diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen | 61 | ||||
| -rw-r--r-- | Documentation/arm/Sharp-LH/LCDPanels | 59 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 13 | ||||
| -rw-r--r-- | Documentation/filesystems/inotify.txt | 130 | ||||
| -rw-r--r-- | Documentation/infiniband/ipoib.txt | 12 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 9 | ||||
| -rw-r--r-- | Documentation/memory-barriers.txt | 348 | ||||
| -rw-r--r-- | Documentation/networking/README.ipw2200 | 10 | ||||
| -rw-r--r-- | Documentation/networking/bonding.txt | 323 | ||||
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 7 | ||||
| -rw-r--r-- | Documentation/networking/netdevices.txt | 8 |
11 files changed, 778 insertions, 202 deletions
diff --git a/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen b/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen new file mode 100644 index 000000000000..1e6a23fdf2fc --- /dev/null +++ b/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen @@ -0,0 +1,61 @@ +README on the ADC/Touchscreen Controller +======================================== + +The LH79524 and LH7A404 include a built-in Analog to Digital +controller (ADC) that is used to process input from a touchscreen. +The driver only implements a four-wire touch panel protocol. + +The touchscreen driver is maintenance free except for the pen-down or +touch threshold. Some resistive displays and board combinations may +require tuning of this threshold. The driver exposes some of it's +internal state in the sys filesystem. If the kernel is configured +with it, CONFIG_SYSFS, and sysfs is mounted at /sys, there will be a +directory + + /sys/devices/platform/adc-lh7.0 + +containing these files. + + -r--r--r-- 1 root root 4096 Jan 1 00:00 samples + -rw-r--r-- 1 root root 4096 Jan 1 00:00 threshold + -r--r--r-- 1 root root 4096 Jan 1 00:00 threshold_range + +The threshold is the current touch threshold. It defaults to 750 on +most targets. + + # cat threshold + 750 + +The threshold_range contains the range of valid values for the +threshold. Values outside of this range will be silently ignored. + + # cat threshold_range + 0 1023 + +To change the threshold, write a value to the threshold file. + + # echo 500 > threshold + # cat threshold + 500 + +The samples file contains the most recently sampled values from the +ADC. There are 12. Below are typical of the last sampled values when +the pen has been released. The first two and last two samples are for +detecting whether or not the pen is down. The third through sixth are +X coordinate samples. The seventh through tenth are Y coordinate +samples. + + # cat samples + 1023 1023 0 0 0 0 530 529 530 529 1023 1023 + +To determine a reasonable threshold, press on the touch panel with an +appropriate stylus and read the values from samples. + + # cat samples + 1023 676 92 103 101 102 855 919 922 922 1023 679 + +The first and eleventh samples are discarded. Thus, the important +values are the second and twelfth which are used to determine if the +pen is down. When both are below the threshold, the driver registers +that the pen is down. When either is above the threshold, it +registers then pen is up. diff --git a/Documentation/arm/Sharp-LH/LCDPanels b/Documentation/arm/Sharp-LH/LCDPanels new file mode 100644 index 000000000000..fb1b21c2f2f4 --- /dev/null +++ b/Documentation/arm/Sharp-LH/LCDPanels @@ -0,0 +1,59 @@ +README on the LCD Panels +======================== + +Configuration options for several LCD panels, available from Logic PD, +are included in the kernel source. This README will help you +understand the configuration data and give you some guidance for +adding support for other panels if you wish. + + +lcd-panels.h +------------ + +There is no way, at present, to detect which panel is attached to the +system at runtime. Thus the kernel configuration is static. The file +arch/arm/mach-ld7a40x/lcd-panels.h (or similar) defines all of the +panel specific parameters. + +It should be possible for this data to be shared among several device +families. The current layout may be insufficiently general, but it is +amenable to improvement. + + +PIXEL_CLOCK +----------- + +The panel data sheets will give a range of acceptable pixel clocks. +The fundamental LCDCLK input frequency is divided down by a PCD +constant in field '.tim2'. It may happen that it is impossible to set +the pixel clock within this range. A clock which is too slow will +tend to flicker. For the highest quality image, set the clock as high +as possible. + + +MARGINS +------- + +These values may be difficult to glean from the panel data sheet. In +the case of the Sharp panels, the upper margin is explicitly called +out as a specific number of lines from the top of the frame. The +other values may not matter as much as the panels tend to +automatically center the image. + + +Sync Sense +---------- + +The sense of the hsync and vsync pulses may be called out in the data +sheet. On one panel, the sense of these pulses determine the height +of the visible region on the panel. Most of the Sharp panels use +negative sense sync pulses set by the TIM2_IHS and TIM2_IVS bits in +'.tim2'. + + +Pel Layout +---------- + +The Sharp color TFT panels are all configured for 16 bit direct color +modes. The amba-lcd driver sets the pel mode to 565 for 5 bits of +each red and blue and 6 bits of green. diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 43ab119963d5..f7293297f326 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -49,11 +49,11 @@ Who: Paul E. McKenney <paulmck@us.ibm.com> --------------------------- What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN -When: November 2005 +When: November 2006 Why: Deprecated in favour of the new ioctl-based rawiso interface, which is more efficient. You should really be using libraw1394 for raw1394 access anyway. -Who: Jody McIntyre <scjody@steamballoon.com> +Who: Jody McIntyre <scjody@modernduck.com> --------------------------- @@ -212,15 +212,6 @@ Who: Greg Kroah-Hartman <gregkh@suse.de> --------------------------- -What: Support for NEC DDB5074 and DDB5476 evaluation boards. -When: June 2006 -Why: Board specific code doesn't build anymore since ~2.6.0 and no - users have complained indicating there is no more need for these - boards. This should really be considered a last call. -Who: Ralf Baechle <ralf@linux-mips.org> - ---------------------------- - What: USB driver API moves to EXPORT_SYMBOL_GPL When: Febuary 2008 Files: include/linux/usb.h, drivers/usb/core/driver.c diff --git a/Documentation/filesystems/inotify.txt b/Documentation/filesystems/inotify.txt index 6d501903f68e..59a919f16144 100644 --- a/Documentation/filesystems/inotify.txt +++ b/Documentation/filesystems/inotify.txt @@ -69,17 +69,135 @@ Prototypes: int inotify_rm_watch (int