Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

5928a2b6 · Linus Torvalds <[email protected]> · 2012-03-19 17:12:34 -07:00

Pull RCU changes for v3.4 from Ingo Molnar.  The major features of this
series are:

 - making RCU more aggressive about entering dyntick-idle mode in order
   to improve energy efficiency

 - converting a few more call_rcu()s to kfree_rcu()s

 - applying a number of rcutree fixes and cleanups to rcutiny

 - removing CONFIG_SMP #ifdefs from treercu

 - allowing RCU CPU stall times to be set via sysfs

 - adding CPU-stall capability to rcutorture

 - adding more RCU-abuse diagnostics

 - updating documentation

 - fixing yet more issues located by the still-ongoing top-to-bottom
   inspection of RCU, this time with a special focus on the CPU-hotplug
   code path.

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  rcu: Stop spurious warnings from synchronize_sched_expedited
  rcu: Hold off RCU_FAST_NO_HZ after timer posted
  rcu: Eliminate softirq-mediated RCU_FAST_NO_HZ idle-entry loop
  rcu: Add RCU_NONIDLE() for idle-loop RCU read-side critical sections
  rcu: Allow nesting of rcu_idle_enter() and rcu_idle_exit()
  rcu: Remove redundant check for rcu_head misalignment
  PTR_ERR should be called before its argument is cleared.
  rcu: Convert WARN_ON_ONCE() in rcu_lock_acquire() to lockdep
  rcu: Trace only after NULL-pointer check
  rcu: Call out dangers of expedited RCU primitives
  rcu: Rework detection of use of RCU by offline CPUs
  lockdep: Add CPU-idle/offline warning to lockdep-RCU splat
  rcu: No interrupt disabling for rcu_prepare_for_idle()
  rcu: Move synchronize_sched_expedited() to rcutree.c
  rcu: Check for illegal use of RCU from offlined CPUs
  rcu: Update stall-warning documentation
  rcu: Add CPU-stall capability to rcutorture
  rcu: Make documentation give more realistic rcutorture duration
  rcutorture: Permit holding off CPU-hotplug operations during boot
  rcu: Print scheduling-clock information on RCU CPU stall-warning messages
  ...

Commit: 5928a2b60cfdbad730f93696acab142d0b607280
Parents: 5ed59af8 · bdd4431c

Merge commit. Changes below are compared with the first parent: 5ed59af8.

Changes

29 files changed · +2965 −642

File	Status	Add	Del	Content
Documentation/RCU/RTFP.txt	modified	+1745	−157	View file
Documentation/RCU/checklist.txt	modified	+14	−0	View file
Documentation/RCU/stallwarn.txt	modified	+80	−7	View file
Documentation/RCU/torture.txt	modified	+30	−3	View file
Documentation/RCU/trace.txt	modified	+16	−20	View file
arch/s390/kernel/irq.c	modified	+1	−8	View file
drivers/target/tcm_fc/tfc_sess.c	modified	+1	−11	View file
include/linux/rcupdate.h	modified	+80	−3	View file
include/linux/rcutiny.h	modified	+6	−4	View file
include/linux/rcutree.h	modified	+19	−0	View file
include/linux/sched.h	modified	+1	−2	View file
include/linux/srcu.h	modified	+11	−4	View file
include/trace/events/rcu.h	modified	+39	−24	View file
init/Kconfig	modified	+0	−9	View file
kernel/lockdep.c	modified	+7	−1	View file
kernel/rcu.h	modified	+23	−3	View file
kernel/rcupdate.c	modified	+5	−0	View file
kernel/rcutiny.c	modified	+20	−6	View file
kernel/rcutiny_plugin.h	modified	+60	−17	View file
kernel/rcutorture.c	modified	+86	−5	View file
kernel/rcutree.c	modified	+371	−136	View file
kernel/rcutree.h	modified	+16	−11	View file
kernel/rcutree_plugin.h	modified	+276	−174	View file
kernel/rcutree_trace.c	modified	+6	−6	View file
kernel/srcu.c	modified	+23	−10	View file
lib/Kconfig.debug	modified	+24	−0	View file
net/ipv4/cipso_ipv4.c	modified	+3	−8	View file
net/ipv4/ip_sockglue.c	modified	+1	−6	View file
net/mac80211/mesh_pathtbl.c	modified	+1	−7	View file

Only the first 600 diff lines are shown. Download the complete patch.

