Commit 3386c05b authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'core-fixes-for-linus' of...

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

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()
parents 1e70c7f7 6552ebae
......@@ -633,6 +633,7 @@ static int hpet_cpuhp_notify(struct notifier_block *n,
/* FIXME: add schedule_work_on() */
schedule_delayed_work_on(cpu, &work.work, 0);
wait_for_completion(&work.complete);
destroy_timer_on_stack(&work.work.timer);
break;
case CPU_DEAD:
if (hdev) {
......
......@@ -393,16 +393,21 @@ oprofile_write_reserve(struct op_entry *entry, struct pt_regs * const regs,
return;
fail:
entry->event = NULL;
cpu_buf->sample_lost_overflow++;
}
int oprofile_add_data(struct op_entry *entry, unsigned long val)
{
if (!entry->event)
return 0;
return op_cpu_buffer_add_data(entry, val);
}
int oprofile_write_commit(struct op_entry *entry)
{
if (!entry->event)
return -EINVAL;
return op_cpu_buffer_write_commit(entry);
}
......
......@@ -66,6 +66,13 @@ static inline void op_cpu_buffer_reset(int cpu)
cpu_buf->last_task = NULL;
}
/*
* op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
* called only if op_cpu_buffer_write_reserve() did not return NULL or
* entry->event != NULL, otherwise entry->size or entry->event will be
* used uninitialized.
*/
struct op_sample
*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
int op_cpu_buffer_write_commit(struct op_entry *entry);
......
......@@ -293,6 +293,9 @@ extern void sched_show_task(struct task_struct *p);
extern void softlockup_tick(void);
extern void touch_softlockup_watchdog(void);
extern void touch_all_softlockup_watchdogs(void);
extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
struct file *filp, void __user *buffer,
size_t *lenp, loff_t *ppos);
extern unsigned int softlockup_panic;
extern unsigned long sysctl_hung_task_check_count;
extern unsigned long sysctl_hung_task_timeout_secs;
......
......@@ -130,6 +130,12 @@ struct execute_work {
init_timer_deferrable(&(_work)->timer); \
} while (0)
#define INIT_DELAYED_WORK_ON_STACK(_work, _func) \
do { \
INIT_WORK(&(_work)->work, (_func)); \
init_timer_on_stack(&(_work)->timer); \
} while (0)
/**
* work_pending - Find out whether a work item is currently pending
* @work: The work item in question
......
......@@ -238,6 +238,98 @@ config AUDIT_TREE
def_bool y
depends on AUDITSYSCALL && INOTIFY
menu "RCU Subsystem"
choice
prompt "RCU Implementation"
default CLASSIC_RCU
config CLASSIC_RCU
bool "Classic RCU"
help
This option selects the classic RCU implementation that is
designed for best read-side performance on non-realtime
systems.
Select this option if you are unsure.
config TREE_RCU
bool "Tree-based hierarchical RCU"
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
thousands of CPUs.
config PREEMPT_RCU
bool "Preemptible RCU"
depends on PREEMPT
help
This option reduces the latency of the kernel by making certain
RCU sections preemptible. Normally RCU code is non-preemptible, if
this option is selected then read-only RCU sections become
preemptible. This helps latency, but may expose bugs due to
now-naive assumptions about each RCU read-side critical section
remaining on a given CPU through its execution.
endchoice
config RCU_TRACE
bool "Enable tracing for RCU"
depends on TREE_RCU || PREEMPT_RCU
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
Say Y here if you want to enable RCU tracing
Say N if you are unsure.
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
depends on TREE_RCU
default 64 if 64BIT
default 32 if !64BIT
help
This option controls the fanout of hierarchical implementations
of RCU, allowing RCU to work efficiently on machines with
large numbers of CPUs. This value must be at least the cube
root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
systems and up to 262,144 for 64-bit systems.
Select a specific number if testing RCU itself.
Take the default if unsure.
config RCU_FANOUT_EXACT
bool "Disable tree-based hierarchical RCU auto-balancing"
depends on TREE_RCU
default n
help
This option forces use of the exact RCU_FANOUT value specified,
regardless of imbalances in the hierarchy. This is useful for
testing RCU itself, and might one day be useful on systems with
strong NUMA behavior.
Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
Say N if unsure.
config TREE_RCU_TRACE
def_bool RCU_TRACE && TREE_RCU
select DEBUG_FS
help
This option provides tracing for the TREE_RCU implementation,
permitting Makefile to trivially select kernel/rcutree_trace.c.
config PREEMPT_RCU_TRACE
def_bool RCU_TRACE && PREEMPT_RCU
select DEBUG_FS
help
This option provides tracing for the PREEMPT_RCU implementation,
permitting Makefile to trivially select kernel/rcupreempt_trace.c.
endmenu # "RCU Subsystem"
config IKCONFIG
tristate "Kernel .config support"
---help---
......@@ -972,90 +1064,3 @@ source "block/Kconfig"
config PREEMPT_NOTIFIERS
bool
choice
prompt "RCU Implementation"
default CLASSIC_RCU
config CLASSIC_RCU
bool "Classic RCU"
help
This option selects the classic RCU implementation that is
designed for best read-side performance on non-realtime
systems.
