summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/RCU/RTFP.txt4
-rw-r--r--Documentation/RCU/rcuref.txt9
-rw-r--r--Documentation/kernel-parameters.txt7
-rw-r--r--Documentation/memory-barriers.txt27
-rw-r--r--MAINTAINERS18
-rw-r--r--init/Kconfig4
-rw-r--r--kernel/rcu/tree.h28
-rw-r--r--kernel/rcu/tree_plugin.h255
-rw-r--r--kernel/torture.c2
-rwxr-xr-xscripts/get_maintainer.pl22
-rwxr-xr-xtools/testing/selftests/rcutorture/bin/kvm-recheck.sh8
-rwxr-xr-xtools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh9
-rw-r--r--tools/testing/selftests/rcutorture/bin/kvm.sh21
13 files changed, 346 insertions, 68 deletions
diff --git a/Documentation/RCU/RTFP.txt b/Documentation/RCU/RTFP.txt
index 2f0fcb2..f29bcbc 100644
--- a/Documentation/RCU/RTFP.txt
+++ b/Documentation/RCU/RTFP.txt
@@ -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.
diff --git a/Documentation/RCU/rcuref.txt b/Documentation/RCU/rcuref.txt
index 141d531..613033f 100644
--- a/Documentation/RCU/rcuref.txt
+++ b/Documentation/RCU/rcuref.txt
@@ -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:
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 910c382..770662c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2802,6 +2802,13 @@ 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.
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index f1dc4a2..a4de88f 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -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();
diff --git a/MAINTAINERS b/MAINTAINERS
index 134483f..4619a91 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -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
@@ -7399,10 +7401,14 @@ L: linux-kernel@vger.kernel.org
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" <paulmck@linux.vnet.ibm.com>
+M: Josh Triplett <josh@joshtriplett.org>
+R: Steven Rostedt <rostedt@goodmis.org>
+R: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+R: Lai Jiangshan <laijs@cn.fujitsu.com>
L: linux-kernel@vger.kernel.org
S: Supported
T: git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
@@ -7425,8 +7431,11 @@ S: Supported
F: net/rds/
READ-COPY UPDATE (RCU)
-M: Dipankar Sarma <dipankar@in.ibm.com>
M: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
+M: Josh Triplett <josh@joshtriplett.org>
+R: Steven Rostedt <rostedt@goodmis.org>
+R: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+R: Lai Jiangshan <laijs@cn.fujitsu.com>
L: linux-kernel@vger.kernel.org
W: http://www.rdrop.com/users/paulmck/RCU/
S: Supported
@@ -7436,7 +7445,7 @@ 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 <a.zummo@towertech.it>
@@ -8206,6 +8215,9 @@ F: mm/sl?b.c
SLEEPABLE READ-COPY UPDATE (SRCU)
M: Lai Jiangshan <laijs@cn.fujitsu.com>
M: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
+M: Josh Triplett <josh@joshtriplett.org>
+R: Steven Rostedt <rostedt@goodmis.org>
+R: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
L: linux-kernel@vger.kernel.org
W: http://www.rdrop.com/users/paulmck/RCU/
S: Supported
diff --git a/init/Kconfig b/init/Kconfig
index 977b378..41066e4 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -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
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 60fb0ea..71e64c7 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -342,11 +342,29 @@ struct rcu_data {
struct rcu_head **nocb_tail;
atomic_long_t nocb_q_count; /* # CBs waiting for kthread */
atomic_long_t nocb_q_count_lazy; /* (approximate). */
+ struct rcu_head *nocb_follower_head; /* CBs ready to invoke. */
+ struct rcu_head **nocb_follower_tail;
+ atomic_long_t nocb_follower_count; /* # CBs ready to invoke. */