Documentation/RCU/RTFP.txt

View file

diff --git a/Documentation/RCU/RTFP.txt b/Documentation/RCU/RTFP.txt
index c43460d..7c1dfb1 100644
--- a/Documentation/RCU/RTFP.txt
+++ b/Documentation/RCU/RTFP.txt
@@ -1,9 +1,10 @@
-Read the F-ing Papers!
+Read the Fscking Papers!
 
 
 This document describes RCU-related publications, and is followed by
 the corresponding bibtex entries.  A number of the publications may
-be found at http://www.rdrop.com/users/paulmck/RCU/.
+be found at http://www.rdrop.com/users/paulmck/RCU/.  For others, browsers
+and search engines will usually find what you are looking for.
 
 The first thing resembling RCU was published in 1980, when Kung and Lehman
 [Kung80] recommended use of a garbage collector to defer destruction
@@ -160,7 +161,26 @@ which Mathieu Desnoyers is now maintaining [MathieuDesnoyers2009URCU]
 [MathieuDesnoyersPhD].  TINY_RCU [PaulEMcKenney2009BloatWatchRCU] made
 its appearance, as did expedited RCU [PaulEMcKenney2009expeditedRCU].
 The problem of resizeable RCU-protected hash tables may now be on a path
-to a solution [JoshTriplett2009RPHash].
+to a solution [JoshTriplett2009RPHash].  A few academic researchers are now
+using RCU to solve their parallel problems [HariKannan2009DynamicAnalysisRCU].
+
+2010 produced a simpler preemptible-RCU implementation
+based on TREE_RCU [PaulEMcKenney2010SimpleOptRCU], lockdep-RCU
+[PaulEMcKenney2010LockdepRCU], another resizeable RCU-protected hash
+table [HerbertXu2010RCUResizeHash] (this one consuming more memory,
+but allowing arbitrary changes in hash function, as required for DoS
+avoidance in the networking code), realization of the 2009 RCU-protected
+hash table with atomic node move [JoshTriplett2010RPHash], an update on
+the RCU API [PaulEMcKenney2010RCUAPI].
+
+2011 marked the inclusion of Nick Piggin's fully lockless dentry search
+[LinusTorvalds2011Linux2:6:38:rc1:NPigginVFS], an RCU-protected red-black
+tree using software transactional memory to protect concurrent updates
+(strange, but true!) [PhilHoward2011RCUTMRBTree], yet another variant of
+RCU-protected resizeable hash tables [Triplett:2011:RPHash], the 3.0 RCU
+trainwreck [PaulEMcKenney2011RCU3.0trainwreck], and Neil Brown's "Meet the
+Lockers" LWN article [NeilBrown2011MeetTheLockers].
+
 
 Bibtex Entries
 
@@ -173,6 +193,14 @@ Bibtex Entries
 ,volume="5"
 ,number="3"
 ,pages="354-382"
+,note="Available:
+\url{http://portal.acm.org/citation.cfm?id=320619&dl=GUIDE,}
+[Viewed December 3, 2007]"
+,annotation={
+	Use garbage collector to clean up data after everyone is done with it.
+	.
+	Oldest use of something vaguely resembling RCU that I have found.
+}
 }
 
 @techreport{Manber82
@@ -184,6 +212,31 @@ Bibtex Entries
 ,number="82-01-01"
 ,month="January"
 ,pages="28"
+,annotation={
+	.
+	Superseded by Manber84.
+	.
+	Describes concurrent AVL tree implementation.  Uses a
+	garbage-collection mechanism to handle concurrent use and deletion
+	of nodes in the tree, but lacks the summary-of-execution-history
+	concept of read-copy locking.
+	.
+	Keeps full list of processes that were active when a given
+	node was to be deleted, and waits until all such processes have
+	-terminated- before allowing this node to be reused.  This is
+	not described in great detail -- one could imagine using process
+	IDs for this if the ID space was large enough that overlapping
+	never occurred.
+	.
+	This restriction makes this algorithm unsuitable for use in
+	systems comprised of long-lived processes.  It also produces
+	completely unacceptable overhead in systems with large numbers
+	of processes.  Finally, it is specific to AVL trees.
+	.
+	Cites Kung80, so not an independent invention, but the first
+	RCU-like usage that does not rely on an automatic garbage
+	collector.
+}
 }
 
