RCU changes for v3.17

index 2f0fcb2..f29bcbc 100644
@@ -2451,8 +2451,8 @@ lot of {Linux} into your technology!!!"
 ,month="February"
 ,year="2010"
 ,note="Available:
-\url{http://kerneltrap.com/mailarchive/linux-netdev/2010/2/26/6270589}
-[Viewed March 20, 2011]"
+\url{http://thread.gmane.org/gmane.linux.network/153338}
+[Viewed June 9, 2014]"
 ,annotation={
 	Use a pair of list_head structures to support RCU-protected
 	resizable hash tables.

index 141d531..613033f 100644
@@ -1,5 +1,14 @@
 Reference-count design for elements of lists/arrays protected by RCU.
 
+
+Please note that the percpu-ref feature is likely your first
+stop if you need to combine reference counts and RCU.  Please see
+include/linux/percpu-refcount.h for more information.  However, in
+those unusual cases where percpu-ref would consume too much memory,
+please read on.
+
+------------------------------------------------------------------------
+
 Reference counting on elements of lists which are protected by traditional
 reader/writer spinlocks or semaphores are straightforward:
 

index c1b9aa8..6439c93 100644
@@ -2790,6 +2790,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			leaf rcu_node structure.  Useful for very large
 			systems.
 
+	rcutree.jiffies_till_sched_qs= [KNL]
+			Set required age in jiffies for a
+			given grace period before RCU starts
+			soliciting quiescent-state help from
+			rcu_note_context_switch().
+
 	rcutree.jiffies_till_first_fqs= [KNL]
 			Set delay from grace-period initialization to
 			first attempt to force quiescent states.

@@ -2801,6 +2807,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			quiescent states.  Units are jiffies, minimum
 			value is one, and maximum value is HZ.
 
+	rcutree.rcu_nocb_leader_stride= [KNL]
+			Set the number of NOCB kthread groups, which
+			defaults to the square root of the number of
+			CPUs.  Larger numbers reduces the wakeup overhead
+			on the per-CPU grace-period kthreads, but increases
+			that same overhead on each group's leader.
+
 	rcutree.qhimark= [KNL]
 			Set threshold of queued RCU callbacks beyond which
 			batch limiting is disabled.

index f1dc4a2..a4de88f 100644
@@ -757,10 +757,14 @@ SMP BARRIER PAIRING
 When dealing with CPU-CPU interactions, certain types of memory barrier should
 always be paired.  A lack of appropriate pairing is almost certainly an error.
 
-A write barrier should always be paired with a data dependency barrier or read
-barrier, though a general barrier would also be viable.  Similarly a read
-barrier or a data dependency barrier should always be paired with at least an
-write barrier, though, again, a general barrier is viable:
+General barriers pair with each other, though they also pair with
+most other types of barriers, albeit without transitivity.  An acquire
+barrier pairs with a release barrier, but both may also pair with other
+barriers, including of course general barriers.  A write barrier pairs
+with a data dependency barrier, an acquire barrier, a release barrier,
+a read barrier, or a general barrier.  Similarly a read barrier or a
+data dependency barrier pairs with a write barrier, an acquire barrier,
+a release barrier, or a general barrier:
 
 	CPU 1		      CPU 2
 	===============	      ===============

@@ -1893,6 +1897,21 @@ between the STORE to indicate the event and the STORE to set TASK_RUNNING:
 	    <general barrier>		  STORE current->state
 	LOAD event_indicated
 
+To repeat, this write memory barrier is present if and only if something
+is actually awakened.  To see this, consider the following sequence of
+events, where X and Y are both initially zero:
+
+	CPU 1				CPU 2
+	===============================	===============================
+	X = 1;				STORE event_indicated
+	smp_mb();			wake_up();
+	Y = 1;				wait_event(wq, Y == 1);
+	wake_up();			  load from Y sees 1, no memory barrier
+					load from X might see 0
+
+In contrast, if a wakeup does occur, CPU 2's load from X would be guaranteed
+to see 1.
+
 The available waker functions include:
 
 	complete();

index e31c874..6b829e6 100644
@@ -70,6 +70,8 @@ Descriptions of section entries:
 