fd, __u32 mask); -(iii) Internal Kernel Implementation +(iii) Kernel Interface -Each inotify instance is associated with an inotify_device structure. +Inotify's kernel API consists a set of functions for managing watches and an +event callback. + +To use the kernel API, you must first initialize an inotify instance with a set +of inotify_operations. You are given an opaque inotify_handle, which you use +for any further calls to inotify. + + struct inotify_handle *ih = inotify_init(my_event_handler); + +You must provide a function for processing events and a function for destroying +the inotify watch. + + void handle_event(struct inotify_watch *watch, u32 wd, u32 mask, + u32 cookie, const char *name, struct inode *inode) + + watch - the pointer to the inotify_watch that triggered this call + wd - the watch descriptor + mask - describes the event that occurred + cookie - an identifier for synchronizing events + name - the dentry name for affected files in a directory-based event + inode - the affected inode in a directory-based event + + void destroy_watch(struct inotify_watch *watch) + +You may add watches by providing a pre-allocated and initialized inotify_watch +structure and specifying the inode to watch along with an inotify event mask. +You must pin the inode during the call. You will likely wish to embed the +inotify_watch structure in a structure of your own which contains other +information about the watch. Once you add an inotify watch, it is immediately +subject to removal depending on filesystem events. You must grab a reference if +you depend on the watch hanging around after the call. + + inotify_init_watch(&my_watch->iwatch); + inotify_get_watch(&my_watch->iwatch); // optional + s32 wd = inotify_add_watch(ih, &my_watch->iwatch, inode, mask); + inotify_put_watch(&my_watch->iwatch); // optional + +You may use the watch descriptor (wd) or the address of the inotify_watch for +other inotify operations. You must not directly read or manipulate data in the +inotify_watch. Additionally, you must not call inotify_add_watch() more than +once for a given inotify_watch structure, unless you have first called either +inotify_rm_watch() or inotify_rm_wd(). + +To determine if you have already registered a watch for a given inode, you may +call inotify_find_watch(), which gives you both the wd and the watch pointer for +the inotify_watch, or an error if the watch does not exist. + + wd = inotify_find_watch(ih, inode, &watchp); + +You may use container_of() on the watch pointer to access your own data +associated with a given watch. When an existing watch is found, +inotify_find_watch() bumps the refcount before releasing its locks. You must +put that reference with: + + put_inotify_watch(watchp); + +Call inotify_find_update_watch() to update the event mask for an existing watch. +inotify_find_update_watch() returns the wd of the updated watch, or an error if +the watch does not exist. + + wd = inotify_find_update_watch(ih, inode, mask); + +An existing watch may be removed by calling either inotify_rm_watch() or +inotify_rm_wd(). + + int ret = inotify_rm_watch(ih, &my_watch->iwatch); + int ret = inotify_rm_wd(ih, wd); + +A watch may be removed while executing your event handler with the following: + + inotify_remove_watch_locked(ih, iwatch); + +Call inotify_destroy() to remove all watches from your inotify instance and +release it. If there are no outstanding references, inotify_destroy() will call +your destroy_watch op for each watch. + + inotify_destroy(ih); + +When inotify removes a watch, it sends an IN_IGNORED event to your callback. +You may use this event as an indication to free the watch memory. Note that +inotify may remove a watch due to filesystem events, as well as by your request. +If you use IN_ONESHOT, inotify will remove the watch after the first event, at +which point you may call the final inotify_put_watch. + +(iv) Kernel Interface Prototypes + + struct inotify_handle *inotify_init(struct inotify_operations *ops); + + inotify_init_watch(struct inotify_watch *watch); + + s32 inotify_add_watch(struct inotify_handle *ih, + struct inotify_watch *watch, + struct inode *inode, u32 mask); + + s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode, + struct inotify_watch **watchp); + + s32 inotify_find_update_watch(struct inotify_handle *ih, + struct inode *inode, u32 mask); + + int inotify_rm_wd(struct inotify_handle *ih, u32 wd); + + int inotify_rm_watch(struct inotify_handle *ih, + struct inotify_watch *watch); + + void inotify_remove_watch_locked(struct inotify_handle *ih, + struct inotify_watch *watch); + + void inotify_destroy(struct inotify_handle *ih); + + void get_inotify_watch(struct inotify_watch *watch); + void put_inotify_watch(struct inotify_watch *watch); + + +(v) Internal Kernel Implementation + +Each inotify instance is represented by an inotify_handle structure. +Inotify's userspace consumers also have an inotify_device which is +associated with the inotify_handle, and on which events are queued. Each watch is associated with an inotify_watch structure. Watches are chained -off of each associated device and each associated inode. +off of each associated inotify_handle and each associated inode. -See fs/inotify.c for the locking and lifetime rules. +See fs/inotify.c and fs/inotify_user.c for the locking and lifetime rules. -(iv) Rationale +(vi) Rationale Q: What is the design decision behind not tying the watch to the open fd of the watched object? @@ -145,7 +263,7 @@ A: The poor user-space interface is the second biggest problem with dnotify. file descriptor-based one that allows basic file I/O and poll/select. Obtaining the fd and managing the watches could have been done either via a device file or a family of new system calls. We decided to implement a - family of system calls because that is the preffered approach for new kernel + family of system calls because that is the preferred approach for new kernel interfaces. The only real difference was whether we wanted to use open(2) and ioctl(2) or a couple of new system calls. System calls beat ioctls. diff --git a/Documentation/infiniband/ipoib.txt b/Documentation/infiniband/ipoib.txt index 5c5a4ccce76a..187035560d7f 100644 --- a/Documentation/infiniband/ipoib.txt +++ b/Documentation/infiniband/ipoib.txt @@ -1,10 +1,10 @@ IP OVER INFINIBAND The ib_ipoib driver is an implementation of the IP over InfiniBand - protocol as specified by the latest Internet-Drafts issued by the - IETF ipoib working group. It is a "native" implementation in the - sense of setting the interface type to ARPHRD_INFINIBAND and the - hardware address length to 20 (earlier proprietary implementations + protocol as specified by RFC 4391 and 4392, issued by the IETF ipoib + working group. It is a "native" implementation in the sense