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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-03-07 07:30:58 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-12 08:23:42 -0700 |
| commit | 066bb1c84aa430d15f36070471cbfe8976631cce (patch) | |
| tree | e32228f6dfda4dbf3d53666771f2e7f3520563ec /Documentation/RCU/whatisRCU.txt | |
| parent | 6771853bce3f0f7f17cab257b47f5b77b1c625b1 (diff) | |
| download | linux-066bb1c84aa430d15f36070471cbfe8976631cce.tar.bz2 | |
doc: Update rcu_assign_pointer() definition in whatisRCU.txt
The rcu_assign_pointer() macro has changed over time, and the version
in Documentation/RCU/whatisRCU.txt has not kept up. This commit brings
it into 2017, albeit in a simplified fashion.
Reported-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation/RCU/whatisRCU.txt')
| -rw-r--r-- | Documentation/RCU/whatisRCU.txt | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 5cbd8b2395b8..6b0337008f9c 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -587,20 +587,21 @@ It is extremely simple: write_unlock(&rcu_gp_mutex); } -[You can ignore rcu_assign_pointer() and rcu_dereference() without -missing much. But here they are anyway. And whatever you do, don't -forget about them when submitting patches making use of RCU!] - - #define rcu_assign_pointer(p, v) ({ \ - smp_wmb(); \ - (p) = (v); \ - }) - - #define rcu_dereference(p) ({ \ - typeof(p) _________p1 = p; \ - smp_read_barrier_depends(); \ - (_________p1); \ - }) +[You can ignore rcu_assign_pointer() and rcu_dereference() without missing +much. But here are simplified versions anyway. And whatever you do, +don't forget about them when submitting patches making use of RCU!] + + #define rcu_assign_pointer(p, v) \ + ({ \ + smp_store_release(&(p), (v)); \ + }) + + #define rcu_dereference(p) \ + ({ \ + typeof(p) _________p1 = p; \ + smp_read_barrier_depends(); \ + (_________p1); \ + }) The rcu_read_lock() and rcu_read_unlock() primitive read-acquire |