy. diff --git a/Documentation/x86_64/mm.txt b/Documentation/x86_64/mm.txt index f42798ed1c54..b89b6d2bebfa 100644 --- a/Documentation/x86_64/mm.txt +++ b/Documentation/x86_64/mm.txt @@ -9,6 +9,7 @@ ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space +ffffe20000000000 - ffffe2ffffffffff (=40 bits) virtual memory map (1TB) ... unused hole ... ffffffff80000000 - ffffffff82800000 (=40 MB) kernel text mapping, from phys 0 ... unused hole ... |