Select this option if you are unsure.
config TREE_RCU
bool "Tree-based hierarchical RCU"
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
thousands of CPUs.
config PREEMPT_RCU
bool "Preemptible RCU"
depends on PREEMPT
help
This option reduces the latency of the kernel by making certain
RCU sections preemptible. Normally RCU code is non-preemptible, if
this option is selected then read-only RCU sections become
preemptible. This helps latency, but may expose bugs due to
now-naive assumptions about each RCU read-side critical section
remaining on a given CPU through its execution.
endchoice
config RCU_TRACE
bool "Enable tracing for RCU"
depends on TREE_RCU || PREEMPT_RCU
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
Say Y here if you want to enable RCU tracing
Say N if you are unsure.
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
depends on TREE_RCU
default 64 if 64BIT
default 32 if !64BIT
help
This option controls the fanout of hierarchical implementations
of RCU, allowing RCU to work efficiently on machines with
large numbers of CPUs. This value must be at least the cube
root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
systems and up to 262,144 for 64-bit systems.
Select a specific number if testing RCU itself.
Take the default if unsure.
config RCU_FANOUT_EXACT
bool "Disable tree-based hierarchical RCU auto-balancing"
depends on TREE_RCU
default n
help
This option forces use of the exact RCU_FANOUT value specified,
regardless of imbalances in the hierarchy. This is useful for
testing RCU itself, and might one day be useful on systems with
strong NUMA behavior.
Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
Say N if unsure.
config TREE_RCU_TRACE
def_bool RCU_TRACE && TREE_RCU
select DEBUG_FS
help
This option provides tracing for the TREE_RCU implementation,
permitting Makefile to trivially select kernel/rcutree_trace.c.
config PREEMPT_RCU_TRACE
def_bool RCU_TRACE && PREEMPT_RCU
select DEBUG_FS
help
This option provides tracing for the PREEMPT_RCU implementation,
permitting Makefile to trivially select kernel/rcupreempt_trace.c.
......@@ -716,7 +716,7 @@ void rcu_check_callbacks(int cpu, int user)
raise_rcu_softirq();
}
static void rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp,
static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp,
struct rcu_data *rdp)
{
unsigned long flags;
......
......@@ -1314,7 +1314,7 @@ int rcu_needs_cpu(int cpu)
* access due to the fact that this CPU cannot possibly have any RCU
* callbacks in flight yet.
*/
static void
static void __cpuinit
rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
{
unsigned long flags;
......
......@@ -663,8 +663,10 @@ int relay_late_setup_files(struct rchan *chan,
mutex_lock(&relay_channels_mutex);
/* Is chan already set up? */
if (unlikely(chan->has_base_filename))
if (unlikely(chan->has_base_filename)) {
mutex_unlock(&relay_channels_mutex);
return -EEXIST;
}
chan->has_base_filename = 1;
chan->parent = parent;
curr_cpu = get_cpu();
......
......@@ -16,6 +16,7 @@
#include <linux/lockdep.h>
#include <linux/notifier.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <asm/irq_regs.h>
......@@ -88,6 +89,14 @@ void touch_all_softlockup_watchdogs(void)
}
EXPORT_SYMBOL(touch_all_softlockup_watchdogs);
int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
struct file *filp, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
touch_all_softlockup_watchdogs();
return proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
}
/*
* This callback runs from the timer interrupt, and checks
* whether the watchdog thread has hung or not:
......
......@@ -809,7 +809,7 @@ static struct ctl_table kern_table[] = {
.data = &softlockup_thresh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.proc_handler = &proc_dosoftlockup_thresh,
.strategy = &sysctl_intvec,
.extra1 = &neg_one,
.extra2 = &sixty,
......
......@@ -640,19 +640,6 @@ config RCU_TORTURE_TEST_RUNNABLE
Say N here if you want the RCU torture tests to start only
after being manually enabled via /proc.
config RCU_CPU_STALL_DETECTOR
bool "Check for stalled CPUs delaying RCU grace periods"
depends on CLASSIC_RCU
default n
help
This option causes RCU to printk information on which
CPUs are delaying the current grace period, but only when
the grace period extends for excessive time periods.
Say Y if you want RCU to perform such checks.
Say N if you are unsure.
config RCU_CPU_STALL_DETECTOR
bool "Check for stalled CPUs delaying RCU grace periods"
depends on CLASSIC_RCU || TREE_RCU
......
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