 	P: Person (obsolete)
 	M: Mail patches to: FullName <address@domain>
+	R: Designated reviewer: FullName <address@domain>
+	   These reviewers should be CCed on patches.
 	L: Mailing list that is relevant to this area
 	W: Web-page with status/info
 	Q: Patchwork web based patch tracking system site

@@ -7426,10 +7428,14 @@ L:	[email protected]
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
 F:	Documentation/RCU/torture.txt
-F:	kernel/rcu/torture.c
+F:	kernel/rcu/rcutorture.c
 
 RCUTORTURE TEST FRAMEWORK
 M:	"Paul E. McKenney" <[email protected]>
+M:	Josh Triplett <[email protected]>
+R:	Steven Rostedt <[email protected]>
+R:	Mathieu Desnoyers <[email protected]>
+R:	Lai Jiangshan <[email protected]>
 L:	[email protected]
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git

@@ -7452,8 +7458,11 @@ S:	Supported
 F:	net/rds/
 
 READ-COPY UPDATE (RCU)
-M:	Dipankar Sarma <[email protected]>
 M:	"Paul E. McKenney" <[email protected]>
+M:	Josh Triplett <[email protected]>
+R:	Steven Rostedt <[email protected]>
+R:	Mathieu Desnoyers <[email protected]>
+R:	Lai Jiangshan <[email protected]>
 L:	[email protected]
 W:	http://www.rdrop.com/users/paulmck/RCU/
 S:	Supported

@@ -7463,7 +7472,7 @@ X:	Documentation/RCU/torture.txt
 F:	include/linux/rcu*
 X:	include/linux/srcu.h
 F:	kernel/rcu/
-X:	kernel/rcu/torture.c
+X:	kernel/torture.c
 
 REAL TIME CLOCK (RTC) SUBSYSTEM
 M:	Alessandro Zummo <[email protected]>

@@ -8236,6 +8245,9 @@ F:	mm/sl?b*
 SLEEPABLE READ-COPY UPDATE (SRCU)
 M:	Lai Jiangshan <[email protected]>
 M:	"Paul E. McKenney" <[email protected]>
+M:	Josh Triplett <[email protected]>
+R:	Steven Rostedt <[email protected]>
+R:	Mathieu Desnoyers <[email protected]>
 L:	[email protected]
 W:	http://www.rdrop.com/users/paulmck/RCU/
 S:	Supported

index 9d76b99..41066e4 100644
@@ -505,7 +505,7 @@ config PREEMPT_RCU
 	def_bool TREE_PREEMPT_RCU
 	help
 	  This option enables preemptible-RCU code that is common between
-	  the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
+	  TREE_PREEMPT_RCU and, in the old days, TINY_PREEMPT_RCU.
 
 config RCU_STALL_COMMON
 	def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )

@@ -737,7 +737,7 @@ choice
 
 config RCU_NOCB_CPU_NONE
 	bool "No build_forced no-CBs CPUs"
-	depends on RCU_NOCB_CPU && !NO_HZ_FULL
+	depends on RCU_NOCB_CPU && !NO_HZ_FULL_ALL
 	help
 	  This option does not force any of the CPUs to be no-CBs CPUs.
 	  Only CPUs designated by the rcu_nocbs= boot parameter will be

@@ -751,7 +751,7 @@ config RCU_NOCB_CPU_NONE
 
 config RCU_NOCB_CPU_ZERO
 	bool "CPU 0 is a build_forced no-CBs CPU"
-	depends on RCU_NOCB_CPU && !NO_HZ_FULL
+	depends on RCU_NOCB_CPU && !NO_HZ_FULL_ALL
 	help
 	  This option forces CPU 0 to be a no-CBs CPU, so that its RCU
 	  callbacks are invoked by a per-CPU kthread whose name begins

index 7a638aa..12132e4 100644
@@ -1131,20 +1131,6 @@ config PROVE_RCU_REPEATEDLY
 
 	 Say N if you are unsure.
 