of + setting the interface type to ARPHRD_INFINIBAND and the hardware + address length to 20 (earlier proprietary implementations masqueraded to the kernel as ethernet interfaces). Partitions and P_Keys @@ -53,3 +53,7 @@ References IETF IP over InfiniBand (ipoib) Working Group http://ietf.org/html.charters/ipoib-charter.html + Transmission of IP over InfiniBand (IPoIB) (RFC 4391) + http://ietf.org/rfc/rfc4391.txt + IP over InfiniBand (IPoIB) Architecture (RFC 4392) + http://ietf.org/rfc/rfc4392.txt diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b3a6187e5305..a9d3a1794b23 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1402,6 +1402,15 @@ running once the system is up. If enabled at boot time, /selinux/disable can be used later to disable prior to initial policy load. + selinux_compat_net = + [SELINUX] Set initial selinux_compat_net flag value. + Format: { "0" | "1" } + 0 -- use new secmark-based packet controls + 1 -- use legacy packet controls + Default value is 0 (preferred). + Value can be changed at runtime via + /selinux/compat_net. + serialnumber [BUGS=IA-32] sg_def_reserved_size= [SCSI] diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index c61d8b876fdb..4710845dbac4 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -19,6 +19,7 @@ Contents: - Control dependencies. - SMP barrier pairing. - Examples of memory barrier sequences. + - Read memory barriers vs load speculation. (*) Explicit kernel barriers. @@ -248,7 +249,7 @@ And there are a number of things that _must_ or _must_not_ be assumed: we may get either of: STORE *A = X; Y = LOAD *A; - STORE *A = Y; + STORE *A = Y = X; ========================= @@ -344,9 +345,12 @@ Memory barriers come in four basic varieties: (4) General memory barriers. - A general memory barrier is a combination of both a read memory barrier - and a write memory barrier. It is a partial ordering over both loads and - stores. + A general memory barrier gives a guarantee that all the LOAD and STORE + operations specified before the barrier will appear to happen before all + the LOAD and STORE operations specified after the barrier with respect to + the other components of the system. + + A general memory barrier is a partial ordering over both loads and stores. General memory barriers imply both read and write memory barriers, and so can substitute for either. @@ -546,9 +550,9 @@ write barrier, though, again, a general barrier is viable: =============== =============== a = 1; <write barrier> - b = 2; x = a; + b = 2; x = b; <read barrier> - y = b; + y = a; Or: @@ -563,6 +567,18 @@ Or: Basically, the read barrier always has to be there, even though it can be of the "weaker" type. +[!] Note that the stores before the write barrier would normally be expected to +match the loads after the read barrier or data dependency barrier, and vice +versa: + + CPU 1 CPU 2 + =============== =============== + a = 1; }---- --->{ v = c + b = 2; } \ / { w = d + <write barrier> \ <read barrier> + c = 3; } / \ { x = a; + d = 4; }---- --->{ y = b; + EXAMPLES OF MEMORY BARRIER SEQUENCES ------------------------------------ @@ -600,8 +616,8 @@ STORE B, STORE C } all occuring before the unordered set of { STORE D, STORE E | | +------+ +-------+ : : | - | Sequence in which stores committed to memory system - | by CPU 1 + | Sequence in which stores are committed to the + | memory system by CPU 1 V @@ -683,14 +699,12 @@ then the following will occur: | : : | | | : : | CPU 2 | | +-------+ | | - \ | X->9 |------>| | - \ +-------+ | | - ----->| B->2 | | | - +-------+ | | - Makes sure all effects ---> ddddddddddddddddd | | - prior to the store of C +-------+ | | - are perceptible to | B->2 |------>| | - successive loads +-------+ | | + | | X->9 |------>| | + | +-------+ | | + Makes sure all effects ---> \ ddddddddddddddddd | | + prior to the store of C \ +-------+ | | + are perceptible to ----->| B->2 |------>| | + subsequent loads +-------+ | | : : +-------+ @@ -699,73 +713,239 @@ following sequence of events: CPU 1 CPU 2 ======================= ======================= + { A = 0, B = 9 } STORE A=1 - STORE B=2 - STORE C=3 <write barrier> - STORE D=4 - STORE E=5 - LOAD A + STORE B=2 LOAD B - LOAD C - LOAD D - LOAD E + LOAD A Without intervention, CPU 2 may then choose to perceive the events on CPU 1 in some effectively random order, despite the write barrier issued by CPU 1: - +-------+ : : - | | +------+ - | |------>| C=3 | } - | | : +------+ } - | | : | A=1 | } - | | : +------+ } - | CPU 1 | : | B=2 | }--- - | | +------+ } \ - | | wwwwwwwwwwwww} \ - | | +------+ } \ : : +-------+ - | | : | E=5 | } \ +-------+ | | - | | : +------+ } \ { | C->3 |------>| | - | |------>| D=4 | } \ { +-------+ : | | - | | +------+ \ { | E->5 | : | | - +-------+ : : \ { +-------+ : | | - Transfer -->{ | A->1 | : | CPU 2 | - from CPU 1 { +-------+ : | | - to CPU 2 { | D->4 | : | | - { +-------+ : | | - { | B->2 |------>| | - +-------+ | | - : : +-------+ - - -If, however, a read barrier were to be placed between the load of C and the -load of D on CPU 2, then the partial ordering imposed by CPU 1 will be -perceived correctly by CPU 2. + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | | A->0 |------>| | + | +-------+ | | + | : : +-------+ + \ : : + \ +-------+ + ---->| A->1 | + +-------+ + : : - +-------+ : : - | | +------+ - | |------>| C=3 | } - | | : +------+ } - | | : | A=1 | }--- - | | : +------+ } \ - | CPU 1 | : | B=2 | } \ - | | +------+ \ - | | wwwwwwwwwwwwwwww \ - | | +------+ \ : : +-------+ - | | : | E=5 | } \ +-------+ | | - | | : +------+ }--- \ { | C->3 |------>| | - | |------>| D=4 | } \ \ { +-------+ : | | - | | +------+ \ -->{ | B->2 | : | | - +-------+ : : \ { +-------+ : | | - \ { | A->1 | : | CPU 2 | - \ +-------+ | | - At this point the read ----> \ rrrrrrrrrrrrrrrrr | | - barrier causes all effects \ +-------+ | | - prior to the storage of C \ { | E->5 | : | | - to be perceptible to CPU 2 -->{ +-------+ : | | - { | D->4 |------>| | - +-------+ | | - : : +-------+ + +If, however, a read barrier were to be placed between the load of E and the +load of A on CPU 2: + + CPU 1 CPU 2 + ======================= ======================= + { A = 0, B = 9 } + STORE A=1 + <write barrier> + STORE B=2 + LOAD B + <read barrier> + LOAD A + +then the partial ordering imposed by CPU 1 will be perceived correctly by CPU +2: + + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | : : | | + | : : | | + At this point the read ----> \ rrrrrrrrrrrrrrrrr | | + barrier causes all effects \ +-------+ | | + prior to the storage of B ---->| A->1 |------>| | + to be perceptible to CPU 2 +-------+ | | + : : +-------+ + + +To illustrate this more completely, consider what could happen if the code +contained a load of A either side of the read barrier: + + CPU 1 CPU 2 + ======================= ======================= + { A = 0, B = 9 } + STORE A=1 + <write barrier> + STORE B=2 + LOAD B + LOAD A [first load of A] + <read barrier> + LOAD A [second load of A] + +Even though the two loads of A both occur after the load of B, they may both +come up with different values: + + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | : : | | + | : : | | + | +-------+ | | + | | A->0 |------>| 1st | + | +-------+ | | + At this point the read ----> \ rrrrrrrrrrrrrrrrr | | + barrier causes all effects \ +-------+ | | + prior to the storage of B ---->| A->1 |------>| 2nd | + to be perceptible to CPU 2 +-------+ | | + : : +-------+ + + +But it may be that the update to A from CPU 1 becomes perceptible to CPU 2 +before the read barrier completes anyway: + + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | : : | | + \ : : | | + \ +-------+ | | + ---->| A->1 |------>| 1st | + +-------+ | | + rrrrrrrrrrrrrrrrr | | + +-------+ | | + | A->1 |------>| 2nd | + +-------+ | | + : : +-------+ + + +The guarantee is that the second load will always come up with A == 1 if the +load of B came up with B == 2. No such guarantee exists for the first load of +A; that may come up with either A == 0 or A == 1. + + +READ MEMORY BARRIERS VS LOAD SPECULATION +---------------------------------------- + +Many CPUs speculate with loads: that is they see that they will need to load an +item from memory, and they find a time where they're not using the bus for any +other loads, and so do the load in advance - even though they haven't actually +got to that point in the instruction execution flow yet. This permits the +actual load instruction to potentially complete immediately because the CPU +already has the value to hand. + +It may turn out that the CPU didn't actually need the value - perhaps because a +branch circumvented the load - in which case it can discard the value or just +cache it for later use. + +Consider: + + CPU 1 CPU 2 + ======================= ======================= + LOAD B + DIVIDE } Divide instructions generally + DIVIDE } take a long time to perform + LOAD A + +Which might appear as this: + + : : +-------+ + +-------+ | | + --->| B->2 |------>| | + +-------+ | CPU 2 | + : :DIVIDE | | + +-------+ | | + The CPU being busy doing a ---> --->| A->0 |~~~~ | | + division speculates on the +-------+ ~ | | + LOAD of A : : ~ | | + : :DIVIDE | | + : : ~ | | + Once the divisions are complete --> : : ~-->| | + the CPU can then perform the : : | | + LOAD with immediate effect : : +-------+ + + +Placing a read barrier or a data dependency barrier just before the second +load: + + CPU 1 CPU 2 + ======================= ======================= + LOAD B + DIVIDE + DIVIDE + <read barrier> + LOAD A + +will force any value speculatively obtained to be reconsidered to an extent +dependent on the type of barrier used. If there was no change made to the +speculated memory location, then the speculated value will just be used: + + : : +-------+ + +-------+ | | + --->| B->2 |------>| | + +-------+ | CPU 2 | + : :DIVIDE | | + +-------+ | | + The CPU being busy doing a ---> --->| A->0 |~~~~ | | + division speculates on the +-------+ ~ | | + LOAD of A : : ~ | | + : :DIVIDE | | + : : ~ | | + : : ~ | | + rrrrrrrrrrrrrrrr~ | | + : : ~ | | + : : ~-->| | + : : | | + : : +-------+ + + +but if there was an update or an invalidation from another CPU pending, then +the speculation will be cancelled and the value reloaded: + + : : +-------+ + +-------+ | | + --->| B->2 |------>| | + +-------+ | CPU 2 | + : :DIVIDE | | + +-------+ | | + The CPU being busy doing a ---> --->| A->0 |~~~~ | | + division speculates on the +-------+ ~ | | + LOAD of A : : ~ | | + : :DIVIDE | | + : : ~ | | + : : ~ | | + rrrrrrrrrrrrrrrrr | | + +-------+ | | + The speculation is discarded ---> --->| A->1 |------>| | + and an updated value is +-------+ | | + retrieved : : +-------+ ======================== @@ -901,7 +1081,7 @@ IMPLICIT KERNEL MEMORY BARRIERS =============================== Some of the other functions in the linux kernel imply memory barriers, amongst -which are locking, scheduling and memory allocation functions. +which are locking and scheduling functions. This specification is a _minimum_ guarantee; any particular architecture may provide more substantial guarantees, but these may not be relied upon outside @@ -966,6 +1146,20 @@ equivalent to a full barrier, but a LOCK followed by an UNLOCK is not. barriers is that the effects instructions outside of a critical section may seep into the inside of the critical section. +A LOCK followed by an UNLOCK may not be assumed to be full memory barrier +because it is possible for an access preceding the LOCK to happen after the +LOCK, and an access following the UNLOCK to happen before the UNLOCK, and the +two accesses can themselves then cross: + + *A = a; + LOCK + UNLOCK + *B = b; + +may occur as: + + LOCK, STORE *B, STORE *A, UNLOCK + Locks and semaphores may not provide any guarantee of ordering on UP compiled systems, and so cannot be counted on in such a situation to actually achieve anything at all - especially with respect to I/O accesses - unless combined @@ -1016,8 +1210,6 @@ Other functions that imply barriers: (*) schedule() and similar imply full memory barriers. - (*) Memory allocation and release functions imply full memory barriers. - ================================= INTER-CPU LOCKING BARRIER EFFECTS diff --git a/Documentation/networking/README.ipw2200 b/Documentation/networking/README.ipw2200 index acb30c5dcff3..4f2a40f1dbc6 100644 --- a/Documentation/networking/README.ipw2200 +++ b/Documentation/networking/README.ipw2200 @@ -14,8 +14,8 @@ Copyright (C) 2004-2006, Intel Corporation README.ipw2200 -Version: 1.0.8 -Date : October 20, 2005 +Version: 1.1.2 +Date : March 30, 2006 Index @@ -103,7 +103,7 @@ file. 1.1. Overview of Features ----------------------------------------------- -The current release (1.0.8) supports the following features: +The current release (1.1.2) supports the following features: + BSS mode (Infrastructure, Managed) + IBSS mode (Ad-Hoc) @@ -247,8 +247,8 @@ and can set the contents via echo. For example: % cat /sys/bus/pci/drivers/ipw2200/debug_level Will report the current debug level of the driver's logging subsystem -(only available if CONFIG_IPW_DEBUG was configured when the driver was -built). +(only available if CONFIG_IPW2200_DEBUG was configured when the driver +was built). You can set the debug level via: diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 8d8b4e5ea184..afac780445cd 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -1,7 +1,7 @@ Linux Ethernet Bonding Driver HOWTO - Latest update: 21 June 2005 + Latest update: 24 April 2006 Initial release : Thomas Davis <tadavis at lbl.gov> Corrections, HA extensions : 2000/10/03-15 : @@ -12,6 +12,8 @@ Corrections, HA extensions : 2000/10/03-15 : - Jay Vosburgh <fubar at us dot ibm dot com> Reorganized and updated Feb 2005 by Jay Vosburgh +Added Sysfs information: 2006/04/24 + - Mitch Williams <mitch.a.williams at intel.com> Introduction ============ @@ -38,61 +40,62 @@ Table of Contents 2. Bonding Driver Options 3. Configuring Bonding Devices -3.1 Configuration with sysconfig support -3.1.1 Using DHCP with sysconfig -3.1.2 Configuring Multiple Bonds with sysconfig -3.2 Configuration with initscripts support -3.2.1 Using DHCP with initscripts -3.2.2 Configuring Multiple Bonds with initscripts -3.3 Configuring Bonding Manually +3.1 Configuration with Sysconfig Support +3.1.1 Using DHCP with Sysconfig +3.1.2 Configuring Multiple Bonds with Sysconfig +3.2 Configuration with Initscripts Support +3.2.1 Using DHCP with Initscripts +3.2.2 Configuring Multiple Bonds with Initscripts +3.3 Configuring Bonding Manually with Ifenslave 3.3.1 Configuring Multiple Bonds Manually +3.4 Configuring Bonding Manually via Sysfs -5. Querying Bonding Configuration -5.1 Bonding Configuration -5.2 Network Configuration +4. Querying Bonding Configuration +4.1 Bonding Configuration +4.2 Network Configuration -6. Switch Configuration +5. Switch Configuration -7. 802.1q VLAN Support +6. 802.1q VLAN Support -8. Link Monitoring -8.1 ARP Monitor Operation -8.2 Configuring Multiple ARP Targets -8.3 MII Monitor Operation +7. Link Monitoring +7.1 ARP Monitor Operation +7.2 Configuring Multiple ARP Targets +7.3 MII Monitor Operation -9. Potential Trouble Sources -9.1 Adventures in Routing -9.2 Ethernet Device Renaming -9.3 Painfully Slow Or No Failed Link Detection By Miimon +8. Potential Trouble Sources +8.1 Adventures in Routing +8.2 Ethernet Device Renaming +8.3 Painfully Slow Or No Failed Link Detection By Miimon -10. SNMP agents +9. SNMP agents -11. Promiscuous mode +10. Promiscuous mode -12. Configuring Bonding for High Availability -12.1 High Availability in a Single Switch Topology -12.2 High Availability in a Multiple Switch Topology -12.2.1 HA Bonding Mode Selection for Multiple Switch Topology -12.2.2 HA Link Monitoring for Multiple Switch Topology +11. Configuring Bonding for High Availability +11.1 High Availability in a Single Switch Topology +11.2 High Availability in a Multiple Switch Topology +11.2.1 HA Bonding Mode Selection for Multiple Switch Topology +11.2.2 HA Link Monitoring for Multiple Switch Topology -13. Configuring Bonding for Maximum Throughput -13.1 Maximum Throughput in a Single Switch Topology -13.1.1 MT Bonding Mode Selection for Single Switch Topology -13.1.2 MT Link Monitoring for Single Switch Topology -13.2 Maximum Throughput in a Multiple Switch Topology -13.2.1 MT Bonding Mode Selection for Multiple Switch Topology -13.2.2 MT Link Monitoring for Multiple Switch Topology +12. Configuring Bonding for Maximum Throughput +12.1 Maximum Throughput in a Single Switch Topology +12.1.1 MT Bonding Mode Selection for Single Switch Topology +12.1.2 MT Link Monitoring for Single Switch Topology +12.2 Maximum Throughput in a Multiple Switch Topology +12.2.1 MT Bonding Mode Selection for Multiple Switch Topology +12.2.2 MT Link Monitoring for Multiple Switch Topology -14. Switch Behavior Issues -14.1 Link Establishment and Failover Delays -14.2 Duplicated Incoming Packets +13. Switch Behavior Issues +13.1 Link Establishment and Failover Delays +13.2 Duplicated Incoming Packets -15. Hardware Specific Considerations -15.1 IBM BladeCenter +14. Hardware Specific Considerations +14.1 IBM BladeCenter -16. Frequently Asked Questions +15. Frequently Asked Questions -17. Resources and Links +16. Resources and Links 1. Bonding Driver Installation @@ -156,6 +159,9 @@ you're trying to build it for. Some distros (e.g., Red Hat from 7.1 onwards) do not have /usr/include/linux symbolically linked to the default kernel source include directory. +SECOND IMPORTANT NOTE: + If you plan to configure bonding using sysfs, you do not need +to use ifenslave. 2. Bonding Driver Options ========================= @@ -270,7 +276,7 @@ mode In bonding version 2.6.2 or later, when a failover occurs in active-backup mode, bonding will issue one or more gratuitous ARPs on the newly active slave. - One gratutious ARP is issued for the bonding master + One gratuitous ARP is issued for the bonding master interface and each VLAN interfaces configured above it, provided that the interface has at least one IP address configured. Gratuitous ARPs issued for VLAN @@ -377,7 +383,7 @@ mode When a link is reconnected or a new slave joins the bond the receive traffic is redistributed among all active slaves in the bond by initiating ARP Replies - with the selected mac address to each of the + with the selected MAC address to each of the clients. The updelay parameter (detailed below) must be set to a value equal or greater than the switch's forwarding delay so that the ARP Replies sent to the @@ -498,11 +504,12 @@ not exist, and the layer2 policy is the only policy. 3. Configuring Bonding Devices ============================== - There are, essentially, two methods for configuring bonding: -with support from the distro's network initialization scripts, and -without. Distros generally use one of two packages for the network -initialization scripts: initscripts or sysconfig. Recent versions of -these packages have support for bonding, while older versions do not. + You can configure bonding using either your distro's network +initialization scripts, or manually using either ifenslave or the +sysfs interface. Distros generally use one of two packages for the +network initialization scripts: initscripts or sysconfig. Recent +versions of these packages have support for bonding, while older +versions do not. We will first describe the options for configuring bonding for distros using versions of initscripts and sysconfig with full or @@ -530,7 +537,7 @@ $ grep ifenslave /sbin/ifup If this returns any matches, then your initscripts or sysconfig has support for bonding. -3.1 Configuration with sysconfig support +3.1 Configuration with Sysconfig Support ---------------------------------------- This section applies to distros using a version of sysconfig @@ -538,7 +545,7 @@ with bonding support, for example, SuSE Linux Enterprise Server 9. SuSE SLES 9's networking configuration system does support bonding, however, at this writing, the YaST system configuration -frontend does not provide any means to work with bonding devices. +front end does not provide any means to work with bonding devices. Bonding devices can be managed by hand, however, as follows. First, if they have not already been configured, configure the @@ -660,7 +667,7 @@ format can be found in an example ifcfg template file: Note that the template does not document the various BONDING_ settings described above, but does describe many of the other options. -3.1.1 Using DHCP with sysconfig +3.1.1 Using DHCP with Sysconfig ------------------------------- Under sysconfig, configuring a device with BOOTPROTO='dhcp' @@ -670,7 +677,7 @@ attempt to obtain the device address from DHCP prior to adding any of the slave devices. Without active slaves, the DHCP requests are not sent to the network. -3.1.2 Configuring Multiple Bonds with sysconfig +3.1.2 Configuring Multiple Bonds with Sysconfig ----------------------------------------------- The sysconfig network initialization system is capable of @@ -685,7 +692,7 @@ ifcfg-bondX files. options in the ifcfg-bondX file, it is not necessary to add them to the system /etc/modules.conf or /etc/modprobe.conf configuration file. -3.2 Configuration with initscripts support +3.2 Configuration with Initscripts Support ------------------------------------------ This section applies to distros using a version of initscripts @@ -756,7 +763,7 @@ options for your configuration. will restart the networking subsystem and your bond link should be now up and running. -3.2.1 Using DHCP with initscripts +3.2.1 Using DHCP with Initscripts --------------------------------- Recent versions of initscripts (the version supplied with @@ -768,7 +775,7 @@ above, except replace the line "BOOTPROTO=none" with "BOOTPROTO=dhcp" and add a line consisting of "TYPE=Bonding". Note that the TYPE value is case sensitive. -3.2.2 Configuring Multiple Bonds with initscripts +3.2.2 Configuring Multiple Bonds with Initscripts ------------------------------------------------- At this writing, the initscripts package does not directly @@ -784,8 +791,8 @@ Fedora Core kernels, and has been seen on RHEL 4 as well. On kernels exhibiting this problem, it will be impossible to configure multiple bonds with differing parameters. -3.3 Configuring Bonding Manually --------------------------------- +3.3 Configuring Bonding Manually with Ifenslave +----------------------------------------------- This section applies to distros whose network initialization scripts (the sysconfig or initscripts package) do not have specific @@ -889,11 +896,139 @@ install bond1 /sbin/modprobe --ignore-install bonding -o bond1 \ This may be repeated any number of times, specifying a new and unique name in place of bond1 for each subsequent instance. +3.4 Configuring Bonding Manually via Sysfs +------------------------------------------ + + Starting with version 3.0, Channel Bonding may be configured +via the sysfs interface. This interface allows dynamic configuration +of all bonds in the system without unloading the module. It also +allows for adding and removing bonds at runtime. Ifenslave is no +longer required, though it is still supported. + + Use of the sysfs interface allows you to use multiple bonds +with different configurations without having to reload the module. +It also allows you to use multiple, differently configured bonds when +bonding is compiled into the kernel. + + You must have the sysfs filesystem mounted to configure +bonding this way. The examples in this document assume that you +are using the standard mount point for sysfs, e.g. /sys. If your +sysfs filesystem is mounted elsewhere, you will need to adjust the +example paths accordingly. + +Creating and Destroying Bonds +----------------------------- +To add a new bond foo: +# echo +foo > /sys/class/net/bonding_masters + +To remove an existing bond bar: +# echo -bar > /sys/class/net/bonding_masters + +To show all existing bonds: +# cat /sys/class/net/bonding_masters + +NOTE: due to 4K size limitation of sysfs files, this list may be +truncated if you have more than a few hundred bonds. This is unlikely +to occur under normal operating conditions. + +Adding and Removing Slaves +-------------------------- + Interfaces may be enslaved to a bond using the file +/sys/class/net/<bond>/bonding/slaves. The semantics for this file +are the same as for the bonding_masters file. + +To enslave interface eth0 to bond bond0: +# ifconfig bond0 up +# echo +eth0 > /sys/class/net/bond0/bonding/slaves + +To free slave eth0 from bond bond0: +# echo -eth0 > /sys/class/net/bond0/bonding/slaves + + NOTE: The bond must be up before slaves can be added. All +slaves are freed when the interface is brought down. + + When an interface is enslaved to a bond, symlinks between the +two are created in the sysfs filesystem. In this case, you would get +/sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and +/sys/class/net/eth0/master pointing to /sys/class/net/bond0. + + This means that you can tell quickly whether or not an +interface is enslaved by looking for the master symlink. Thus: +# echo -eth0 > /sys/class/net/eth0/master/bonding/slaves +will free eth0 from whatever bond it is enslaved to, regardless of +the name of the bond interface. + +Changing a Bond's Configuration +------------------------------- + Each bond may be configured individually by manipulating the +files located in /sys/class/net/<bond name>/bonding + + The names of these files correspond directly with the command- +line parameters described elsewhere in in this file, and, with the +exception of arp_ip_target, they accept the same values. To see the +current setting, simply cat the appropriate file. + + A few examples will be given here; for specific usage +guidelines for each parameter, see the appropriate section in this +document. + +To configure bond0 for balance-alb mode: +# ifconfig bond0 down +# echo 6 > /sys/class/net/bond0/bonding/mode + - or - +# echo balance-alb > /sys/class/net/bond0/bonding/mode + NOTE: The bond interface must be down before the mode can be +changed. + +To enable MII monitoring on bond0 with a 1 second interval: +# echo 1000 > /sys/class/net/bond0/bonding/miimon + NOTE: If ARP monitoring is enabled, it will disabled when MII +monitoring is enabled, and vice-versa. + +To add ARP targets: +# echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target +# echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target + NOTE: up to 10 target addresses may be specified. + +To remove an ARP target: +# echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target + +Example Configuration +--------------------- + We begin with the same example that is shown in section 3.3, +executed with sysfs, and without using ifenslave. + + To make a simple bond of two e100 devices (presumed to be eth0 +and eth1), and have it persist across reboots, edit the appropriate +file (/etc/init.d/boot.local or /etc/rc.d/rc.local), and add the +following: + +modprobe bonding +modprobe e100 +echo balance-alb > /sys/class/net/bond0/bonding/mode +ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up +echo 100 > /sys/class/net/bond0/bonding/miimon +echo +eth0 > /sys/class/net/bond0/bonding/slaves +echo +eth1 > /sys/class/net/bond0/bonding/slaves + + To add a second bond, with two e1000 interfaces in +active-backup mode, using ARP monitoring, add the following lines to +your init script: + +modprobe e1000 +echo +bond1 > /sys/class/net/bonding_masters +echo active-backup > /sys/class/net/bond1/bonding/mode +ifconfig bond1 192.168.2.1 netmask 255.255.255.0 up +echo +192.168.2.100 /sys/class/net/bond1/bonding/arp_ip_target +echo 2000 > /sys/class/net/bond1/bonding/arp_interval +echo +eth2 > /sys/class/net/bond1/bonding/slaves +echo +eth3 > /sys/class/net/bond1/bonding/slaves + -5. Querying Bonding Configuration +4. Querying Bonding Configuration ================================= -5.1 Bonding Configuration +4.1 Bonding Configuration ------------------------- Each bonding device has a read-only file residing in the @@ -923,7 +1058,7 @@ generally as follows: The precise format and contents will change depending upon the bonding configuration, state, and version of the bonding driver. -5.2 Network configuration +4.2 Network configuration ------------------------- The network configuration can be inspected using the ifconfig @@ -958,7 +1093,7 @@ eth1 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 collisions:0 txqueuelen:100 Interrupt:9 Base address:0x1400 -6. Switch Configuration +5. Switch Configuration ======================= For this section, "switch" refers to whatever system the @@ -991,7 +1126,7 @@ transmit policy for an EtherChannel group; all three will interoperate with another EtherChannel group. -7. 802.1q VLAN Support +6. 802.1q VLAN Support ====================== It is possible to configure VLAN devices over a bond interface @@ -1042,7 +1177,7 @@ underlying device -- i.e. the bonding interface -- to promiscuous mode, which might not be what you want. -8. Link Monitoring +7. Link Monitoring ================== The bonding driver at present supports two schemes for @@ -1053,7 +1188,7 @@ monitor. bonding driver itself, it is not possible to enable both ARP and MII monitoring simultaneously. -8.1 ARP Monitor Operation +7.1 ARP Monitor Operation ------------------------- The ARP monitor operates as its name suggests: it sends ARP @@ -1071,7 +1206,7 @@ those slaves will stay down. If networking monitoring (tcpdump, etc) shows the ARP requests and replies on the network, then it may be that your device driver is not updating last_rx and trans_start. -8.2 Configuring Multiple ARP Targets +7.2 Configuring Multiple ARP Targets ------------------------------------ While ARP monitoring can be done with just one target, it can @@ -1094,7 +1229,7 @@ alias bond0 bonding options bond0 arp_interval=60 arp_ip_target=192.168.0.100 -8.3 MII Monitor Operation +7.3 MII Monitor Operation ------------------------- The MII monitor monitors only the carrier state of the local @@ -1120,14 +1255,14 @@ does not support or had some error in processing both the MII register and ethtool requests), then the MII monitor will assume the link is up. -9. Potential Sources of Trouble +8. Potential Sources of Trouble =============================== -9.1 Adventures in Routing +8.1 Adventures in Routing ------------------------- When bonding is configured, it is important that the slave -devices not have routes that supercede routes of the master (or, +devices not have routes that supersede routes of the master (or, generally, not have routes at all). For example, suppose the bonding device bond0 has two slaves, eth0 and eth1, and the routing table is as follows: @@ -1154,11 +1289,11 @@ by the state of the routing table. The solution here is simply to insure that slaves do not have routes of their own, and if for some reason they must, those routes do -not supercede routes of their master. This should generally be the +not supersede routes of their master. This should generally be the case, but unusual configurations or errant manual or automatic static route additions may cause trouble. -9.2 Ethernet Device Renaming +8.2 Ethernet Device Renaming ---------------------------- On systems with network configuration scripts that do not @@ -1207,7 +1342,7 @@ modprobe with --ignore-install to cause the normal action to then take place. Full documentation on this can be found in the modprobe.conf and modprobe manual pages. -9.3. Painfully Slow Or No Failed Link Detection By Miimon +8.3. Painfully Slow Or No Failed Link Detection By Miimon --------------------------------------------------------- By default, bonding enables the use_carrier option, which @@ -1235,7 +1370,7 @@ carrier state. It has no way to determine the state of devices on or beyond other ports of a switch, or if a switch is refusing to pass traffic while still maintaining carrier on. -10. SNMP agents +9. SNMP agents =============== If running SNMP agents, the bonding driver should be loaded @@ -1281,7 +1416,7 @@ ifDescr, the association between the IP address and IfIndex remains and SNMP functions such as Interface_Scan_Next will report that association. -11. Promiscuous mode +10. Promiscuous mode ==================== When running network monitoring tools, e.g., tcpdump, it is @@ -1308,7 +1443,7 @@ sending to peers that are unassigned or if the load is unbalanced. the active slave changes (e.g., due to a link failure), the promiscuous setting will be propagated to the new active slave. -12. Configuring Bonding for High Availability +11. Configuring Bonding for High Availability ============================================= High Availability refers to configurations that provide @@ -1318,7 +1453,7 @@ goal is to provide the maximum availability of network connectivity (i.e., the network always works), even though other configurations could provide higher throughput. -12.1 High Availability in a Single Switch Topology +11.1 High Availability in a Single Switch Topology -------------------------------------------------- If two hosts (or a host and a single switch) are directly @@ -1332,7 +1467,7 @@ the load will be rebalanced across the remaining devices. See Section 13, "Configuring Bonding for Maximum Throughput" for information on configuring bonding with one peer device. -12.2 High Availability in a Multiple Switch Topology +11.2 High Availability in a Multiple Switch Topology ---------------------------------------------------- With multiple switches, the configuration of bonding and the @@ -1359,7 +1494,7 @@ switches (ISL, or inter switch link), and multiple ports connecting to the outside world ("port3" on each switch). There is no technical reason that this could not be extended to a third switch. -12.2.1 HA Bonding Mode Selection for Multiple Switch Topology +11.2.1 HA Bonding Mode Selection for Multiple Switch Topology ------------------------------------------------------------- In a topology such as the example above, the