+ atomic_long_t nocb_follower_count_lazy; /* (approximate). */
int nocb_p_count; /* # CBs being invoked by kthread */
int nocb_p_count_lazy; /* (approximate). */
wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */
struct task_struct *nocb_kthread;
bool nocb_defer_wakeup; /* Defer wakeup of nocb_kthread. */
+
+ /* The following fields are used by the leader, hence own cacheline. */
+ struct rcu_head *nocb_gp_head ____cacheline_internodealigned_in_smp;
+ /* CBs waiting for GP. */
+ struct rcu_head **nocb_gp_tail;
+ long nocb_gp_count;
+ long nocb_gp_count_lazy;
+ bool nocb_leader_wake; /* Is the nocb leader thread awake? */
+ struct rcu_data *nocb_next_follower;
+ /* Next follower in wakeup chain. */
+
+ /* The following fields are used by the follower, hence new cachline. */
+ struct rcu_data *nocb_leader ____cacheline_internodealigned_in_smp;
+ /* Leader CPU takes GP-end wakeups. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
/* 8) RCU CPU stall data. */
@@ -595,8 +613,14 @@ static bool rcu_nohz_full_cpu(struct rcu_state *rsp);
/* Sum up queue lengths for tracing. */
static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
{
- *ql = atomic_long_read(&rdp->nocb_q_count) + rdp->nocb_p_count;
- *qll = atomic_long_read(&rdp->nocb_q_count_lazy) + rdp->nocb_p_count_lazy;
+ *ql = atomic_long_read(&rdp->nocb_q_count) +
+ rdp->nocb_p_count +
+ atomic_long_read(&rdp->nocb_follower_count) +
+ rdp->nocb_p_count + rdp->nocb_gp_count;
+ *qll = atomic_long_read(&rdp->nocb_q_count_lazy) +
+ rdp->nocb_p_count_lazy +
+ atomic_long_read(&rdp->nocb_follower_count_lazy) +
+ rdp->nocb_p_count_lazy + rdp->nocb_gp_count_lazy;
}
#else /* #ifdef CONFIG_RCU_NOCB_CPU */
static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index c66bdcb..f62b7f2 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2066,6 +2066,22 @@ bool rcu_is_nocb_cpu(int cpu)
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
/*
+ * Kick the leader kthread for this NOCB group.
+ */
+static void wake_nocb_leader(struct rcu_data *rdp, bool force)
+{
+ struct rcu_data *rdp_leader = rdp->nocb_leader;
+
+ if (!ACCESS_ONCE(rdp_leader->nocb_kthread))
+ return;
+ if (!ACCESS_ONCE(rdp_leader->nocb_leader_wake) || force) {
+ /* Prior xchg orders against prior callback enqueue. */
+ ACCESS_ONCE(rdp_leader->nocb_leader_wake) = true;
+ wake_up(&rdp_leader->nocb_wq);
+ }
+}
+
+/*
* Enqueue the specified string of rcu_head structures onto the specified
* CPU's no-CBs lists. The CPU is specified by rdp, the head of the
* string by rhp, and the tail of the string by rhtp. The non-lazy/lazy
@@ -2099,7 +2115,8 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
len = atomic_long_read(&rdp->nocb_q_count);
if (old_rhpp == &rdp->nocb_head) {
if (!irqs_disabled_flags(flags)) {
- wake_up(&rdp->nocb_wq); /* ... if queue was empty ... */
+ /* ... if queue was empty ... */
+ wake_nocb_leader(rdp, false);
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
TPS("WakeEmpty"));
} else {
@@ -2109,7 +2126,8 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
}
rdp->qlen_last_fqs_check = 0;
} else if (len > rdp->qlen_last_fqs_check + qhimark) {
- wake_up_process(t); /* ... or if many callbacks queued. */
+ /* ... or if many callbacks queued. */
+ wake_nocb_leader(rdp, true);
rdp->qlen_last_fqs_check = LONG_MAX / 2;
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("WakeOvf"));
} else {
@@ -2219,13 +2237,150 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
}
/*
+ * Leaders come here to wait for additional callbacks to show up.
+ * This function does not return until callbacks appear.
