From d19720a909b4443f78cbb03f4f090180e143ad9d Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 1 Feb 2006 03:06:42 -0800 Subject: [PATCH] RCU documentation fixes (January 2006 update) Updates to in-tree RCU documentation based on comments over the past few months. Signed-off-by: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/RCU/RTFP.txt | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) (limited to 'Documentation/RCU/RTFP.txt') diff --git a/Documentation/RCU/RTFP.txt b/Documentation/RCU/RTFP.txt index fcbcbc3..6221464 100644 --- a/Documentation/RCU/RTFP.txt +++ b/Documentation/RCU/RTFP.txt @@ -90,16 +90,20 @@ at OLS. The resulting abundance of RCU patches was presented the following year [McKenney02a], and use of RCU in dcache was first described that same year [Linder02a]. -Also in 2002, Michael [Michael02b,Michael02a] presented techniques -that defer the destruction of data structures to simplify non-blocking -synchronization (wait-free synchronization, lock-free synchronization, -and obstruction-free synchronization are all examples of non-blocking -synchronization). In particular, this technique eliminates locking, -reduces contention, reduces memory latency for readers, and parallelizes -pipeline stalls and memory latency for writers. However, these -techniques still impose significant read-side overhead in the form of -memory barriers. Researchers at Sun worked along similar lines in the -same timeframe [HerlihyLM02,HerlihyLMS03]. +Also in 2002, Michael [Michael02b,Michael02a] presented "hazard-pointer" +techniques that defer the destruction of data structures to simplify +non-blocking synchronization (wait-free synchronization, lock-free +synchronization, and obstruction-free synchronization are all examples of +non-blocking synchronization). In particular, this technique eliminates +locking, reduces contention, reduces memory latency for readers, and +parallelizes pipeline stalls and memory latency for writers. However, +these techniques still impose significant read-side overhead in the +form of memory barriers. Researchers at Sun worked along similar lines +in the same timeframe [HerlihyLM02,HerlihyLMS03]. These techniques +can be thought of as inside-out reference counts, where the count is +represented by the number of hazard pointers referencing a given data +structure (rather than the more conventional counter field within the +data structure itself). In 2003, the K42 group described how RCU could be used to create hot-pluggable implementations of operating-system functions. Later that @@ -113,7 +117,6 @@ number of operating-system kernels [PaulEdwardMcKenneyPhD], a paper describing how to make RCU safe for soft-realtime applications [Sarma04c], and a paper describing SELinux performance with RCU [JamesMorris04b]. - 2005 has seen further adaptation of RCU to realtime use, permitting preemption of RCU realtime critical sections [PaulMcKenney05a, PaulMcKenney05b]. -- cgit v1.1