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Merge branch 'core/urgent' into core/locking

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Prepare for dependent patch.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2013-11-27 11:09:19 +01:00
commit 7d5b158310
2 changed files with 47 additions and 10 deletions
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54
kernel/softirq.c
View File

@ -211,14 +211,52 @@ EXPORT_SYMBOL(local_bh_enable_ip);
#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2)
#define MAX_SOFTIRQ_RESTART 10
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* Convoluted means of passing __do_softirq() a message through the various
* architecture execute_on_stack() bits.
*
* When we run softirqs from irq_exit() and thus on the hardirq stack we need
* to keep the lockdep irq context tracking as tight as possible in order to
* not miss-qualify lock contexts and miss possible deadlocks.
*/
static DEFINE_PER_CPU(int, softirq_from_hardirq);
static inline void lockdep_softirq_from_hardirq(void)
{
this_cpu_write(softirq_from_hardirq, 1);
}
static inline void lockdep_softirq_start(void)
{
if (this_cpu_read(softirq_from_hardirq))
trace_hardirq_exit();
lockdep_softirq_enter();
}
static inline void lockdep_softirq_end(void)
{
lockdep_softirq_exit();
if (this_cpu_read(softirq_from_hardirq)) {
this_cpu_write(softirq_from_hardirq, 0);
trace_hardirq_enter();
}
}
#else
static inline void lockdep_softirq_from_hardirq(void) { }
static inline void lockdep_softirq_start(void) { }
static inline void lockdep_softirq_end(void) { }
#endif
asmlinkage void __do_softirq(void)
{
struct softirq_action *h;
__u32 pending;
unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
int cpu;
unsigned long old_flags = current->flags;
int max_restart = MAX_SOFTIRQ_RESTART;
struct softirq_action *h;
__u32 pending;
int cpu;
/*
* Mask out PF_MEMALLOC s current task context is borrowed for the
@ -231,7 +269,7 @@ asmlinkage void __do_softirq(void)
account_irq_enter_time(current);
__local_bh_disable(_RET_IP_, SOFTIRQ_OFFSET);
lockdep_softirq_enter();
lockdep_softirq_start();
cpu = smp_processor_id();
restart:
@ -278,16 +316,13 @@ restart:
wakeup_softirqd();
}
lockdep_softirq_exit();
lockdep_softirq_end();
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
WARN_ON_ONCE(in_interrupt());
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
}
asmlinkage void do_softirq(void)
{
__u32 pending;
@ -330,6 +365,7 @@ void irq_enter(void)
static inline void invoke_softirq(void)
{
if (!force_irqthreads) {
lockdep_softirq_from_hardirq();
#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
/*
* We can safely execute softirq on the current stack if
@ -375,13 +411,13 @@ void irq_exit(void)
#endif
account_irq_exit_time(current);
trace_hardirq_exit();
preempt_count_sub(HARDIRQ_OFFSET);
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();
tick_irq_exit();
rcu_irq_exit();
trace_hardirq_exit(); /* must be last! */
}
/*

3
lib/Kconfig
View File

@ -342,7 +342,8 @@ config CHECK_SIGNATURE
bool
config CPUMASK_OFFSTACK
bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
bool "Force CPU masks off stack"
depends on SMP
help
Use dynamic allocation for cpumask_var_t, instead of putting
them on the stack. This is a bit more expensive, but avoids