---

yaml
---
r: 190251
b: refs/heads/master
c: 202f2bb
h: refs/heads/master
i:
  190249: 350c9e5
  190247: 3cc8e73
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b90f687018e6d6c77d981b09203780f7001407e5
+refs/heads/master: 202f2bb0708e968099a23fead4598a4c3f8f8637

trunk/Documentation/DocBook/tracepoint.tmpl

@@ -16,6 +16,15 @@
      </address>
     </affiliation>
    </author>
+   <author>
+    <firstname>William</firstname>
+    <surname>Cohen</surname>
+    <affiliation>
+     <address>
+      <email>wcohen@redhat.com</email>
+     </address>
+    </affiliation>
+   </author>
   </authorgroup>
 
   <legalnotice>
@@ -91,4 +100,8 @@
 !Iinclude/trace/events/signal.h
   </chapter>
 
+  <chapter id="block">
+   <title>Block IO</title>
+!Iinclude/trace/events/block.h
+  </chapter>
 </book>

trunk/Documentation/HOWTO

@@ -234,7 +234,7 @@ process is as follows:
     Linus, usually the patches that have already been included in the
     -next kernel for a few weeks.  The preferred way to submit big changes
     is using git (the kernel's source management tool, more information
-    can be found at http://git.or.cz/) but plain patches are also just
+    can be found at http://git-scm.com/) but plain patches are also just
     fine.
   - After two weeks a -rc1 kernel is released it is now possible to push
     only patches that do not include new features that could affect the

trunk/Documentation/RCU/NMI-RCU.txt

@@ -34,7 +34,7 @@ NMI handler.
 		cpu = smp_processor_id();
 		++nmi_count(cpu);
 
-		if (!rcu_dereference(nmi_callback)(regs, cpu))
+		if (!rcu_dereference_sched(nmi_callback)(regs, cpu))
 			default_do_nmi(regs);
 
 		nmi_exit();
@@ -47,12 +47,13 @@ function pointer.  If this handler returns zero, do_nmi() invokes the
 default_do_nmi() function to handle a machine-specific NMI.  Finally,
 preemption is restored.
 
-Strictly speaking, rcu_dereference() is not needed, since this code runs
-only on i386, which does not need rcu_dereference() anyway.  However,
-it is a good documentation aid, particularly for anyone attempting to
-do something similar on Alpha.
+In theory, rcu_dereference_sched() is not needed, since this code runs
+only on i386, which in theory does not need rcu_dereference_sched()
+anyway.  However, in practice it is a good documentation aid, particularly
+for anyone attempting to do something similar on Alpha or on systems
+with aggressive optimizing compilers.
 
-Quick Quiz:  Why might the rcu_dereference() be necessary on Alpha,
+Quick Quiz:  Why might the rcu_dereference_sched() be necessary on Alpha,
 	     given that the code referenced by the pointer is read-only?
 
 
@@ -99,17 +100,21 @@ invoke irq_enter() and irq_exit() on NMI entry and exit, respectively.
 
 Answer to Quick Quiz
 
-	Why might the rcu_dereference() be necessary on Alpha, given
+	Why might the rcu_dereference_sched() be necessary on Alpha, given
 	that the code referenced by the pointer is read-only?
 
 	Answer: The caller to set_nmi_callback() might well have
-		initialized some data that is to be used by the
-		new NMI handler.  In this case, the rcu_dereference()
-		would be needed, because otherwise a CPU that received
-		an NMI just after the new handler was set might see
-		the pointer to the new NMI handler, but the old
-		pre-initialized version of the handler's data.
-
-		More important, the rcu_dereference() makes it clear
-		to someone reading the code that the pointer is being
-		protected by RCU.
+		initialized some data that is to be used by the new NMI
+		handler.  In this case, the rcu_dereference_sched() would
+		be needed, because otherwise a CPU that received an NMI
+		just after the new handler was set might see the pointer
+		to the new NMI handler, but the old pre-initialized
+		version of the handler's data.
+
+		This same sad story can happen on other CPUs when using
+		a compiler with aggressive pointer-value speculation
+		optimizations.
+
+		More important, the rcu_dereference_sched() makes it
+		clear to someone reading the code that the pointer is
+		being protected by RCU-sched.

trunk/Documentation/RCU/checklist.txt

@@ -260,7 +260,8 @@ over a rather long period of time, but improvements are always welcome!
 	The reason that it is permissible to use RCU list-traversal
 	primitives when the update-side lock is held is that doing so
 	can be quite helpful in reducing code bloat when common code is
-	shared between readers and updaters.
+	shared between readers and updaters.  Additional primitives
+	are provided for this case, as discussed in lockdep.txt.
 
 10.	Conversely, if you are in an RCU read-side critical section,
 	and you don't hold the appropriate update-side lock, you -must-
@@ -344,8 +345,8 @@ over a rather long period of time, but improvements are always welcome!
 	requiring SRCU's read-side deadlock immunity or low read-side
 	realtime latency.
 