 @article{Manber84
@@ -195,6 +248,74 @@ Bibtex Entries
 ,volume="9"
 ,number="3"
 ,pages="439-455"
+,annotation={
+	Describes concurrent AVL tree implementation.  Uses a
+	garbage-collection mechanism to handle concurrent use and deletion
+	of nodes in the tree, but lacks the summary-of-execution-history
+	concept of read-copy locking.
+	.
+	Keeps full list of processes that were active when a given
+	node was to be deleted, and waits until all such processes have
+	-terminated- before allowing this node to be reused.  This is
+	not described in great detail -- one could imagine using process
+	IDs for this if the ID space was large enough that overlapping
+	never occurred.
+	.
+	This restriction makes this algorithm unsuitable for use in
+	systems comprised of long-lived processes.  It also produces
+	completely unacceptable overhead in systems with large numbers
+	of processes.  Finally, it is specific to AVL trees.
+}
+}
+
+@Conference{RichardRashid87a
+,Author="Richard Rashid and Avadis Tevanian and Michael Young and
+David Golub and Robert Baron and David Black and William Bolosky and
+Jonathan Chew"
+,Title="Machine-Independent Virtual Memory Management for Paged
+Uniprocessor and Multiprocessor Architectures"
+,Booktitle="{2\textsuperscript{nd} Symposium on Architectural Support
+for Programming Languages and Operating Systems}"
+,Publisher="Association for Computing Machinery"
+,Month="October"
+,Year="1987"
+,pages="31-39"
+,Address="Palo Alto, CA"
+,note="Available:
+\url{http://www.cse.ucsc.edu/~randal/221/rashid-machvm.pdf}
+[Viewed February 17, 2005]"
+,annotation={
+	Describes lazy TLB flush, where one waits for each CPU to pass
+	through a scheduling-clock interrupt before reusing a given range
+	of virtual address.  Does not describe how one determines that
+	all CPUs have in fact taken such an interrupt, though there are
+	no shortage of straightforward methods for accomplishing this.
+	.
+	Note that it does not make sense to just wait a fixed amount of
+	time, since a given CPU might have interrupts disabled for an
+	extended amount of time.
+}
+}
+
+@article{BarbaraLiskov1988ArgusCACM
+,author = {Barbara Liskov}
+,title = {Distributed programming in {Argus}}
+,journal = {Commun. ACM}
+,volume = {31}
+,number = {3}
+,year = {1988}
+,issn = {0001-0782}
+,pages = {300--312}
+,doi = {http://doi.acm.org/10.1145/42392.42399}
+,publisher = {ACM}
+,address = {New York, NY, USA}
+,annotation= {
+	At the top of page 307: "Conflicts with deposits and withdrawals
+	are necessary if the reported total is to be up to date.  They
+	could be avoided by having total return a sum that is slightly
+	out of date."  Relies on semantics -- approximate numerical
+	values sometimes OK.
+}
 }
 
 @techreport{Hennessy89
@@ -216,6 +337,13 @@ Bibtex Entries
 ,year="1990"
 ,number="CS-TR-2222.1"
 ,month="June"
+,annotation={
+	Concurrent access to skip lists.  Has both weak and strong search.
+	Uses concept of ``garbage queue'', but has no real way of cleaning
+	the garbage efficiently.
+	.
+	Appears to be an independent invention of an RCU-like mechanism.
+}
 }
 
 @Book{Adams91
@@ -223,20 +351,15 @@ Bibtex Entries
 ,title="Concurrent Programming, Principles, and Practices"
 ,Publisher="Benjamin Cummins"
 ,Year="1991"
+,annotation={
+	Has a few paragraphs describing ``chaotic relaxation'', a
+	numerical analysis technique that allows multiprocessors to
+	avoid synchronization overhead by using possibly-stale data.
+	.
+	Seems like this is descended from yet another independent
+	invention of RCU-like function -- but this is restricted
+	in that reclamation is not necessary.
 }
-
-@phdthesis{HMassalinPhD
-,author="H. Massalin"
-,title="Synthesis: An Efficient Implementation of Fundamental Operating
-System Services"
-,school="Columbia University"
-,address="New York, NY"
-,year="1992"
-,annotation="
-	Mondo optimizing compiler.
-	Wait-free stuff.
-	Good advice: defer work to avoid synchronization.
-"
 }
 
 @unpublished{Jacobson93
@@ -244,7 +367,13 @@ System Services"
 ,title="Avoid Read-Side Locking Via Delayed Free"
 ,year="1993"
 ,month="September"
-,note="Verbal discussion"
+,note="private communication"
+,annotation={
+	Use fixed time delay to approximate grace period.  Very simple,
+	but subject to random memory corruption under heavy load.
+	.
+	Independent invention of RCU-like mechanism.
+}
 }
 