-config PROVE_RCU_DELAY
-	bool "RCU debugging: preemptible RCU race provocation"
-	depends on DEBUG_KERNEL && PREEMPT_RCU
-	default n
-	help
-	 There is a class of races that involve an unlikely preemption
-	 of __rcu_read_unlock() just after ->rcu_read_lock_nesting has
-	 been set to INT_MIN.  This feature inserts a delay at that
-	 point to increase the probability of these races.
-
-	 Say Y to increase probability of preemption of __rcu_read_unlock().
-
-	 Say N if you are unsure.
-
 config SPARSE_RCU_POINTER
 	bool "RCU debugging: sparse-based checks for pointer usage"
 	default n

index 4198788..d701627 100755
@@ -21,6 +21,7 @@ my $lk_path = "./";
 my $email = 1;
 my $email_usename = 1;
 my $email_maintainer = 1;
+my $email_reviewer = 1;
 my $email_list = 1;
 my $email_subscriber_list = 0;
 my $email_git_penguin_chiefs = 0;

@@ -202,6 +203,7 @@ if (!GetOptions(
 		'remove-duplicates!' => \$email_remove_duplicates,
 		'mailmap!' => \$email_use_mailmap,
 		'm!' => \$email_maintainer,
+		'r!' => \$email_reviewer,
 		'n!' => \$email_usename,
 		'l!' => \$email_list,
 		's!' => \$email_subscriber_list,

@@ -260,7 +262,8 @@ if ($sections) {
 }
 
 if ($email &&
-    ($email_maintainer + $email_list + $email_subscriber_list +
+    ($email_maintainer + $email_reviewer +
+     $email_list + $email_subscriber_list +
      $email_git + $email_git_penguin_chiefs + $email_git_blame) == 0) {
     die "$P: Please select at least 1 email option\n";
 }

@@ -750,6 +753,7 @@ MAINTAINER field selection options:
     --hg-since => hg history to use (default: $email_hg_since)
     --interactive => display a menu (mostly useful if used with the --git option)
     --m => include maintainer(s) if any
+    --r => include reviewer(s) if any
     --n => include name 'Full Name <addr\@domain.tld>'
     --l => include list(s) if any
     --s => include subscriber only list(s) if any

@@ -1064,6 +1068,22 @@ sub add_categories {
 		    my $role = get_maintainer_role($i);
 		    push_email_addresses($pvalue, $role);
 		}
+	    } elsif ($ptype eq "R") {
+		my ($name, $address) = parse_email($pvalue);
+		if ($name eq "") {
+		    if ($i > 0) {
+			my $tv = $typevalue[$i - 1];
+			if ($tv =~ m/^(\C):\s*(.*)/) {
+			    if ($1 eq "P") {
+				$name = $2;
+				$pvalue = format_email($name, $address, $email_usename);
+			    }
+			}
+		    }
+		}
+		if ($email_reviewer) {
+		    push_email_addresses($pvalue, 'reviewer');
+		}
 	    } elsif ($ptype eq "T") {
 		push(@scm, $pvalue);
 	    } elsif ($ptype eq "W") {

index ee1f6ca..3f6c9b7 100755
@@ -54,10 +54,16 @@ do
 			if test -f "$i/qemu-cmd"
 			then
 				print_bug qemu failed
+				echo "   $i"
+			elif test -f "$i/buildonly"
+			then
+				echo Build-only run, no boot/test
+				configcheck.sh $i/.config $i/ConfigFragment
+				parse-build.sh $i/Make.out $configfile
 			else
 				print_bug Build failed
+				echo "   $i"
 			fi
-			echo "   $i"
 		fi
 	done
 done

index 27e544e..0f69dcb 100755
@@ -42,6 +42,7 @@ grace=120
 
 T=/tmp/kvm-test-1-run.sh.$$
 trap 'rm -rf $T' 0
+touch $T
 
 . $KVM/bin/functions.sh
 . $KVPATH/ver_functions.sh

@@ -131,7 +132,10 @@ boot_args=$6
 
 cd $KVM
 kstarttime=`awk 'BEGIN { print systime() }' < /dev/null`
-echo ' ---' `date`: Starting kernel
+if test -z "$TORTURE_BUILDONLY"
+then
+	echo ' ---' `date`: Starting kernel
+fi
 
