Commit-ID: fb2b581968db140586e8d7db38ff278f60872313 Gitweb: http://git.kernel.org/tip/fb2b581968db140586e8d7db38ff278f60872313 Author: Paul E. McKenney <[email protected]> AuthorDate: Wed, 11 Dec 2013 13:59:05 -0800 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 16 Dec 2013 11:36:09 +0100
Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt Although the atomic_long_t functions are quite useful, they are a bit obscure. This commit therefore adds the common ones alongside their atomic_t counterparts in Documentation/memory-barriers.txt. Signed-off-by: Paul E. McKenney <[email protected]> Reviewed-by: Josh Triplett <[email protected]> Reviewed-by: Peter Zijlstra <[email protected]> Cc: <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Andrew Morton <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- Documentation/memory-barriers.txt | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 1d06723..2d22da0 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1728,21 +1728,23 @@ explicit lock operations, described later). These include: xchg(); cmpxchg(); - atomic_xchg(); - atomic_cmpxchg(); - atomic_inc_return(); - atomic_dec_return(); - atomic_add_return(); - atomic_sub_return(); - atomic_inc_and_test(); - atomic_dec_and_test(); - atomic_sub_and_test(); - atomic_add_negative(); - atomic_add_unless(); /* when succeeds (returns 1) */ + atomic_xchg(); atomic_long_xchg(); + atomic_cmpxchg(); atomic_long_cmpxchg(); + atomic_inc_return(); atomic_long_inc_return(); + atomic_dec_return(); atomic_long_dec_return(); + atomic_add_return(); atomic_long_add_return(); + atomic_sub_return(); atomic_long_sub_return(); + atomic_inc_and_test(); atomic_long_inc_and_test(); + atomic_dec_and_test(); atomic_long_dec_and_test(); + atomic_sub_and_test(); atomic_long_sub_and_test(); + atomic_add_negative(); atomic_long_add_negative(); test_and_set_bit(); test_and_clear_bit(); test_and_change_bit(); + /* when succeeds (returns 1) */ + atomic_add_unless(); atomic_long_add_unless(); + These are used for such things as implementing LOCK-class and UNLOCK-class operations and adjusting reference counters towards object destruction, and as such the implicit memory barrier effects are necessary. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