-	Note that, rcu_assign_pointer() and rcu_dereference() relate to
-	SRCU just as they do to other forms of RCU.
+	Note that, rcu_assign_pointer() relates to SRCU just as they do
+	to other forms of RCU.
 
 15.	The whole point of call_rcu(), synchronize_rcu(), and friends
 	is to wait until all pre-existing readers have finished before

trunk/Documentation/RCU/lockdep.txt

@@ -32,9 +32,20 @@ checking of rcu_dereference() primitives:
 	srcu_dereference(p, sp):
 		Check for SRCU read-side critical section.
 	rcu_dereference_check(p, c):
-		Use explicit check expression "c".
+		Use explicit check expression "c".  This is useful in
+		code that is invoked by both readers and updaters.
 	rcu_dereference_raw(p)
 		Don't check.  (Use sparingly, if at all.)
+	rcu_dereference_protected(p, c):
+		Use explicit check expression "c", and omit all barriers
+		and compiler constraints.  This is useful when the data
+		structure cannot change, for example, in code that is
+		invoked only by updaters.
+	rcu_access_pointer(p):
+		Return the value of the pointer and omit all barriers,
+		but retain the compiler constraints that prevent duplicating
+		or coalescsing.  This is useful when when testing the
+		value of the pointer itself, for example, against NULL.
 
 The rcu_dereference_check() check expression can be any boolean
 expression, but would normally include one of the rcu_read_lock_held()
@@ -59,7 +70,20 @@ In case (1), the pointer is picked up in an RCU-safe manner for vanilla
 RCU read-side critical sections, in case (2) the ->file_lock prevents
 any change from taking place, and finally, in case (3) the current task
 is the only task accessing the file_struct, again preventing any change
-from taking place.
+from taking place.  If the above statement was invoked only from updater
+code, it could instead be written as follows:
+
+	file = rcu_dereference_protected(fdt->fd[fd],
+					 lockdep_is_held(&files->file_lock) ||
+					 atomic_read(&files->count) == 1);
+
+This would verify cases #2 and #3 above, and furthermore lockdep would
+complain if this was used in an RCU read-side critical section unless one
+of these two cases held.  Because rcu_dereference_protected() omits all
+barriers and compiler constraints, it generates better code than do the
+other flavors of rcu_dereference().  On the other hand, it is illegal
+to use rcu_dereference_protected() if either the RCU-protected pointer
+or the RCU-protected data that it points to can change concurrently.
 
 There are currently only "universal" versions of the rcu_assign_pointer()
 and RCU list-/tree-traversal primitives, which do not (yet) check for

trunk/Documentation/RCU/whatisRCU.txt

@@ -840,6 +840,12 @@ SRCU:	Initialization/cleanup
 	init_srcu_struct
 	cleanup_srcu_struct
 
+All:  lockdep-checked RCU-protected pointer access
+
+	rcu_dereference_check
+	rcu_dereference_protected
+	rcu_access_pointer
+
 See the comment headers in the source code (or the docbook generated
 from them) for more information.
 

trunk/Documentation/block/biodoc.txt

@@ -1162,8 +1162,8 @@ where a driver received a request ala this before:
 
 As mentioned, there is no virtual mapping of a bio. For DMA, this is
 not a problem as the driver probably never will need a virtual mapping.
-Instead it needs a bus mapping (pci_map_page for a single segment or
-use blk_rq_map_sg for scatter gather) to be able to ship it to the driver. For
+Instead it needs a bus mapping (dma_map_page for a single segment or
+use dma_map_sg for scatter gather) to be able to ship it to the driver. For
 PIO drivers (or drivers that need to revert to PIO transfer once in a
 while (IDE for example)), where the CPU is doing the actual data
 transfer a virtual mapping is needed. If the driver supports highmem I/O,

trunk/Documentation/cgroups/cgroups.txt

@@ -235,8 +235,7 @@ containing the following files describing that cgroup:
  - cgroup.procs: list of tgids in the cgroup.  This list is not
    guaranteed to be sorted or free of duplicate tgids, and userspace
    should sort/uniquify the list if this property is required.
-   Writing a tgid into this file moves all threads with that tgid into
-   this cgroup.
+   This is a read-only file, for now.
  - notify_on_release flag: run the release agent on exit?
  - release_agent: the path to use for release notifications (this file
    exists in the top cgroup only)

trunk/Documentation/connector/cn_test.c

@@ -25,6 +25,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/skbuff.h>
+#include <linux/slab.h>
 #include <linux/timer.h>
 
 #include <linux/connector.h>

trunk/Documentation/fb/imacfb.txt → trunk/Documentation/fb/efifb.txt

@@ -1,9 +1,9 @@
 
-What is imacfb?
+What is efifb?
 ===============
 
 This is a generic EFI platform driver for Intel based Apple computers.
-Imacfb is only for EFI booted Intel Macs.
+efifb is only for EFI booted Intel Macs.
 