 # Generate -smp qemu argument.
 qemu_args="-nographic $qemu_args"

@@ -157,12 +161,13 @@ boot_args="`configfrag_boot_params "$boot_args" "$config_template"`"
 # Generate kernel-version-specific boot parameters
 boot_args="`per_version_boot_params "$boot_args" $builddir/.config $seconds`"
 
-echo $QEMU $qemu_args -m 512 -kernel $builddir/$BOOT_IMAGE -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
 if test -n "$TORTURE_BUILDONLY"
 then
 	echo Build-only run specified, boot/test omitted.
+	touch $resdir/buildonly
 	exit 0
 fi
+echo $QEMU $qemu_args -m 512 -kernel $builddir/$BOOT_IMAGE -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
 ( $QEMU $qemu_args -m 512 -kernel $builddir/$BOOT_IMAGE -append "$qemu_append $boot_args"; echo $? > $resdir/qemu-retval ) &
 qemu_pid=$!
 commandcompleted=0

index 40285c5..589e9c3 100644
@@ -340,12 +340,18 @@ function dump(first, pastlast)
 	for (j = 1; j < jn; j++) {
 		builddir=KVM "/b" j
 		print "rm -f " builddir ".ready"
-		print "echo ----", cfr[j], cpusr[j] ovf ": Starting kernel. `date`";
-		print "echo ----", cfr[j], cpusr[j] ovf ": Starting kernel. `date` >> " rd "/log";
+		print "if test -z \"$TORTURE_BUILDONLY\""
+		print "then"
+		print "\techo ----", cfr[j], cpusr[j] ovf ": Starting kernel. `date`";
+		print "\techo ----", cfr[j], cpusr[j] ovf ": Starting kernel. `date` >> " rd "/log";
+		print "fi"
 	}
 	print "wait"
-	print "echo ---- All kernel runs complete. `date`";
-	print "echo ---- All kernel runs complete. `date` >> " rd "/log";
+	print "if test -z \"$TORTURE_BUILDONLY\""
+	print "then"
+	print "\techo ---- All kernel runs complete. `date`";
+	print "\techo ---- All kernel runs complete. `date` >> " rd "/log";
+	print "fi"
 	for (j = 1; j < jn; j++) {
 		builddir=KVM "/b" j
 		print "echo ----", cfr[j], cpusr[j] ovf ": Build/run results:";

@@ -385,10 +391,7 @@ echo
 echo
 echo " --- `date` Test summary:"
 echo Results directory: $resdir/$ds
-if test -z "$TORTURE_BUILDONLY"
-then
-	kvm-recheck.sh $resdir/$ds
-fi
+kvm-recheck.sh $resdir/$ds
 ___EOF___
 
 if test "$dryrun" = script

@@ -403,7 +406,7 @@ then
 		sed -e 's/:.*$//' -e 's/^echo //'
 	exit 0
 else
-	# Not a dryru, so run the script.
+	# Not a dryrun, so run the script.
 	sh $T/script
 fi
 

index 9c827ec..063b707 100644
@@ -15,7 +15,6 @@ CONFIG_RCU_FANOUT_EXACT=n
 CONFIG_RCU_NOCB_CPU=y
 CONFIG_RCU_NOCB_CPU_ZERO=y
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_RCU_BOOST=n

index 1a777b5..ea119ba 100644
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_EXACT=n
 CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=y
 CONFIG_PROVE_LOCKING=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=y
 CONFIG_RCU_BOOST=n

index 61c8d9c..19cf948 100644
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_EXACT=n
 CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=y
 CONFIG_PROVE_LOCKING=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=y
 CONFIG_RCU_BOOST=n

index c1f111c..f4567fb 100644
@@ -14,7 +14,6 @@ CONFIG_RCU_FANOUT_LEAF=4
 CONFIG_RCU_FANOUT_EXACT=n
 CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_RCU_BOOST=y