 @Conference{AjuJohn95
@@ -256,6 +385,17 @@ System Services"
 ,Year="1995"
 ,pages="11-23"
 ,Address="New Orleans, LA"
+,note="Available:
+\url{https://www.usenix.org/publications/library/proceedings/neworl/full_papers/john.a}
+[Viewed October 1, 2010]"
+,annotation={
+	Age vnodes out of the cache, and have a fixed time set by a kernel
+	parameter.  Not clear that all races were in fact correctly handled.
+	Used a 20-minute time by default, which would most definitely not
+	be suitable during DoS attacks or virus scans.
+	.
+	Apparently independent invention of RCU-like mechanism.
+}
 }
 
 @conference{Pu95a,
@@ -301,31 +441,47 @@ Utilizing Execution History and Thread Monitoring"
 ,institution="US Patent and Trademark Office"
 ,address="Washington, DC"
 ,year="1995"
-,number="US Patent 5,442,758 (contributed under GPL)"
+,number="US Patent 5,442,758"
 ,month="August"
+,annotation={
+	Describes the parallel RCU infrastructure.  Includes NUMA aspect
+	(structure of bitmap can reflect bus structure of computer system).
+	.
+	Another independent invention of an RCU-like mechanism, but the
+	"real" RCU this time!
+}
 }
 
 @techreport{Slingwine97
 ,author="John D. Slingwine and Paul E. McKenney"
-,title="Method for maintaining data coherency using thread
-activity summaries in a multicomputer system"
+,title="Method for Maintaining Data Coherency Using Thread Activity
+Summaries in a Multicomputer System"
 ,institution="US Patent and Trademark Office"
 ,address="Washington, DC"
 ,year="1997"
-,number="US Patent 5,608,893 (contributed under GPL)"
+,number="US Patent 5,608,893"
 ,month="March"
+,pages="19"
+,annotation={
+	Describes use of RCU to synchronize data between a pair of
+	SMP/NUMA computer systems.
+}
 }
 
 @techreport{Slingwine98
 ,author="John D. Slingwine and Paul E. McKenney"
-,title="Apparatus and method for achieving reduced overhead
-mutual exclusion and maintaining coherency in a multiprocessor
-system utilizing execution history and thread monitoring"
+,title="Apparatus and Method for Achieving Reduced Overhead Mutual
+Exclusion and Maintaining Coherency in a Multiprocessor System
+Utilizing Execution History and Thread Monitoring"
 ,institution="US Patent and Trademark Office"
 ,address="Washington, DC"
 ,year="1998"
-,number="US Patent 5,727,209 (contributed under GPL)"
+,number="US Patent 5,727,209"
 ,month="March"
+,annotation={
+	Describes doing an atomic update by copying the data item and
+	then substituting it into the data structure.
+}
 }
 
 @Conference{McKenney98
@@ -337,6 +493,15 @@ Problems"
 ,Year="1998"
 ,pages="509-518"
 ,Address="Las Vegas, NV"
+,note="Available:
+\url{http://www.rdrop.com/users/paulmck/RCU/rclockpdcsproof.pdf}
+[Viewed December 3, 2007]"
+,annotation={
+	Describes and analyzes RCU mechanism in DYNIX/ptx.  Describes
+	application to linked list update and log-buffer flushing.
+	Defines 'quiescent state'.  Includes both measured and analytic
+	evaluation.
+}
 }
 
 @Conference{Gamsa99
@@ -349,18 +514,76 @@ Operating System Design and Implementation}"
 ,Year="1999"
 ,pages="87-100"
 ,Address="New Orleans, LA"
+,note="Available:
+\url{http://www.usenix.org/events/osdi99/full_papers/gamsa/gamsa.pdf}
+[Viewed August 30, 2006]"
+,annotation={
+	Use of RCU-like facility in K42/Tornado.  Another independent
+	invention of RCU.
+	See especially pages 7-9 (Section 5).
+}
+}
+
+@unpublished{RustyRussell2000a
+,Author="Rusty Russell"
+,Title="Re: modular net drivers"
+,month="June"
+,year="2000"
+,day="23"
+,note="Available:
+\url{http://oss.sgi.com/projects/netdev/archive/2000-06/msg00250.html}
+[Viewed April 10, 2006]"
+,annotation={
+	Proto-RCU proposal from Phil Rumpf and Rusty Russell.
+	Yet another independent invention of RCU.
+	Outline of algorithm to unload modules...
+	.
+	Appeared on net-dev mailing list.
+}
+}
+
+@unpublished{RustyRussell2000b
+,Author="Rusty Russell"
+,Title="Re: modular net drivers"
+,month="June"
+,year="2000"
+,day="24"
+,note="Available:
+\url{http://oss.sgi.com/projects/netdev/archive/2000-06/msg00254.html}
+[Viewed April 10, 2006]"
+,annotation={
+	Proto-RCU proposal from Phil Rumpf and Rusty Russell.
+	.
+	Appeared on net-dev mailing list.
+}
+}
+
+@unpublished{McKenney01b
+,Author="Paul E. McKenney and Dipankar Sarma"
+,Title="Read-Copy Update Mutual Exclusion in {Linux}"
+,month="February"
+,year="2001"
+,note="Available:
+\url{http://lse.sourceforge.net/locking/rcu/rcupdate_doc.html}
+[Viewed October 18, 2004]"
+,annotation={
+	Prototypical Linux documentation for RCU.
+}
 }
 
