Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ef48bd246124ccdef0e1fa5b03b62d69cbf71fa7 Commit: ef48bd246124ccdef0e1fa5b03b62d69cbf71fa7 Parent: 4d3b573ad9af85b6df104044f6fff05f04349db2 Author: Paul E. McKenney <[EMAIL PROTECTED]> AuthorDate: Sun Jul 15 23:41:03 2007 -0700 Committer: Linus Torvalds <[EMAIL PROTECTED]> CommitDate: Mon Jul 16 09:05:47 2007 -0700
Document the fact that RCU callbacks can run in parallel Add an item to the RCU documentation checklist noting that RCU callbacks can run in parallel. Signed-off-by: Paul E. McKenney <[EMAIL PROTECTED]> Cc: Steven Rostedt <[EMAIL PROTECTED]> Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]> --- Documentation/RCU/checklist.txt | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt index f4dffad..42b01bc 100644 --- a/Documentation/RCU/checklist.txt +++ b/Documentation/RCU/checklist.txt @@ -222,7 +222,15 @@ over a rather long period of time, but improvements are always welcome! deadlock as soon as the RCU callback happens to interrupt that acquisition's critical section. -13. SRCU (srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu()) +13. RCU callbacks can be and are executed in parallel. In many cases, + the callback code simply wrappers around kfree(), so that this + is not an issue (or, more accurately, to the extent that it is + an issue, the memory-allocator locking handles it). However, + if the callbacks do manipulate a shared data structure, they + must use whatever locking or other synchronization is required + to safely access and/or modify that data structure. + +14. SRCU (srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu()) may only be invoked from process context. Unlike other forms of RCU, it -is- permissible to block in an SRCU read-side critical section (demarked by srcu_read_lock() and srcu_read_unlock()), - To unsubscribe from this list: send the line "unsubscribe git-commits-head" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html