+ */
+static void nocb_leader_wait(struct rcu_data *my_rdp)
+{
+ bool firsttime = true;
+ bool gotcbs;
+ struct rcu_data *rdp;
+ struct rcu_head **tail;
+
+wait_again:
+
+ /* Wait for callbacks to appear. */
+ if (!rcu_nocb_poll) {
+ trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Sleep");
+ wait_event_interruptible(my_rdp->nocb_wq,
+ ACCESS_ONCE(my_rdp->nocb_leader_wake));
+ /* Memory barrier handled by smp_mb() calls below and repoll. */
+ } else if (firsttime) {
+ firsttime = false; /* Don't drown trace log with "Poll"! */
+ trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Poll");
+ }
+
+ /*
+ * Each pass through the following loop checks a follower for CBs.
+ * We are our own first follower. Any CBs found are moved to
+ * nocb_gp_head, where they await a grace period.
+ */
+ gotcbs = false;
+ for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower) {
+ rdp->nocb_gp_head = ACCESS_ONCE(rdp->nocb_head);
+ if (!rdp->nocb_gp_head)
+ continue; /* No CBs here, try next follower. */
+
+ /* Move callbacks to wait-for-GP list, which is empty. */
+ ACCESS_ONCE(rdp->nocb_head) = NULL;
+ rdp->nocb_gp_tail = xchg(&rdp->nocb_tail, &rdp->nocb_head);
+ rdp->nocb_gp_count = atomic_long_xchg(&rdp->nocb_q_count, 0);
+ rdp->nocb_gp_count_lazy =
+ atomic_long_xchg(&rdp->nocb_q_count_lazy, 0);
+ gotcbs = true;
+ }
+
+ /*
+ * If there were no callbacks, sleep a bit, rescan after a
+ * memory barrier, and go retry.
+ */
+ if (unlikely(!gotcbs)) {
+ if (!rcu_nocb_poll)
+ trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu,
+ "WokeEmpty");
+ flush_signals(current);
+ schedule_timeout_interruptible(1);
+
+ /* Rescan in case we were a victim of memory ordering. */
+ my_rdp->nocb_leader_wake = false;
+ smp_mb(); /* Ensure _wake false before scan. */
+ for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower)
+ if (ACCESS_ONCE(rdp->nocb_head)) {
+ /* Found CB, so short-circuit next wait. */
+ my_rdp->nocb_leader_wake = true;
+ break;
+ }
+ goto wait_again;
+ }
+
+ /* Wait for one grace period. */
+ rcu_nocb_wait_gp(my_rdp);
+
+ /*
+ * We left ->nocb_leader_wake set to reduce cache thrashing.
+ * We clear it now, but recheck for new callbacks while
+ * traversing our follower list.
+ */
+ my_rdp->nocb_leader_wake = false;
+ smp_mb(); /* Ensure _wake false before scan of ->nocb_head. */
+
+ /* Each pass through the following loop wakes a follower, if needed. */
+ for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower) {
+ if (ACCESS_ONCE(rdp->nocb_head))
+ my_rdp->nocb_leader_wake = true; /* No need to wait. */
+ if (!rdp->nocb_gp_head)
+ continue; /* No CBs, so no need to wake follower. */
+
+ /* Append callbacks to follower's "done" list. */
+ tail = xchg(&rdp->nocb_follower_tail, rdp->nocb_gp_tail);
+ *tail = rdp->nocb_gp_head;
+ atomic_long_add(rdp->nocb_gp_count, &rdp->nocb_follower_count);
+ atomic_long_add(rdp->nocb_gp_count_lazy,
+ &rdp->nocb_follower_count_lazy);
+ if (rdp != my_rdp && tail == &rdp->nocb_follower_head) {
+ /*
+ * List was empty, wake up the follower.
+ * Memory barriers supplied by atomic_long_add().
