diff options
Diffstat (limited to 'kernel/softirq.c')
-rw-r--r-- | kernel/softirq.c | 34 |
1 files changed, 28 insertions, 6 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 57d3f67f6f38..d105a82543d0 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c | |||
@@ -21,8 +21,10 @@ | |||
21 | #include <linux/freezer.h> | 21 | #include <linux/freezer.h> |
22 | #include <linux/kthread.h> | 22 | #include <linux/kthread.h> |
23 | #include <linux/rcupdate.h> | 23 | #include <linux/rcupdate.h> |
24 | #include <linux/ftrace.h> | ||
24 | #include <linux/smp.h> | 25 | #include <linux/smp.h> |
25 | #include <linux/tick.h> | 26 | #include <linux/tick.h> |
27 | #include <trace/irq.h> | ||
26 | 28 | ||
27 | #include <asm/irq.h> | 29 | #include <asm/irq.h> |
28 | /* | 30 | /* |
@@ -52,6 +54,11 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp | |||
52 | 54 | ||
53 | static DEFINE_PER_CPU(struct task_struct *, ksoftirqd); | 55 | static DEFINE_PER_CPU(struct task_struct *, ksoftirqd); |
54 | 56 | ||
57 | char *softirq_to_name[NR_SOFTIRQS] = { | ||
58 | "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", | ||
59 | "TASKLET", "SCHED", "HRTIMER", "RCU" | ||
60 | }; | ||
61 | |||
55 | /* | 62 | /* |
56 | * we cannot loop indefinitely here to avoid userspace starvation, | 63 | * we cannot loop indefinitely here to avoid userspace starvation, |
57 | * but we also don't want to introduce a worst case 1/HZ latency | 64 | * 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) | |||
79 | WARN_ON_ONCE(in_irq()); | 86 | WARN_ON_ONCE(in_irq()); |
80 | 87 | ||
81 | raw_local_irq_save(flags); | 88 | raw_local_irq_save(flags); |
82 | add_preempt_count(SOFTIRQ_OFFSET); | 89 | /* |
90 | * The preempt tracer hooks into add_preempt_count and will break | ||
91 | * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET | ||
92 | * is set and before current->softirq_enabled is cleared. | ||
93 | * We must manually increment preempt_count here and manually | ||
94 | * call the trace_preempt_off later. | ||
95 | */ | ||
96 | preempt_count() += SOFTIRQ_OFFSET; | ||
83 | /* | 97 | /* |
84 | * Were softirqs turned off above: | 98 | * Were softirqs turned off above: |
85 | */ | 99 | */ |
86 | if (softirq_count() == SOFTIRQ_OFFSET) | 100 | if (softirq_count() == SOFTIRQ_OFFSET) |
87 | trace_softirqs_off(ip); | 101 | trace_softirqs_off(ip); |
88 | raw_local_irq_restore(flags); | 102 | raw_local_irq_restore(flags); |
103 | |||
104 | if (preempt_count() == SOFTIRQ_OFFSET) | ||
105 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | ||
89 | } | 106 | } |
90 | #else /* !CONFIG_TRACE_IRQFLAGS */ | 107 | #else /* !CONFIG_TRACE_IRQFLAGS */ |
91 | static inline void __local_bh_disable(unsigned long ip) | 108 | static inline void __local_bh_disable(unsigned long ip) |
@@ -169,6 +186,9 @@ EXPORT_SYMBOL(local_bh_enable_ip); | |||
169 | */ | 186 | */ |
170 | #define MAX_SOFTIRQ_RESTART 10 | 187 | #define MAX_SOFTIRQ_RESTART 10 |
171 | 188 | ||
189 | DEFINE_TRACE(softirq_entry); | ||
190 | DEFINE_TRACE(softirq_exit); | ||
191 | |||
172 | asmlinkage void __do_softirq(void) | 192 | asmlinkage void __do_softirq(void) |
173 | { | 193 | { |
174 | struct softirq_action *h; | 194 | struct softirq_action *h; |
@@ -180,7 +200,7 @@ asmlinkage void __do_softirq(void) | |||
180 | account_system_vtime(current); | 200 | account_system_vtime(current); |
181 | 201 | ||
182 | __local_bh_disable((unsigned long)__builtin_return_address(0)); | 202 | __local_bh_disable((unsigned long)__builtin_return_address(0)); |
183 | trace_softirq_enter(); | 203 | lockdep_softirq_enter(); |
184 | 204 | ||
185 | cpu = smp_processor_id(); | 205 | cpu = smp_processor_id(); |
186 | restart: | 206 | restart: |
@@ -195,12 +215,14 @@ restart: | |||
195 | if (pending & 1) { | 215 | if (pending & 1) { |
196 | int prev_count = preempt_count(); | 216 | int prev_count = preempt_count(); |
197 | 217 | ||
218 | trace_softirq_entry(h, softirq_vec); | ||
198 | h->action(h); | 219 | h->action(h); |
199 | 220 | trace_softirq_exit(h, softirq_vec); | |
200 | if (unlikely(prev_count != preempt_count())) { | 221 | if (unlikely(prev_count != preempt_count())) { |
201 | printk(KERN_ERR "huh, entered softirq %td %p" | 222 | printk(KERN_ERR "huh, entered softirq %td %s %p" |
202 | "with preempt_count %08x," | 223 | "with preempt_count %08x," |
203 | " exited with %08x?\n", h - softirq_vec, | 224 | " exited with %08x?\n", h - softirq_vec, |
225 | softirq_to_name[h - softirq_vec], | ||
204 | h->action, prev_count, preempt_count()); | 226 | h->action, prev_count, preempt_count()); |
205 | preempt_count() = prev_count; | 227 | preempt_count() = prev_count; |
206 | } | 228 | } |
@@ -220,7 +242,7 @@ restart: | |||
220 | if (pending) | 242 | if (pending) |
221 | wakeup_softirqd(); | 243 | wakeup_softirqd(); |
222 | 244 | ||
223 | trace_softirq_exit(); | 245 | lockdep_softirq_exit(); |
224 | 246 | ||
225 | account_system_vtime(current); | 247 | account_system_vtime(current); |
226 | _local_bh_enable(); | 248 | _local_bh_enable(); |
@@ -496,7 +518,7 @@ static int __try_remote_softirq(struct call_single_data *cp, int cpu, int softir | |||
496 | cp->flags = 0; | 518 | cp->flags = 0; |
497 | cp->priv = softirq; | 519 | cp->priv = softirq; |
498 | 520 | ||
499 | __smp_call_function_single(cpu, cp); | 521 | __smp_call_function_single(cpu, cp, 0); |
500 | return 0; | 522 | return 0; |
501 | } | 523 | } |
502 | return 1; | 524 | return 1; |