 @techreport{Slingwine01
 ,author="John D. Slingwine and Paul E. McKenney"
-,title="Apparatus and method for achieving reduced overhead
-mutual exclusion and maintaining coherency in a multiprocessor
-system utilizing execution history and thread monitoring"
+,title="Apparatus and Method for Achieving Reduced Overhead Mutual
+Exclusion and Maintaining Coherency in a Multiprocessor System
+Utilizing Execution History and Thread Monitoring"
 ,institution="US Patent and Trademark Office"
 ,address="Washington, DC"
 ,year="2001"
-,number="US Patent 5,219,690 (contributed under GPL)"
+,number="US Patent 6,219,690"
 ,month="April"
+,annotation={
+	'Change in mode' aspect of RCU.  Can be thought of as a lazy barrier.
+}
 }
 
 @Conference{McKenney01a
@@ -372,14 +595,61 @@ Orran Krieger and Rusty Russell and Dipankar Sarma and Maneesh Soni"
 ,Year="2001"
 ,note="Available:
 \url{http://www.linuxsymposium.org/2001/abstracts/readcopy.php}
-\url{http://www.rdrop.com/users/paulmck/rclock/rclock_OLS.2001.05.01c.pdf}
+\url{http://www.rdrop.com/users/paulmck/RCU/rclock_OLS.2001.05.01c.pdf}
 [Viewed June 23, 2004]"
-annotation="
-Described RCU, and presented some patches implementing and using it in
-the Linux kernel.
+,annotation={
+	Described RCU, and presented some patches implementing and using
+	it in the Linux kernel.
+}
+}
+
+@unpublished{McKenney01f
+,Author="Paul E. McKenney"
+,Title="{RFC:} patch to allow lock-free traversal of lists with insertion"
+,month="October"
+,year="2001"
+,note="Available:
+\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=100259266316456&w=2}
+[Viewed June 23, 2004]"
+,annotation="
+	Memory-barrier and Alpha thread.  100 messages, not too bad...
+"
+}
+
+@unpublished{Spraul01
+,Author="Manfred Spraul"
+,Title="Re: {RFC:} patch to allow lock-free traversal of lists with insertion"
+,month="October"
+,year="2001"
+,note="Available:
+\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=100264675012867&w=2}
+[Viewed June 23, 2004]"
+,annotation="
+	Suggested burying memory barriers in Linux's list-manipulation
+	primitives.
 "
 }
 
+@unpublished{LinusTorvalds2001a
+,Author="Linus Torvalds"
+,Title="{Re:} {[Lse-tech]} {Re:} {RFC:} patch to allow lock-free traversal of lists with insertion"
+,month="October"
+,year="2001"
+,note="Available:
+\url{http://lkml.org/lkml/2001/10/13/105}
+[Viewed August 21, 2004]"
+}
+
+@unpublished{Blanchard02a
+,Author="Anton Blanchard"
+,Title="some RCU dcache and ratcache results"
+,month="March"
+,year="2002"
+,note="Available:
+\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=101637107412972&w=2}
+[Viewed October 18, 2004]"
+}
+
 @Conference{Linder02a
 ,Author="Hanna Linder and Dipankar Sarma and Maneesh Soni"
 ,Title="Scalability of the Directory Entry Cache"
@@ -387,6 +657,10 @@ the Linux kernel.
 ,Month="June"
 ,Year="2002"
 ,pages="289-300"
+,annotation="
+	Measured scalability of Linux 2.4 kernel's directory-entry cache
+	(dcache), and measured some scalability enhancements.
+"
 }
 