+ */
+ wake_up(&rdp->nocb_wq);
+ }
+ }
+
+ /* If we (the leader) don't have CBs, go wait some more. */
+ if (!my_rdp->nocb_follower_head)
+ goto wait_again;
+}
+
+/*
+ * Followers come here to wait for additional callbacks to show up.
+ * This function does not return until callbacks appear.
+ */
+static void nocb_follower_wait(struct rcu_data *rdp)
+{
+ bool firsttime = true;
+
+ for (;;) {
+ if (!rcu_nocb_poll) {
+ trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+ "FollowerSleep");
+ wait_event_interruptible(rdp->nocb_wq,
+ ACCESS_ONCE(rdp->nocb_follower_head));
+ } else if (firsttime) {
+ /* Don't drown trace log with "Poll"! */
+ firsttime = false;
+ trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, "Poll");
+ }
+ if (smp_load_acquire(&rdp->nocb_follower_head)) {
+ /* ^^^ Ensure CB invocation follows _head test. */
+ return;
+ }
+ if (!rcu_nocb_poll)
+ trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
+ "WokeEmpty");
+ flush_signals(current);
+ schedule_timeout_interruptible(1);
+ }
+}
+
+/*
* Per-rcu_data kthread, but only for no-CBs CPUs. Each kthread invokes
- * callbacks queued by the corresponding no-CBs CPU.
+ * callbacks queued by the corresponding no-CBs CPU, however, there is
+ * an optional leader-follower relationship so that the grace-period
+ * kthreads don't have to do quite so many wakeups.
*/
static int rcu_nocb_kthread(void *arg)
{
int c, cl;
- bool firsttime = 1;
struct rcu_head *list;
struct rcu_head *next;
struct rcu_head **tail;
@@ -2233,41 +2388,22 @@ static int rcu_nocb_kthread(void *arg)
/* Each pass through this loop invokes one batch of callbacks */
for (;;) {
- /* If not polling, wait for next batch of callbacks. */
- if (!rcu_nocb_poll) {
- trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
- TPS("Sleep"));
- wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
- /* Memory barrier provide by xchg() below. */
- } else if (firsttime) {
- firsttime = 0;
- trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
- TPS("Poll"));
- }
- list = ACCESS_ONCE(rdp->nocb_head);
- if (!list) {
- if (!rcu_nocb_poll)
- trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
- TPS("WokeEmpty"));
- schedule_timeout_interruptible(1);
- flush_signals(current);
- continue;
- }
- firsttime = 1;
- trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
- TPS("WokeNonEmpty"));
-
- /*
- * Extract queued callbacks, update counts, and wait
- * for a grace period to elapse.
- */
- ACCESS_ONCE(rdp->nocb_head) = NULL;
- tail = xchg(&rdp->nocb_tail, &rdp->nocb_head);
- c = atomic_long_xchg(&rdp->nocb_q_count, 0);
- cl = atomic_long_xchg(&rdp->nocb_q_count_lazy, 0);
- ACCESS_ONCE(rdp->nocb_p_count) += c;
- ACCESS_ONCE(rdp->nocb_p_count_lazy) += cl;
- rcu_nocb_wait_gp(rdp);
+ /* Wait for callbacks. */
+ if (rdp->nocb_leader == rdp)
+ nocb_leader_wait(rdp);
+ else
+ nocb_follower_wait(rdp);
+
+ /* Pull the ready-to-invoke callbacks onto local list. */
+ list = ACCESS_ONCE(rdp->nocb_follower_head);
+ BUG_ON(!list);
+ trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, "WokeNonEmpty");
+ ACCESS_ONCE(rdp->nocb_follower_head) = NULL;
+ tail = xchg(&rdp->nocb_follower_tail, &rdp->nocb_follower_head);
+ c = atomic_long_xchg(&rdp->nocb_follower_count, 0);
+ cl = atomic_long_xchg(&rdp->nocb_follower_count_lazy, 0);
+ rdp->nocb_p_count += c;
+ rdp->nocb_p_count_lazy += cl;
/* Each pass through the following loop invokes a callback. */
trace_rcu_batch_start(rdp->rsp->name, cl, c, -1);
@@ -2311,7 +2447,7 @@ static void do_nocb_deferred_wakeup(struct rcu_data *rdp)
if (!rcu_nocb_need_deferred_wakeup(rdp))
return;
ACCESS_ONCE(rdp->nocb_defer_wakeup) = false;
- wake_up(&rdp->nocb_wq);
+ wake_nocb_leader(rdp, false);
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("DeferredWakeEmpty"));
}
@@ -2320,19 +2456,56 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
{
rdp->nocb_tail = &rdp->nocb_head;
init_waitqueue_head(&rdp->nocb_wq);
+ rdp->nocb_follower_tail = &rdp->nocb_follower_head;
}
-/* Create a kthread for each RCU flavor for each no-CBs CPU. */
+/* How many follower CPU IDs per leader? Default of -1 for sqrt(nr_cpu_ids). */
+static int rcu_nocb_leader_stride = -1;
+module_param(rcu_nocb_leader_stride, int, 0444);
+
+/*
+ * Create a kthread for each RCU flavor for each no-CBs CPU.
