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-rw-r--r--kernel/softirq.c32
1 files changed, 27 insertions, 5 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 57d3f67..65ff3e3 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -21,8 +21,10 @@
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/rcupdate.h>
+#include <linux/ftrace.h>
#include <linux/smp.h>
#include <linux/tick.h>
+#include <trace/irq.h>
#include <asm/irq.h>
/*
@@ -52,6 +54,11 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp
static DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
+char *softirq_to_name[NR_SOFTIRQS] = {
+ "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK",
+ "TASKLET", "SCHED", "HRTIMER", "RCU"
+};
+
/*
* we cannot loop indefinitely here to avoid userspace starvation,
* but we also don't want to introduce a worst case 1/HZ latency
@@ -79,13 +86,23 @@ static void __local_bh_disable(unsigned long ip)
WARN_ON_ONCE(in_irq());
raw_local_irq_save(flags);
- add_preempt_count(SOFTIRQ_OFFSET);
+ /*
+ * The preempt tracer hooks into add_preempt_count and will break
+ * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET
+ * is set and before current->softirq_enabled is cleared.
+ * We must manually increment preempt_count here and manually
+ * call the trace_preempt_off later.
+ */
+ preempt_count() += SOFTIRQ_OFFSET;
/*
* Were softirqs turned off above:
*/
if (softirq_count() == SOFTIRQ_OFFSET)
trace_softirqs_off(ip);
raw_local_irq_restore(flags);
+
+ if (preempt_count() == SOFTIRQ_OFFSET)
+ trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
}
#else /* !CONFIG_TRACE_IRQFLAGS */
static inline void __local_bh_disable(unsigned long ip)
@@ -169,6 +186,9 @@ EXPORT_SYMBOL(local_bh_enable_ip);
*/
#define MAX_SOFTIRQ_RESTART 10
+DEFINE_TRACE(softirq_entry);
+DEFINE_TRACE(softirq_exit);
+
asmlinkage void __do_softirq(void)
{
struct softirq_action *h;
@@ -180,7 +200,7 @@ asmlinkage void __do_softirq(void)
account_system_vtime(current);
__local_bh_disable((unsigned long)__builtin_return_address(0));
- trace_softirq_enter();
+ lockdep_softirq_enter();
cpu = smp_processor_id();
restart:
@@ -195,12 +215,14 @@ restart:
if (pending & 1) {
int prev_count = preempt_count();
+ trace_softirq_entry(h, softirq_vec);
h->action(h);
-
+ trace_softirq_exit(h, softirq_vec);
if (unlikely(prev_count != preempt_count())) {
- printk(KERN_ERR "huh, entered softirq %td %p"
+ printk(KERN_ERR "huh, entered softirq %td %s %p"
"with preempt_count %08x,"
" exited with %08x?\n", h - softirq_vec,
+ softirq_to_name[h - softirq_vec],
h->action, prev_count, preempt_count());
preempt_count() = prev_count;
}
@@ -220,7 +242,7 @@ restart:
if (pending)
wakeup_softirqd();
- trace_softirq_exit();
+ lockdep_softirq_exit();
account_system_vtime(current);
_local_bh_enable();
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