[git pull] core kernel fixes

From: Ingo Molnar
Date: Sun Jan 11 2009 - 09:36:39 EST


Linus,

Please pull the latest core-fixes-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core-fixes-for-linus

Thanks,

Ingo

------------------>
Andrew Morton (1):
smp_call_function_single(): be slightly less stupid

David Miller (1):
sparc64: Fix cpumask related build failure

Ingo Molnar (1):
smp_call_function_single(): be slightly less stupid, fix

Paul E. McKenney (1):
rcu: fix bug in rcutorture system-shutdown code


arch/sparc/include/asm/topology_64.h | 4 +
include/linux/smp.h | 13 +---
kernel/Makefile | 6 ++-
kernel/rcutorture.c | 113 ++++++++++++++++++++-------------
kernel/up.c | 20 ++++++
5 files changed, 100 insertions(+), 56 deletions(-)
create mode 100644 kernel/up.c

diff --git a/arch/sparc/include/asm/topology_64.h b/arch/sparc/include/asm/topology_64.h
index b8a65b6..5bc0b8f 100644
--- a/arch/sparc/include/asm/topology_64.h
+++ b/arch/sparc/include/asm/topology_64.h
@@ -47,6 +47,10 @@ static inline int pcibus_to_node(struct pci_bus *pbus)
(pcibus_to_node(bus) == -1 ? \
CPU_MASK_ALL : \
node_to_cpumask(pcibus_to_node(bus)))
+#define cpumask_of_pcibus(bus) \
+ (pcibus_to_node(bus) == -1 ? \
+ CPU_MASK_ALL_PTR : \
+ cpumask_of_node(pcibus_to_node(bus)))

#define SD_NODE_INIT (struct sched_domain) { \
.min_interval = 8, \
diff --git a/include/linux/smp.h b/include/linux/smp.h
index b824669..715196b 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -24,6 +24,9 @@ struct call_single_data {
/* total number of cpus in this system (may exceed NR_CPUS) */
extern unsigned int total_cpus;

+int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
+ int wait);
+
#ifdef CONFIG_SMP

#include <linux/preempt.h>
@@ -79,8 +82,6 @@ smp_call_function_mask(cpumask_t mask, void(*func)(void *info), void *info,
return 0;
}

-int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
- int wait);
void __smp_call_function_single(int cpuid, struct call_single_data *data);

/*
@@ -140,14 +141,6 @@ static inline int up_smp_call_function(void (*func)(void *), void *info)
static inline void smp_send_reschedule(int cpu) { }
#define num_booting_cpus() 1
#define smp_prepare_boot_cpu() do {} while (0)
-#define smp_call_function_single(cpuid, func, info, wait) \
-({ \
- WARN_ON(cpuid != 0); \
- local_irq_disable(); \
- (func)(info); \
- local_irq_enable(); \
- 0; \
-})
#define smp_call_function_mask(mask, func, info, wait) \
(up_smp_call_function(func, info))
#define smp_call_function_many(mask, func, info, wait) \
diff --git a/kernel/Makefile b/kernel/Makefile
index 2921d90..2aebc4c 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -40,7 +40,11 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
-obj-$(CONFIG_USE_GENERIC_SMP_HELPERS) += smp.o
+ifeq ($(CONFIG_USE_GENERIC_SMP_HELPERS),y)
+obj-y += smp.o
+else
+obj-y += up.o
+endif
obj-$(CONFIG_SMP) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 1cff28d..7c4142a 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -136,29 +136,47 @@ static int stutter_pause_test = 0;
#endif
int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;

-#define FULLSTOP_SHUTDOWN 1 /* Bail due to system shutdown/panic. */
-#define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */
-static int fullstop; /* stop generating callbacks at test end. */
-DEFINE_MUTEX(fullstop_mutex); /* protect fullstop transitions and */
- /* spawning of kthreads. */
+/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
+
+#define FULLSTOP_DONTSTOP 0 /* Normal operation. */
+#define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */
+#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */
+static int fullstop = FULLSTOP_RMMOD;
+DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */
+ /* of kthreads. */

