Blame view
kernel/softirq.c
19 KB
1da177e4c Linux-2.6.12-rc2 |
1 2 3 4 5 |
/* * linux/kernel/softirq.c * * Copyright (C) 1992 Linus Torvalds * |
b10db7f0d time: more timer ... |
6 7 8 |
* Distribute under GPLv2. * * Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903) |
1da177e4c Linux-2.6.12-rc2 |
9 |
*/ |
403227641 softirq: convert ... |
10 |
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9984de1a5 kernel: Map most ... |
11 |
#include <linux/export.h> |
1da177e4c Linux-2.6.12-rc2 |
12 13 14 15 16 17 18 |
#include <linux/kernel_stat.h> #include <linux/interrupt.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/notifier.h> #include <linux/percpu.h> #include <linux/cpu.h> |
831441862 Freezer: make ker... |
19 |
#include <linux/freezer.h> |
1da177e4c Linux-2.6.12-rc2 |
20 21 |
#include <linux/kthread.h> #include <linux/rcupdate.h> |
7e49fcce1 trace, lockdep: m... |
22 |
#include <linux/ftrace.h> |
78eef01b0 [PATCH] on_each_c... |
23 |
#include <linux/smp.h> |
3e339b5da softirq: Use hotp... |
24 |
#include <linux/smpboot.h> |
79bf2bb33 [PATCH] tick-mana... |
25 |
#include <linux/tick.h> |
d532676cc softirq: Add linu... |
26 |
#include <linux/irq.h> |
a0e39ed37 tracing: fix buil... |
27 28 |
#define CREATE_TRACE_POINTS |
ad8d75fff tracing/events: m... |
29 |
#include <trace/events/irq.h> |
1da177e4c Linux-2.6.12-rc2 |
30 |
|
1da177e4c Linux-2.6.12-rc2 |
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 |
/* - No shared variables, all the data are CPU local. - If a softirq needs serialization, let it serialize itself by its own spinlocks. - Even if softirq is serialized, only local cpu is marked for execution. Hence, we get something sort of weak cpu binding. Though it is still not clear, will it result in better locality or will not. Examples: - NET RX softirq. It is multithreaded and does not require any global serialization. - NET TX softirq. It kicks software netdevice queues, hence it is logically serialized per device, but this serialization is invisible to common code. - Tasklets: serialized wrt itself. */ #ifndef __ARCH_IRQ_STAT irq_cpustat_t irq_stat[NR_CPUS] ____cacheline_aligned; EXPORT_SYMBOL(irq_stat); #endif |
978b0116c softirq: allocate... |
53 |
static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp; |
1da177e4c Linux-2.6.12-rc2 |
54 |
|
4dd53d891 softirqs: Free up... |
55 |
DEFINE_PER_CPU(struct task_struct *, ksoftirqd); |
1da177e4c Linux-2.6.12-rc2 |
56 |
|
ce85b4f2e softirq: use cons... |
57 |
const char * const softirq_to_name[NR_SOFTIRQS] = { |
f660f6066 softirq: Display ... |
58 |
"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "IRQ_POLL", |
09223371d rcu: Use softirq ... |
59 |
"TASKLET", "SCHED", "HRTIMER", "RCU" |
5d592b44b tracing: tracepoi... |
60 |
}; |
1da177e4c Linux-2.6.12-rc2 |
61 62 63 64 65 66 |
/* * we cannot loop indefinitely here to avoid userspace starvation, * but we also don't want to introduce a worst case 1/HZ latency * to the pending events, so lets the scheduler to balance * the softirq load for us. */ |
676cb02dc softirqs: Make wa... |
67 |
static void wakeup_softirqd(void) |
1da177e4c Linux-2.6.12-rc2 |
68 69 |
{ /* Interrupts are disabled: no need to stop preemption */ |
909ea9646 core: Replace __g... |
70 |
struct task_struct *tsk = __this_cpu_read(ksoftirqd); |
1da177e4c Linux-2.6.12-rc2 |
71 72 73 74 75 76 |
if (tsk && tsk->state != TASK_RUNNING) wake_up_process(tsk); } /* |
4cd13c21b softirq: Let ksof... |
77 78 79 80 81 82 83 84 85 86 87 |
* If ksoftirqd is scheduled, we do not want to process pending softirqs * right now. Let ksoftirqd handle this at its own rate, to get fairness. */ static bool ksoftirqd_running(void) { struct task_struct *tsk = __this_cpu_read(ksoftirqd); return tsk && (tsk->state == TASK_RUNNING); } /* |
