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author | Kees Cook <keescook@chromium.org> | 2012-10-19 16:48:30 (GMT) |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-11-08 19:44:25 (GMT) |
commit | 57d34a6cee1399bfedaa73add1915951cbe75cab (patch) | |
tree | b1ace739f62f0e8217b4213a8cdda9fc46f9b27e /Documentation/RCU/whatisRCU.txt | |
parent | 0f9574d83234274c4d8f8f742b45022e5718b16e (diff) | |
download | linux-fsl-qoriq-57d34a6cee1399bfedaa73add1915951cbe75cab.tar.xz |
rcu: Update docs to include kfree_rcu()
Mention kfree_rcu() in the call_rcu() section. Additionally fix the
example code for list replacement that used the wrong structure element.
Signed-off-by: Kees Cook <keescook@chromium.org>
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 | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index bf0f6de..160ac55 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -499,6 +499,8 @@ The foo_reclaim() function might appear as follows: { struct foo *fp = container_of(rp, struct foo, rcu); + foo_cleanup(fp->a); + kfree(fp); } @@ -521,6 +523,12 @@ o Use call_rcu() -after- removing a data element from an read-side critical sections that might be referencing that data item. +If the callback for call_rcu() is not doing anything more than calling +kfree() on the structure, you can use kfree_rcu() instead of call_rcu() +to avoid having to write your own callback: + + kfree_rcu(old_fp, rcu); + Again, see checklist.txt for additional rules governing the use of RCU. @@ -773,8 +781,8 @@ a single atomic update, converting to RCU will require special care. Also, the presence of synchronize_rcu() means that the RCU version of delete() can now block. If this is a problem, there is a callback-based -mechanism that never blocks, namely call_rcu(), that can be used in -place of synchronize_rcu(). +mechanism that never blocks, namely call_rcu() or kfree_rcu(), that can +be used in place of synchronize_rcu(). 7. FULL LIST OF RCU APIs @@ -813,6 +821,7 @@ RCU: Critical sections Grace period Barrier rcu_read_unlock synchronize_rcu rcu_dereference synchronize_rcu_expedited call_rcu + kfree_rcu bh: Critical sections Grace period Barrier |