/*
- * Detect and respond to a signal-based shutdown.
+ * Detect and respond to a system shutdown.
*/
static int
rcutorture_shutdown_notify(struct notifier_block *unused1,
unsigned long unused2, void *unused3)
{
- if (fullstop)
- return NOTIFY_DONE;
mutex_lock(&fullstop_mutex);
- if (!fullstop)
+ if (fullstop == FULLSTOP_DONTSTOP)
fullstop = FULLSTOP_SHUTDOWN;
+ else
+ printk(KERN_WARNING /* but going down anyway, so... */
+ "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
mutex_unlock(&fullstop_mutex);
return NOTIFY_DONE;
}

/*
+ * Absorb kthreads into a kernel function that won't return, so that
+ * they won't ever access module text or data again.
+ */
+static void rcutorture_shutdown_absorb(char *title)
+{
+ if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
+ printk(KERN_NOTICE
+ "rcutorture thread %s parking due to system shutdown\n",
+ title);
+ schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
+ }
+}
+
+/*
* Allocate an element from the rcu_tortures pool.
*/
static struct rcu_torture *
@@ -219,13 +237,14 @@ rcu_random(struct rcu_random_state *rrsp)
}

static void
-rcu_stutter_wait(void)
+rcu_stutter_wait(char *title)
{
- while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) {
+ while (stutter_pause_test || !rcutorture_runnable) {
if (rcutorture_runnable)
schedule_timeout_interruptible(1);
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
+ rcutorture_shutdown_absorb(title);
}
}

@@ -287,7 +306,7 @@ rcu_torture_cb(struct rcu_head *p)
int i;
struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);

- if (fullstop) {
+ if (fullstop != FULLSTOP_DONTSTOP) {
/* Test is ending, just drop callbacks on the floor. */
/* The next initialization will pick up the pieces. */
return;
@@ -619,10 +638,11 @@ rcu_torture_writer(void *arg)
}
rcu_torture_current_version++;
oldbatch = cur_ops->completed();
- rcu_stutter_wait();
- } while (!kthread_should_stop() && !fullstop);
+ rcu_stutter_wait("rcu_torture_writer");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
- while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
+ rcutorture_shutdown_absorb("rcu_torture_writer");
+ while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -643,11 +663,12 @@ rcu_torture_fakewriter(void *arg)
schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
udelay(rcu_random(&rand) & 0x3ff);
cur_ops->sync();
- rcu_stutter_wait();
- } while (!kthread_should_stop() && !fullstop);
+ rcu_stutter_wait("rcu_torture_fakewriter");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);

VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
- while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
+ rcutorture_shutdown_absorb("rcu_torture_fakewriter");
+ while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -752,12 +773,13 @@ rcu_torture_reader(void *arg)
preempt_enable();
cur_ops->readunlock(idx);
schedule();
- rcu_stutter_wait();
- } while (!kthread_should_stop() && !fullstop);
+ rcu_stutter_wait("rcu_torture_reader");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
+ rcutorture_shutdown_absorb("rcu_torture_reader");
if (irqreader && cur_ops->irqcapable)
del_timer_sync(&t);
- while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
+ while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -854,7 +876,8 @@ rcu_torture_stats(void *arg)
do {
schedule_timeout_interruptible(stat_interval * HZ);
rcu_torture_stats_print();
- } while (!kthread_should_stop() && !fullstop);
+ rcutorture_shutdown_absorb("rcu_torture_stats");
+ } while (!kthread_should_stop());
VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
return 0;
}
@@ -866,52 +889,49 @@ static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
*/
static void rcu_torture_shuffle_tasks(void)
{
- cpumask_var_t tmp_mask;
+ cpumask_t tmp_mask;
int i;

- if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL))
- BUG();
-
- cpumask_setall(tmp_mask);
+ cpus_setall(tmp_mask);
get_online_cpus();