75e1056f5 sched: Fix softir... |
88 89 90 91 92 93 94 95 96 97 |
* preempt_count and SOFTIRQ_OFFSET usage: * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving * softirq processing. * - preempt_count is changed by SOFTIRQ_DISABLE_OFFSET (= 2 * SOFTIRQ_OFFSET) * on local_bh_disable or local_bh_enable. * This lets us distinguish between whether we are currently processing * softirq and whether we just have bh disabled. */ /* |
de30a2b35 [PATCH] lockdep: ... |
98 99 100 |
* This one is for softirq.c-internal use, * where hardirqs are disabled legitimately: */ |
3c829c367 [PATCH] Reducing ... |
101 |
#ifdef CONFIG_TRACE_IRQFLAGS |
0bd3a173d sched/preempt, lo... |
102 |
void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) |
de30a2b35 [PATCH] lockdep: ... |
103 104 105 106 107 108 |
{ unsigned long flags; WARN_ON_ONCE(in_irq()); raw_local_irq_save(flags); |
7e49fcce1 trace, lockdep: m... |
109 |
/* |
bdb438065 sched: Extract th... |
110 |
* The preempt tracer hooks into preempt_count_add and will break |
7e49fcce1 trace, lockdep: m... |
111 112 113 114 115 |
* 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. */ |
bdb438065 sched: Extract th... |
116 |
__preempt_count_add(cnt); |
de30a2b35 [PATCH] lockdep: ... |
117 118 119 |
/* * Were softirqs turned off above: */ |
9ea4c3800 locking: Optimize... |
120 |
if (softirq_count() == (cnt & SOFTIRQ_MASK)) |
de30a2b35 [PATCH] lockdep: ... |
121 122 |
trace_softirqs_off(ip); raw_local_irq_restore(flags); |
7e49fcce1 trace, lockdep: m... |
123 |
|
0f1ba9a2c softirq/preempt: ... |
124 125 |
if (preempt_count() == cnt) { #ifdef CONFIG_DEBUG_PREEMPT |
f904f5826 sched/debug: Fix ... |
126 |
current->preempt_disable_ip = get_lock_parent_ip(); |
0f1ba9a2c softirq/preempt: ... |
127 |
#endif |
f904f5826 sched/debug: Fix ... |
128 |
trace_preempt_off(CALLER_ADDR0, get_lock_parent_ip()); |
0f1ba9a2c softirq/preempt: ... |
129 |
} |
de30a2b35 [PATCH] lockdep: ... |
130 |
} |
0bd3a173d sched/preempt, lo... |
131 |
EXPORT_SYMBOL(__local_bh_disable_ip); |
3c829c367 [PATCH] Reducing ... |
132 |
#endif /* CONFIG_TRACE_IRQFLAGS */ |
de30a2b35 [PATCH] lockdep: ... |
133 |
|
75e1056f5 sched: Fix softir... |
134 135 |
static void __local_bh_enable(unsigned int cnt) { |
75e1056f5 sched: Fix softir... |
136 |
WARN_ON_ONCE(!irqs_disabled()); |
9ea4c3800 locking: Optimize... |
137 |
if (softirq_count() == (cnt & SOFTIRQ_MASK)) |
d2e08473f softirq: Use _RET... |
138 |
trace_softirqs_on(_RET_IP_); |
bdb438065 sched: Extract th... |
139 |
preempt_count_sub(cnt); |
75e1056f5 sched: Fix softir... |
140 |
} |
de30a2b35 [PATCH] lockdep: ... |
141 142 143 144 145 146 147 |
/* * Special-case - softirqs can safely be enabled in * cond_resched_softirq(), or by __do_softirq(), * without processing still-pending softirqs: */ void _local_bh_enable(void) { |
5d60d3e7c irq: Improve a bi... |
148 |
WARN_ON_ONCE(in_irq()); |
75e1056f5 sched: Fix softir... |
149 |
__local_bh_enable(SOFTIRQ_DISABLE_OFFSET); |
de30a2b35 [PATCH] lockdep: ... |
150 |
} |
de30a2b35 [PATCH] lockdep: ... |
151 |
EXPORT_SYMBOL(_local_bh_enable); |
0bd3a173d sched/preempt, lo... |
152 |
void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) |
de30a2b35 [PATCH] lockdep: ... |
153 |
{ |
0f476b6d9 softirq: remove i... |
154 |
WARN_ON_ONCE(in_irq() || irqs_disabled()); |
3c829c367 [PATCH] Reducing ... |
155 |
#ifdef CONFIG_TRACE_IRQFLAGS |
0f476b6d9 softirq: remove i... |
156 |
local_irq_disable(); |
3c829c367 [PATCH] Reducing ... |
157 |
#endif |
de30a2b35 [PATCH] lockdep: ... |
158 159 160 |
/* * Are softirqs going to be turned on now: */ |
