Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH v2 tip/core/rcu 4/8] documentation: Composability analogies | Date | Wed, 9 Dec 2015 15:14:58 -0800 |
| |
This commit expands on RCU's composability by comparing it to that of transactional memory and of locking.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> --- Documentation/RCU/Design/Requirements/Requirements.html | 8 ++++++++ Documentation/RCU/Design/Requirements/Requirements.htmlx | 8 ++++++++ 2 files changed, 16 insertions(+)
diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html index cc5b587c0ec5..105247149975 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.html +++ b/Documentation/RCU/Design/Requirements/Requirements.html @@ -1495,6 +1495,14 @@ section, neither of which is conducive to a long-lived and prosperous kernel. <p> +It is worth noting that RCU is not alone in limiting composability. +For example, many transactional-memory implementations prohibit +composing a pair of transactions separated by an irrevocable +operation (for example, a network receive operation). +For another example, lock-based critical sections can be composed +surprisingly freely, but only if deadlock is avoided. + +<p> In short, although RCU read-side critical sections are highly composable, care is required in some situations, just as is the case for any other composable synchronization mechanism. diff --git a/Documentation/RCU/Design/Requirements/Requirements.htmlx b/Documentation/RCU/Design/Requirements/Requirements.htmlx index 23524d75a3c3..5b76e21fa092 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.htmlx +++ b/Documentation/RCU/Design/Requirements/Requirements.htmlx @@ -1654,6 +1654,14 @@ section, neither of which is conducive to a long-lived and prosperous kernel. <p> +It is worth noting that RCU is not alone in limiting composability. +For example, many transactional-memory implementations prohibit +composing a pair of transactions separated by an irrevocable +operation (for example, a network receive operation). +For another example, lock-based critical sections can be composed +surprisingly freely, but only if deadlock is avoided. + +<p> In short, although RCU read-side critical sections are highly composable, care is required in some situations, just as is the case for any other composable synchronization mechanism. -- 2.5.2
| |