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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-11-27 09:20:40 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-12-05 11:57:53 -0800 |
| commit | 9ad3c143d7d6942c66f27bc6c18f5df638f70aff (patch) | |
| tree | b0b52f72cd5d03677b2d643feaaa7220aa109f29 /Documentation/circular-buffers.txt | |
| parent | 98c1ec7cefaadbf65680d116c3d8612b93a841a0 (diff) | |
| download | lwn-9ad3c143d7d6942c66f27bc6c18f5df638f70aff.tar.gz lwn-9ad3c143d7d6942c66f27bc6c18f5df638f70aff.zip | |
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/circular-buffers.txt')
| -rw-r--r-- | Documentation/circular-buffers.txt | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/Documentation/circular-buffers.txt b/Documentation/circular-buffers.txt index d4628174b7c5..53e51caa3347 100644 --- a/Documentation/circular-buffers.txt +++ b/Documentation/circular-buffers.txt @@ -220,8 +220,7 @@ before it writes the new tail pointer, which will erase the item. Note the use of READ_ONCE() and smp_load_acquire() to read the opposition index. This prevents the compiler from discarding and -reloading its cached value - which some compilers will do across -smp_read_barrier_depends(). This isn't strictly needed if you can +reloading its cached value. This isn't strictly needed if you can be sure that the opposition index will _only_ be used the once. The smp_load_acquire() additionally forces the CPU to order against subsequent memory references. Similarly, smp_store_release() is used |