/* No point in shuffling if there is only one online CPU (ex: UP) */
- if (num_online_cpus() == 1)
- goto out;
+ if (num_online_cpus() == 1) {
+ put_online_cpus();
+ return;
+ }

if (rcu_idle_cpu != -1)
- cpumask_clear_cpu(rcu_idle_cpu, tmp_mask);
+ cpu_clear(rcu_idle_cpu, tmp_mask);

- set_cpus_allowed_ptr(current, tmp_mask);
+ set_cpus_allowed_ptr(current, &tmp_mask);

if (reader_tasks) {
for (i = 0; i < nrealreaders; i++)
if (reader_tasks[i])
set_cpus_allowed_ptr(reader_tasks[i],
- tmp_mask);
+ &tmp_mask);
}

if (fakewriter_tasks) {
for (i = 0; i < nfakewriters; i++)
if (fakewriter_tasks[i])
set_cpus_allowed_ptr(fakewriter_tasks[i],
- tmp_mask);
+ &tmp_mask);
}

if (writer_task)
- set_cpus_allowed_ptr(writer_task, tmp_mask);
+ set_cpus_allowed_ptr(writer_task, &tmp_mask);

if (stats_task)
- set_cpus_allowed_ptr(stats_task, tmp_mask);
+ set_cpus_allowed_ptr(stats_task, &tmp_mask);

if (rcu_idle_cpu == -1)
rcu_idle_cpu = num_online_cpus() - 1;
else
rcu_idle_cpu--;

-out:
put_online_cpus();
- free_cpumask_var(tmp_mask);
}

/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
@@ -925,7 +945,8 @@ rcu_torture_shuffle(void *arg)
do {
schedule_timeout_interruptible(shuffle_interval * HZ);
rcu_torture_shuffle_tasks();
- } while (!kthread_should_stop() && !fullstop);
+ rcutorture_shutdown_absorb("rcu_torture_shuffle");
+ } while (!kthread_should_stop());
VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
return 0;
}
@@ -940,10 +961,11 @@ rcu_torture_stutter(void *arg)
do {
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 1;
- if (!kthread_should_stop() && !fullstop)
+ if (!kthread_should_stop())
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 0;
- } while (!kthread_should_stop() && !fullstop);
+ rcutorture_shutdown_absorb("rcu_torture_stutter");
+ } while (!kthread_should_stop());
VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
return 0;
}
@@ -970,15 +992,16 @@ rcu_torture_cleanup(void)
int i;

mutex_lock(&fullstop_mutex);
- if (!fullstop) {
- /* If being signaled, let it happen, then exit. */
+ if (fullstop == FULLSTOP_SHUTDOWN) {
+ printk(KERN_WARNING /* but going down anyway, so... */
+ "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
mutex_unlock(&fullstop_mutex);
- schedule_timeout_interruptible(10 * HZ);
+ schedule_timeout_uninterruptible(10);
if (cur_ops->cb_barrier != NULL)
cur_ops->cb_barrier();
return;
}
- fullstop = FULLSTOP_CLEANUP;
+ fullstop = FULLSTOP_RMMOD;
mutex_unlock(&fullstop_mutex);
unregister_reboot_notifier(&rcutorture_nb);
if (stutter_task) {
@@ -1078,7 +1101,7 @@ rcu_torture_init(void)
else
nrealreaders = 2 * num_online_cpus();
rcu_torture_print_module_parms("Start of test");
- fullstop = 0;
+ fullstop = FULLSTOP_DONTSTOP;

/* Set up the freelist. */

diff --git a/kernel/up.c b/kernel/up.c
new file mode 100644
index 0000000..c04b9dc
--- /dev/null
+++ b/kernel/up.c
@@ -0,0 +1,20 @@
+/*
+ * Uniprocessor-only support functions. The counterpart to kernel/smp.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+
+int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+ int wait)
+{
+ WARN_ON(cpu != 0);
+
+ local_irq_disable();
+ (func)(info);
+ local_irq_enable();
+
+ return 0;
+}
+EXPORT_SYMBOL(smp_call_function_single);
--
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