diff options
author | Tejun Heo <tj@kernel.org> | 2011-05-02 14:08:43 +0200 |
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committer | Tejun Heo <tj@kernel.org> | 2011-05-02 14:08:47 +0200 |
commit | aff364860aa105b2deacc6f21ec8ef524460e3fc (patch) | |
tree | 18409ebe16b25b141598da9b6386d69416c06afa /include/linux/rcupdate.h | |
parent | c7a7b814c9dca9ee01b38e63b4a46de87156d3b6 (diff) | |
parent | 993ba1585cbb03fab012e41d1a5d24330a283b31 (diff) |
Merge branch 'x86/numa' into x86-mm
Merge reason: Pick up x86-32 remap allocator cleanup changes - 14
commits, 3fe14ab541^..993ba1585c.
3fe14ab541: x86-32, numa: Fix failure condition check in alloc_remap()
993ba1585c: x86-32, numa: Update remap allocator comments
Scheduled NUMA init 32/64bit unification changes depend on them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/rcupdate.h')
-rw-r--r-- | include/linux/rcupdate.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index af561485628..ff422d2b7f9 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -339,6 +339,12 @@ extern int rcu_my_thread_group_empty(void); ((typeof(*p) __force __kernel *)(p)); \ }) +#define __rcu_access_index(p, space) \ + ({ \ + typeof(p) _________p1 = ACCESS_ONCE(p); \ + rcu_dereference_sparse(p, space); \ + (_________p1); \ + }) #define __rcu_dereference_index_check(p, c) \ ({ \ typeof(p) _________p1 = ACCESS_ONCE(p); \ @@ -429,6 +435,20 @@ extern int rcu_my_thread_group_empty(void); #define rcu_dereference_raw(p) rcu_dereference_check(p, 1) /*@@@ needed? @@@*/ /** + * rcu_access_index() - fetch RCU index with no dereferencing + * @p: The index to read + * + * Return the value of the specified RCU-protected index, but omit the + * smp_read_barrier_depends() and keep the ACCESS_ONCE(). This is useful + * when the value of this index is accessed, but the index is not + * dereferenced, for example, when testing an RCU-protected index against + * -1. Although rcu_access_index() may also be used in cases where + * update-side locks prevent the value of the index from changing, you + * should instead use rcu_dereference_index_protected() for this use case. + */ +#define rcu_access_index(p) __rcu_access_index((p), __rcu) + +/** * rcu_dereference_index_check() - rcu_dereference for indices with debug checking * @p: The pointer to read, prior to dereferencing * @c: The conditions under which the dereference will take place |