summaryrefslogtreecommitdiff
path: root/Documentation/RCU/rcu_dereference.txt
diff options
context:
space:
mode:
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-11-27 20:20:40 +0300
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-12-05 22:57:53 +0300
commit9ad3c143d7d6942c66f27bc6c18f5df638f70aff (patch)
treeb0b52f72cd5d03677b2d643feaaa7220aa109f29 /Documentation/RCU/rcu_dereference.txt
parent98c1ec7cefaadbf65680d116c3d8612b93a841a0 (diff)
downloadlinux-9ad3c143d7d6942c66f27bc6c18f5df638f70aff.tar.xz
doc: De-emphasize smp_read_barrier_depends
This commit keeps only the historical and low-level discussion of smp_read_barrier_depends(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: Adjusted to allow for David Howells feedback on prior commit. ]
Diffstat (limited to 'Documentation/RCU/rcu_dereference.txt')
-rw-r--r--Documentation/RCU/rcu_dereference.txt6
1 files changed, 1 insertions, 5 deletions
diff --git a/Documentation/RCU/rcu_dereference.txt b/Documentation/RCU/rcu_dereference.txt
index 1acb26b09b48..ab96227bad42 100644
--- a/Documentation/RCU/rcu_dereference.txt
+++ b/Documentation/RCU/rcu_dereference.txt
@@ -122,11 +122,7 @@ o Be very careful about comparing pointers obtained from
Note that if checks for being within an RCU read-side
critical section are not required and the pointer is never
dereferenced, rcu_access_pointer() should be used in place
- of rcu_dereference(). The rcu_access_pointer() primitive
- does not require an enclosing read-side critical section,
- and also omits the smp_read_barrier_depends() included in
- rcu_dereference(), which in turn should provide a small
- performance gain in some CPUs (e.g., the DEC Alpha).
+ of rcu_dereference().
o The comparison is against a pointer that references memory
that was initialized "a long time ago." The reason