 Supported Hardware
 ==================
@@ -16,16 +16,16 @@ MacMini
 How to use it?
 ==============
 
-Imacfb does not have any kind of autodetection of your machine.
+efifb does not have any kind of autodetection of your machine.
 You have to add the following kernel parameters in your elilo.conf:
 	Macbook :
-		video=imacfb:macbook
+		video=efifb:macbook
 	MacMini :
-		video=imacfb:mini
+		video=efifb:mini
 	Macbook Pro 15", iMac 17" :
-		video=imacfb:i17
+		video=efifb:i17
 	Macbook Pro 17", iMac 20" :
-		video=imacfb:i20
+		video=efifb:i20
 
 --
 Edgar Hucek <gimli@dark-green.com>

trunk/Documentation/filesystems/9p.txt

@@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9)
 
 	mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
 
+For server running on QEMU host with virtio transport:
+
+	mount -t 9p -o trans=virtio <mount_tag> /mnt/9
+
+where mount_tag is the tag associated by the server to each of the exported
+mount points. Each 9P export is seen by the client as a virtio device with an
+associated "mount_tag" property. Available mount tags can be
+seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
+
 OPTIONS
 =======
 
@@ -47,7 +56,7 @@ OPTIONS
 			fd   	- used passed file descriptors for connection
                                 (see rfdno and wfdno)
 			virtio	- connect to the next virtio channel available
-				(from lguest or KVM with trans_virtio module)
+				(from QEMU with trans_virtio module)
 			rdma	- connect to a specified RDMA channel
 
   uname=name	user name to attempt mount as on the remote server.  The
@@ -85,7 +94,12 @@ OPTIONS
 
   port=n	port to connect to on the remote server
 
-  noextend	force legacy mode (no 9p2000.u semantics)
+  noextend	force legacy mode (no 9p2000.u or 9p2000.L semantics)
+
+  version=name	Select 9P protocol version. Valid options are:
+			9p2000          - Legacy mode (same as noextend)
+			9p2000.u        - Use 9P2000.u protocol
+			9p2000.L        - Use 9P2000.L protocol
 
   dfltuid	attempt to mount as a particular uid
 

trunk/Documentation/input/multi-touch-protocol.txt

@@ -68,6 +68,22 @@ like:
    SYN_MT_REPORT
    SYN_REPORT
 
+Here is the sequence after lifting one of the fingers:
+
+   ABS_MT_POSITION_X
+   ABS_MT_POSITION_Y
+   SYN_MT_REPORT
+   SYN_REPORT
+
+And here is the sequence after lifting the remaining finger:
+
+   SYN_MT_REPORT
+   SYN_REPORT
+
+If the driver reports one of BTN_TOUCH or ABS_PRESSURE in addition to the
+ABS_MT events, the last SYN_MT_REPORT event may be omitted. Otherwise, the
+last SYN_REPORT will be dropped by the input core, resulting in no
+zero-finger event reaching userland.
 
 Event Semantics
 ---------------
@@ -217,11 +233,6 @@ where examples can be found.
 difference between the contact position and the approaching tool position
 could be used to derive tilt.
 [2] The list can of course be extended.
-[3] The multi-touch X driver is currently in the prototyping stage. At the
-time of writing (April 2009), the MT protocol is not yet merged, and the
-prototype implements finger matching, basic mouse support and two-finger
-scrolling. The project aims at improving the quality of current multi-touch
-functionality available in the Synaptics X driver, and in addition
-implement more advanced gestures.
+[3] Multitouch X driver project: http://bitmath.org/code/multitouch/.
 [4] See the section on event computation.
 [5] See the section on finger tracking.

trunk/Documentation/kernel-parameters.txt

@@ -320,11 +320,6 @@ and is between 256 and 4096 characters. It is defined in the file
 	amd_iommu=	[HW,X86-84]
 			Pass parameters to the AMD IOMMU driver in the system.
 			Possible values are:
-			isolate - enable device isolation (each device, as far
-			          as possible, will get its own protection
-			          domain) [default]
-			share - put every device behind one IOMMU into the
-				same protection domain
 			fullflush - enable flushing of IO/TLB entries when
 				    they are unmapped. Otherwise they are
 				    flushed before they will be reused, which
@@ -1199,7 +1194,7 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	libata.force=	[LIBATA] Force configurations.  The format is comma
 			separated list of "[ID:]VAL" where ID is
-			PORT[:DEVICE].  PORT and DEVICE are decimal numbers
+			PORT[.DEVICE].  PORT and DEVICE are decimal numbers
 			matching port, link or device.  Basically, it matches
 			the ATA ID string printed on console by libata.  If
 			the whole ID part is omitted, the last PORT and DEVICE