 @Conference{McKenney02a
@@ -400,49 +674,76 @@ Andrea Arcangeli and Andi Kleen and Orran Krieger and Rusty Russell"
 ,note="Available:
 \url{http://www.linux.org.uk/~ajh/ols2002_proceedings.pdf.gz}
 [Viewed June 23, 2004]"
+,annotation="
+	Presented and compared a number of RCU implementations for the
+	Linux kernel.
+"
 }
 
-@conference{Michael02a
-,author="Maged M. Michael"
-,title="Safe Memory Reclamation for Dynamic Lock-Free Objects Using Atomic
-Reads and Writes"
-,Year="2002"
-,Month="August"
-,booktitle="{Proceedings of the 21\textsuperscript{st} Annual ACM
-Symposium on Principles of Distributed Computing}"
-,pages="21-30"
+@unpublished{Sarma02a
+,Author="Dipankar Sarma"
+,Title="specweb99: dcache scalability results"
+,month="July"
+,year="2002"
+,note="Available:
+\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=102645767914212&w=2}
+[Viewed June 23, 2004]"
 ,annotation="
-	Each thread keeps an array of pointers to items that it is
-	currently referencing.	Sort of an inside-out garbage collection
-	mechanism, but one that requires the accessing code to explicitly
-	state its needs.  Also requires read-side memory barriers on
-	most architectures.
+	Compare fastwalk and RCU for dcache.  RCU won.
 "
 }
 
-@conference{Michael02b
-,author="Maged M. Michael"
-,title="High Performance Dynamic Lock-Free Hash Tables and List-Based Sets"
-,Year="2002"
-,Month="August"
-,booktitle="{Proceedings of the 14\textsuperscript{th} Annual ACM
-Symposium on Parallel
-Algorithms and Architecture}"
-,pages="73-82"
+@unpublished{Barbieri02
+,Author="Luca Barbieri"
+,Title="Re: {[PATCH]} Initial support for struct {vfs\_cred}"
+,month="August"
+,year="2002"
+,note="Available:
+\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=103082050621241&w=2}
+[Viewed: June 23, 2004]"
 ,annotation="
-	Like the title says...
+	Suggested RCU for vfs\_shared\_cred.
 "
 }
 
-@InProceedings{HerlihyLM02
-,author={Maurice Herlihy and Victor Luchangco and Mark Moir}
-,title="The Repeat Offender Problem: A Mechanism for Supporting Dynamic-Sized,
-Lock-Free Data Structures"
-,booktitle={Proceedings of 16\textsuperscript{th} International
-Symposium on Distributed Computing}
-,year=2002
+@unpublished{Dickins02a
+,author="Hugh Dickins"
+,title="Use RCU for System-V IPC"
+,year="2002"
+,month="October"
+,note="private communication"
+}
+
+@unpublished{Sarma02b
+,Author="Dipankar Sarma"
+,Title="Some dcache\_rcu benchmark numbers"
 ,month="October"
-,pages="339-353"
+,year="2002"
+,note="Available:
+\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=103462075416638&w=2}
+[Viewed June 23, 2004]"
+,annotation="
+	Performance of dcache RCU on kernbench for 16x NUMA-Q and 1x,
+	2x, and 4x systems.  RCU does no harm, and helps on 16x.
+"
+}
+
+@unpublished{LinusTorvalds2003a
+,Author="Linus Torvalds"
+,Title="Re: {[PATCH]} small fixes in brlock.h"
+,month="March"
+,year="2003"
+,note="Available:
+\url{http://lkml.org/lkml/2003/3/9/205}
+[Viewed March 13, 2006]"
+,annotation="
+	Linus suggests replacing brlock with RCU and/or seqlocks:
+	.
+	'It's entirely possible that the current user could be replaced
+	by RCU and/or seqlocks, and we could get rid of brlocks entirely.'
+	.
+	Steve Hemminger responds by replacing them with RCU.
+"
 }
 
 @article{Appavoo03a
@@ -457,6 +758,20 @@ B. Rosenburg and M. Stumm and J. Xenidis"
 ,volume="42"
 ,number="1"
 ,pages="60-76"
+,annotation="
+	Use of RCU to enable hot-swapping for autonomic behavior in K42.
+"
+}
+
+@unpublished{Seigh03
+,author="Joseph W. {Seigh II}"
+,title="Read Copy Update"
+,Year="2003"
+,Month="March"
+,note="email correspondence"
+,annotation="
+	Described the relationship of the VM/XA passive serialization to RCU.
+"