75e1056f5 sched: Fix softir... |
161 |
if (softirq_count() == SOFTIRQ_DISABLE_OFFSET) |
0f476b6d9 softirq: remove i... |
162 |
trace_softirqs_on(ip); |
de30a2b35 [PATCH] lockdep: ... |
163 164 165 |
/* * Keep preemption disabled until we are done with * softirq processing: |
ce85b4f2e softirq: use cons... |
166 |
*/ |
0bd3a173d sched/preempt, lo... |
167 |
preempt_count_sub(cnt - 1); |
de30a2b35 [PATCH] lockdep: ... |
168 |
|
0bed698a3 irq: Justify the ... |
169 170 171 172 173 |
if (unlikely(!in_interrupt() && local_softirq_pending())) { /* * Run softirq if any pending. And do it in its own stack * as we may be calling this deep in a task call stack already. */ |
de30a2b35 [PATCH] lockdep: ... |
174 |
do_softirq(); |
0bed698a3 irq: Justify the ... |
175 |
} |
de30a2b35 [PATCH] lockdep: ... |
176 |
|
bdb438065 sched: Extract th... |
177 |
preempt_count_dec(); |
3c829c367 [PATCH] Reducing ... |
178 |
#ifdef CONFIG_TRACE_IRQFLAGS |
0f476b6d9 softirq: remove i... |
179 |
local_irq_enable(); |
3c829c367 [PATCH] Reducing ... |
180 |
#endif |
de30a2b35 [PATCH] lockdep: ... |
181 182 |
preempt_check_resched(); } |
0bd3a173d sched/preempt, lo... |
183 |
EXPORT_SYMBOL(__local_bh_enable_ip); |
de30a2b35 [PATCH] lockdep: ... |
184 185 |
/* |
34376a50f Fix lockup relate... |
186 187 188 189 190 191 |
* We restart softirq processing for at most MAX_SOFTIRQ_RESTART times, * but break the loop if need_resched() is set or after 2 ms. * The MAX_SOFTIRQ_TIME provides a nice upper bound in most cases, but in * certain cases, such as stop_machine(), jiffies may cease to * increment and so we need the MAX_SOFTIRQ_RESTART limit as * well to make sure we eventually return from this method. |
1da177e4c Linux-2.6.12-rc2 |
192 |
* |
c10d73671 softirq: reduce l... |
193 |
* These limits have been established via experimentation. |
1da177e4c Linux-2.6.12-rc2 |
194 195 196 197 |
* The two things to balance is latency against fairness - * we want to handle softirqs as soon as possible, but they * should not be able to lock up the box. */ |
c10d73671 softirq: reduce l... |
198 |
#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2) |
34376a50f Fix lockup relate... |
199 |
#define MAX_SOFTIRQ_RESTART 10 |
1da177e4c Linux-2.6.12-rc2 |
200 |
|
f1a83e652 lockdep: Correctl... |
201 202 |
#ifdef CONFIG_TRACE_IRQFLAGS /* |
f1a83e652 lockdep: Correctl... |
203 204 205 206 |
* 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. */ |
f1a83e652 lockdep: Correctl... |
207 |
|
5c4853b60 lockdep: Simplify... |
208 |
static inline bool lockdep_softirq_start(void) |
f1a83e652 lockdep: Correctl... |
209 |
{ |
5c4853b60 lockdep: Simplify... |
210 |
bool in_hardirq = false; |
f1a83e652 lockdep: Correctl... |
211 |
|
5c4853b60 lockdep: Simplify... |
212 213 |
if (trace_hardirq_context(current)) { in_hardirq = true; |
f1a83e652 lockdep: Correctl... |
214 |
trace_hardirq_exit(); |
5c4853b60 lockdep: Simplify... |
215 |
} |
f1a83e652 lockdep: Correctl... |
216 |
lockdep_softirq_enter(); |
5c4853b60 lockdep: Simplify... |
217 218 |
return in_hardirq; |
f1a83e652 lockdep: Correctl... |
219 |
} |
5c4853b60 lockdep: Simplify... |
220 |
static inline void lockdep_softirq_end(bool in_hardirq) |
f1a83e652 lockdep: Correctl... |
221 222 |
{ lockdep_softirq_exit(); |
5c4853b60 lockdep: Simplify... |
223 224 |
if (in_hardirq) |
f1a83e652 lockdep: Correctl... |
225 |
trace_hardirq_enter(); |
f1a83e652 lockdep: Correctl... |
226 |
} |
f1a83e652 lockdep: Correctl... |
227 |
#else |
5c4853b60 lockdep: Simplify... |
228 229 |
static inline bool lockdep_softirq_start(void) { return false; } static inline void lockdep_softirq_end(bool in_hardirq) { } |