active-backup and @@ -1381,7 +1516,7 @@ broadcast: This mode is really a special purpose mode, and is suitable necessary for some specific one-way traffic to reach both independent networks, then the broadcast mode may be suitable. -12.2.2 HA Link Monitoring Selection for Multiple Switch Topology +11.2.2 HA Link Monitoring Selection for Multiple Switch Topology ---------------------------------------------------------------- The choice of link monitoring ultimately depends upon your @@ -1402,10 +1537,10 @@ regardless of which switch is active, the ARP monitor has a suitable target to query. -13. Configuring Bonding for Maximum Throughput +12. Configuring Bonding for Maximum Throughput ============================================== -13.1 Maximizing Throughput in a Single Switch Topology +12.1 Maximizing Throughput in a Single Switch Topology ------------------------------------------------------ In a single switch configuration, the best method to maximize @@ -1476,7 +1611,7 @@ destination to make load balancing decisions. The behavior of each mode is described below. -13.1.1 MT Bonding Mode Selection for Single Switch Topology +12.1.1 MT Bonding Mode Selection for Single Switch Topology ----------------------------------------------------------- This configuration is the easiest to set up and to understand, @@ -1607,7 +1742,7 @@ balance-alb: This mode is everything that balance-tlb is, and more. device driver must support changing the hardware address while the device is open. -13.1.2 MT Link Monitoring for Single Switch Topology +12.1.2 MT Link Monitoring for Single Switch Topology ---------------------------------------------------- The choice of link monitoring may largely depend upon which @@ -1616,7 +1751,7 @@ support the use of the ARP monitor, and are thus restricted to using the MII monitor (which does not provide as high a level of end to end assurance as the ARP monitor). -13.2 Maximum Throughput in a Multiple Switch Topology +12.2 Maximum Throughput in a Multiple Switch Topology ----------------------------------------------------- Multiple switches may be utilized to optimize for throughput @@ -1651,7 +1786,7 @@ a single 72 port switch. can be equipped with an additional network device connected to an external network; this host then additionally acts as a gateway. -13.2.1 MT Bonding Mode Selection for Multiple Switch Topology +12.2.1 MT Bonding Mode Selection for Multiple Switch Topology ------------------------------------------------------------- In actual practice, the bonding mode typically employed in @@ -1664,7 +1799,7 @@ packets has arrived). When employed in this fashion, the balance-rr mode allows individual connections between two hosts to effectively utilize greater than one interface's bandwidth. -13.2.2 MT Link Monitoring for Multiple Switch Topology +12.2.2 MT Link Monitoring for Multiple Switch Topology ------------------------------------------------------ Again, in actual practice, the MII monitor is most often used @@ -1674,10 +1809,10 @@ advantages over the MII monitor are mitigated by the volume of probes needed as the number of systems involved grows (remember that each host in the network is configured with bonding). -14. Switch Behavior Issues +13. Switch Behavior Issues ========================== -14.1 Link Establishment and Failover Delays +13.1 Link Establishment and Failover Delays ------------------------------------------- Some switches exhibit undesirable behavior with regard to the @@ -1712,7 +1847,7 @@ switches take a long time to go into backup mode, it may be desirable to not activate a backup interface immediately after a link goes down. Failover may be delayed via the downdelay bonding module option. -14.2 Duplicated Incoming Packets +13.2 Duplicated Incoming Packets -------------------------------- It is not uncommon to observe a short burst of duplicated @@ -1751,14 +1886,14 @@ behavior, it can be induced by clearing the MAC forwarding table (on most Cisco switches, the privileged command "clear mac address-table dynamic" will accomplish this). -15. Hardware Specific Considerations +14. Hardware Specific Considerations ==================================== This section contains additional information for configuring bonding on specific hardware platforms, or for interfacing bonding with particular switches or other devices. -15.1 IBM BladeCenter +14.1 IBM BladeCenter -------------------- This applies to the JS20 and similar systems. @@ -1861,7 +1996,7 @@ bonding driver. avoid fail-over delay issues when using bonding. -16. Frequently Asked Questions +15. Frequently Asked Questions ============================== 1. Is it SMP safe? @@ -1925,7 +2060,7 @@ not have special switch requirements, but do need device drivers that support specific features (described in the appropriate section under module parameters, above). - In 802.3ad mode, it works with with systems that support IEEE + In 802.3ad mode, it works with systems that support IEEE 802.3ad Dynamic Link Aggregation. Most managed and many unmanaged switches currently available support 802.3ad. diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index f12007b80a46..d46338af6002 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -362,6 +362,13 @@ tcp_workaround_signed_windows - BOOLEAN not receive a window scaling option from them. Default: 0 +tcp_slow_start_after_idle - BOOLEAN + If set, provide RFC2861 behavior and time out the congestion + window after an idle period. An idle period is defined at + the current RTO. If unset, the congestion window will not + be timed out after an idle period. + Default: 1 + IP Variables: ip_local_port_range - 2 INTEGERS diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt index 3c0a5ba614d7..847cedb238f6 100644 --- a/Documentation/networking/netdevices.txt +++ b/Documentation/networking/netdevices.txt @@ -42,9 +42,9 @@ dev->get_stats: Context: nominally process, but don't sleep inside an rwlock dev->hard_start_xmit: - Synchronization: dev->xmit_lock spinlock. + Synchronization: netif_tx_lock spinlock. When the driver sets NETIF_F_LLTX in dev->features this will be - called without holding xmit_lock. In this case the driver + called without holding netif_tx_lock. In this case the driver has to lock by itself when needed. It is recommended to use a try lock for this and return -1 when the spin lock fails. The locking there should also properly protect against @@ -62,12 +62,12 @@ dev->hard_start_xmit: Only valid when NETIF_F_LLTX is set. dev->tx_timeout: - Synchronization: dev->xmit_lock spinlock. + Synchronization: netif_tx_lock spinlock. Context: BHs disabled Notes: netif_queue_stopped() is guaranteed true dev->set_multicast_list: - Synchronization: dev->xmit_lock spinlock. + Synchronization: netif_tx_lock spinlock. Context: BHs disabled dev->poll: |