index 7dbd27c..0a262fb 100644
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_LEAF=2
 CONFIG_RCU_FANOUT_EXACT=n
 CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=y
 CONFIG_RCU_CPU_STALL_VERBOSE=y
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n

index d0f32e5..3a06b97 100644
@@ -18,7 +18,6 @@ CONFIG_RCU_NOCB_CPU_NONE=y
 CONFIG_DEBUG_LOCK_ALLOC=y
 CONFIG_PROVE_LOCKING=y
 CONFIG_PROVE_RCU=y
-CONFIG_PROVE_RCU_DELAY=y
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n

index 2e477df..8f084cc 100644
@@ -19,7 +19,6 @@ CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=y
 CONFIG_PROVE_LOCKING=y
 CONFIG_PROVE_RCU=y
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=y

index 042f86e..ab62255 100644
@@ -17,7 +17,6 @@ CONFIG_RCU_FANOUT_LEAF=2
 CONFIG_RCU_FANOUT_EXACT=n
 CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=y
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n

index 3438cee..69a2e25 100644
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_LEAF=2
 CONFIG_RCU_NOCB_CPU=y
 CONFIG_RCU_NOCB_CPU_ALL=y
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_RCU_BOOST=n

index bf4523d..a0f32fb 100644
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_LEAF=2
 CONFIG_RCU_NOCB_CPU=y
 CONFIG_RCU_NOCB_CPU_ALL=y
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_RCU_BOOST=n

index 81e4f7c..b7a62a5 100644
@@ -13,7 +13,6 @@ CONFIG_SUSPEND=n
 CONFIG_HIBERNATION=n
 CONFIG_RCU_NOCB_CPU=n
 CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
 CONFIG_RCU_CPU_STALL_INFO=n
 CONFIG_RCU_CPU_STALL_VERBOSE=n
 CONFIG_RCU_BOOST=n

index ef624ce..a55c008 100644
@@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=y
 #CHECK#CONFIG_TREE_PREEMPT_RCU=y
 CONFIG_DEBUG_KERNEL=y
-CONFIG_PROVE_RCU_DELAY=y
 CONFIG_DEBUG_OBJECTS=y
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
 CONFIG_RT_MUTEXES=y

index ef624ce..a55c008 100644
@@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=y
 #CHECK#CONFIG_TREE_PREEMPT_RCU=y
 CONFIG_DEBUG_KERNEL=y
-CONFIG_PROVE_RCU_DELAY=y
 CONFIG_DEBUG_OBJECTS=y
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
 CONFIG_RT_MUTEXES=y

index ef624ce..a55c008 100644
@@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=y
 #CHECK#CONFIG_TREE_PREEMPT_RCU=y
 CONFIG_DEBUG_KERNEL=y
-CONFIG_PROVE_RCU_DELAY=y
 CONFIG_DEBUG_OBJECTS=y
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
 CONFIG_RT_MUTEXES=y

index ef624ce..a55c008 100644
@@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=y
 #CHECK#CONFIG_TREE_PREEMPT_RCU=y
 CONFIG_DEBUG_KERNEL=y
-CONFIG_PROVE_RCU_DELAY=y
 CONFIG_DEBUG_OBJECTS=y
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
 CONFIG_RT_MUTEXES=y

index adbb76c..3e588db 100644
@@ -14,7 +14,6 @@ CONFIG_NO_HZ_FULL_SYSIDLE -- Do one.
 CONFIG_PREEMPT -- Do half.  (First three and #8.)
 CONFIG_PROVE_LOCKING -- Do all but two, covering CONFIG_PROVE_RCU and not.
 CONFIG_PROVE_RCU -- Do all but one under CONFIG_PROVE_LOCKING.
-CONFIG_PROVE_RCU_DELAY -- Do one.
 CONFIG_RCU_BOOST -- one of TREE_PREEMPT_RCU.
 CONFIG_RCU_BOOST_PRIO -- set to 2 for _BOOST testing.
 CONFIG_RCU_CPU_STALL_INFO -- do one with and without _VERBOSE.