+ * Also initialize leader-follower relationships.
+ */
static void __init rcu_spawn_nocb_kthreads(struct rcu_state *rsp)
{
int cpu;
+ int ls = rcu_nocb_leader_stride;
+ int nl = 0; /* Next leader. */
struct rcu_data *rdp;
+ struct rcu_data *rdp_leader = NULL; /* Suppress misguided gcc warn. */
+ struct rcu_data *rdp_prev = NULL;
struct task_struct *t;
if (rcu_nocb_mask == NULL)
return;
+#ifdef CONFIG_NO_HZ_FULL
+ cpumask_or(rcu_nocb_mask, rcu_nocb_mask, tick_nohz_full_mask);
+#endif /* #ifdef CONFIG_NO_HZ_FULL */
+ if (ls == -1) {
+ ls = int_sqrt(nr_cpu_ids);
+ rcu_nocb_leader_stride = ls;
+ }
+
+ /*
+ * Each pass through this loop sets up one rcu_data structure and
+ * spawns one rcu_nocb_kthread().
+ */
for_each_cpu(cpu, rcu_nocb_mask) {
rdp = per_cpu_ptr(rsp->rda, cpu);
+ if (rdp->cpu >= nl) {
+ /* New leader, set up for followers & next leader. */
+ nl = DIV_ROUND_UP(rdp->cpu + 1, ls) * ls;
+ rdp->nocb_leader = rdp;
+ rdp_leader = rdp;
+ } else {
+ /* Another follower, link to previous leader. */
+ rdp->nocb_leader = rdp_leader;
+ rdp_prev->nocb_next_follower = rdp;
+ }
+ rdp_prev = rdp;
+
+ /* Spawn the kthread for this CPU. */
t = kthread_run(rcu_nocb_kthread, rdp,
"rcuo%c/%d", rsp->abbr, cpu);
BUG_ON(IS_ERR(t));
diff --git a/kernel/torture.c b/kernel/torture.c
index 40bb511..d600af21 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -708,7 +708,7 @@ int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
int ret = 0;
VERBOSE_TOROUT_STRING(m);
- *tp = kthread_run(fn, arg, s);
+ *tp = kthread_run(fn, arg, "%s", s);
if (IS_ERR(*tp)) {
ret = PTR_ERR(*tp);
VERBOSE_TOROUT_ERRSTRING(f);
diff --git a/scripts/get_maintainer.pl b/scripts/get_maintainer.pl
index 4198788..d701627 100755
--- a/scripts/get_maintainer.pl
+++ b/scripts/get_maintainer.pl
@@ -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") {
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index ee1f6ca..3f6c9b7 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -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
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
index 27e544e..0f69dcb 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -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
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 40285c5..589e9c3 100644
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -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
OpenPOWER on IntegriCloud