From 9ad3c143d7d6942c66f27bc6c18f5df638f70aff Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 27 Nov 2017 09:20:40 -0800 Subject: 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: Adjusted to allow for David Howells feedback on prior commit. ] --- Documentation/circular-buffers.txt | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'Documentation/circular-buffers.txt') 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 -- cgit