Documentation/memory-barriers.txt: Fix a typo in the data dependency description

This typo has been there forever, it is 7.5 years old, looks like this
section of our memory ordering documentation is a place where most eyes
are glazed over already ;-)

[ Also fix some stray spaces and stray tabs while at it, shrinking the
  file by 49 bytes. Visual output unchanged. ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-gncea9cb8igosblizfqMXrie@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index c8c42e6..020cccd 100644 (file)
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -500,7 +500,7 @@ odd-numbered bank is idle, one can see the new value of the pointer P (&B),
 but the old value of the variable B (2).
 
 
-Another example of where data dependency barriers might by required is where a
+Another example of where data dependency barriers might be required is where a
 number is read from memory and then used to calculate the index for an array
 access:
 
@@ -882,12 +882,12 @@ cache it for later use.
 
 Consider:
 
-       CPU 1                   CPU 2
+       CPU 1                   CPU 2
        ======================= =======================
-                               LOAD B
-                               DIVIDE          } Divide instructions generally
-                               DIVIDE          } take a long time to perform
-                               LOAD A
+                               LOAD B
+                               DIVIDE          } Divide instructions generally
+                               DIVIDE          } take a long time to perform
+                               LOAD A
 
 Which might appear as this:
 
@@ -910,13 +910,13 @@ Which might appear as this:
 Placing a read barrier or a data dependency barrier just before the second
 load:
 
-       CPU 1                   CPU 2
+       CPU 1                   CPU 2
        ======================= =======================
-                               LOAD B
-                               DIVIDE
-                               DIVIDE
+                               LOAD B
+                               DIVIDE
+                               DIVIDE
                                <read barrier>
-                               LOAD A
+                               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
@@ -1887,8 +1887,8 @@ functions:
      space should suffice for PCI.
 
      [*] NOTE! attempting to load from the same location as was written to may
-        cause a malfunction - consider the 16550 Rx/Tx serial registers for
-        example.
+        cause a malfunction - consider the 16550 Rx/Tx serial registers for
+        example.
 
      Used with prefetchable I/O memory, an mmiowb() barrier may be required to
      force stores to be ordered.
@@ -1955,19 +1955,19 @@ barriers for the most part act at the interface between the CPU and its cache
                                  :
        +--------+    +--------+  :   +--------+    +-----------+
        |        |    |        |  :   |        |    |           |    +--------+
-       |  CPU   |    | Memory |  :   | CPU    |    |           |    |        |
-       |  Core  |--->| Access |----->| Cache  |<-->|           |    |        |
+       |  CPU   |    | Memory |  :   | CPU    |    |           |    |        |
+       |  Core  |--->| Access |----->| Cache  |<-->|           |    |        |
        |        |    | Queue  |  :   |        |    |           |--->| Memory |
-       |        |    |        |  :   |        |    |           |    |        |
-       +--------+    +--------+  :   +--------+    |           |    |        |
+       |        |    |        |  :   |        |    |           |    |        |
+       +--------+    +--------+  :   +--------+    |           |    |        |
                                  :                 | Cache     |    +--------+
                                  :                 | Coherency |
                                  :                 | Mechanism |    +--------+
        +--------+    +--------+  :   +--------+    |           |    |        |
        |        |    |        |  :   |        |    |           |    |        |
        |  CPU   |    | Memory |  :   | CPU    |    |           |--->| Device |
-       |  Core  |--->| Access |----->| Cache  |<-->|           |    |        |
-       |        |    | Queue  |  :   |        |    |           |    |        |
+       |  Core  |--->| Access |----->| Cache  |<-->|           |    |        |
+       |        |    | Queue  |  :   |        |    |           |    |        |
        |        |    |        |  :   |        |    |           |    +--------+
        +--------+    +--------+  :   +--------+    +-----------+
                                  :
@@ -2090,7 +2090,7 @@ CPU's caches by some other cache event:
        p = &v;         q = p;
                        <D:request p>
        <B:modify p=&v> <D:commit p=&v>
-                       <D:read p>
+                       <D:read p>
                        x = *q;
                        <C:read *q>     Reads from v before v updated in cache
                        <C:unbusy>
@@ -2115,7 +2115,7 @@ queue before processing any further requests:
        p = &v;         q = p;
                        <D:request p>
        <B:modify p=&v> <D:commit p=&v>
-                       <D:read p>
+                       <D:read p>
                        smp_read_barrier_depends()
                        <C:unbusy>
                        <C:commit v=2>