f1a83e652 lockdep: Correctl... |
230 |
#endif |
be7635e72 arch, ftrace: for... |
231 |
asmlinkage __visible void __softirq_entry __do_softirq(void) |
1da177e4c Linux-2.6.12-rc2 |
232 |
{ |
c10d73671 softirq: reduce l... |
233 |
unsigned long end = jiffies + MAX_SOFTIRQ_TIME; |
907aed48f mm: allow PF_MEMA... |
234 |
unsigned long old_flags = current->flags; |
34376a50f Fix lockup relate... |
235 |
int max_restart = MAX_SOFTIRQ_RESTART; |
f1a83e652 lockdep: Correctl... |
236 |
struct softirq_action *h; |
5c4853b60 lockdep: Simplify... |
237 |
bool in_hardirq; |
f1a83e652 lockdep: Correctl... |
238 |
__u32 pending; |
2e702b9f6 softirq: use ffs(... |
239 |
int softirq_bit; |
907aed48f mm: allow PF_MEMA... |
240 241 242 243 244 245 246 |
/* * Mask out PF_MEMALLOC s current task context is borrowed for the * softirq. A softirq handled such as network RX might set PF_MEMALLOC * again if the socket is related to swap */ current->flags &= ~PF_MEMALLOC; |
1da177e4c Linux-2.6.12-rc2 |
247 248 |
pending = local_softirq_pending(); |
6a61671bb cputime: Safely r... |
249 |
account_irq_enter_time(current); |
829035fd7 [PATCH] lockdep: ... |
250 |
|
0bd3a173d sched/preempt, lo... |
251 |
__local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); |
5c4853b60 lockdep: Simplify... |
252 |
in_hardirq = lockdep_softirq_start(); |
1da177e4c Linux-2.6.12-rc2 |
253 |
|
1da177e4c Linux-2.6.12-rc2 |
254 255 |
restart: /* Reset the pending bitmask before enabling irqs */ |
3f74478b5 [PATCH] x86-64: S... |
256 |
set_softirq_pending(0); |
1da177e4c Linux-2.6.12-rc2 |
257 |
|
c70f5d661 [PATCH] revert bo... |
258 |
local_irq_enable(); |
1da177e4c Linux-2.6.12-rc2 |
259 260 |
h = softirq_vec; |
2e702b9f6 softirq: use ffs(... |
261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 |
while ((softirq_bit = ffs(pending))) { unsigned int vec_nr; int prev_count; h += softirq_bit - 1; vec_nr = h - softirq_vec; prev_count = preempt_count(); kstat_incr_softirqs_this_cpu(vec_nr); trace_softirq_entry(vec_nr); h->action(h); trace_softirq_exit(vec_nr); if (unlikely(prev_count != preempt_count())) { |
403227641 softirq: convert ... |
276 277 |
pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x? ", |
2e702b9f6 softirq: use ffs(... |
278 279 280 |
vec_nr, softirq_to_name[vec_nr], h->action, prev_count, preempt_count()); preempt_count_set(prev_count); |
1da177e4c Linux-2.6.12-rc2 |
281 282 |
} h++; |
2e702b9f6 softirq: use ffs(... |
283 284 |
pending >>= softirq_bit; } |
1da177e4c Linux-2.6.12-rc2 |
285 |
|
284a8c93a rcu: Per-CPU oper... |
286 |
rcu_bh_qs(); |
c70f5d661 [PATCH] revert bo... |
287 |
local_irq_disable(); |
1da177e4c Linux-2.6.12-rc2 |
288 289 |
pending = local_softirq_pending(); |
c10d73671 softirq: reduce l... |
290 |
if (pending) { |
34376a50f Fix lockup relate... |
291 292 |
if (time_before(jiffies, end) && !need_resched() && --max_restart) |
c10d73671 softirq: reduce l... |
293 |
goto restart; |
1da177e4c Linux-2.6.12-rc2 |
294 |
|
1da177e4c Linux-2.6.12-rc2 |
295 |
wakeup_softirqd(); |
c10d73671 softirq: reduce l... |
296 |
} |
1da177e4c Linux-2.6.12-rc2 |
297 |
|
5c4853b60 lockdep: Simplify... |
298 |
lockdep_softirq_end(in_hardirq); |
6a61671bb cputime: Safely r... |
299 |
account_irq_exit_time(current); |
75e1056f5 sched: Fix softir... |
300 |
__local_bh_enable(SOFTIRQ_OFFSET); |
5d60d3e7c irq: Improve a bi... |
301 |
WARN_ON_ONCE(in_interrupt()); |
717a94b5f sched/core: Remov... |
302 |
current_restore_flags(old_flags, PF_MEMALLOC); |
1da177e4c Linux-2.6.12-rc2 |
303 |
} |
722a9f929 asmlinkage: Add e... |
304 |
asmlinkage __visible void do_softirq(void) |
1da177e4c Linux-2.6.12-rc2 |
305 306 307 308 309 310 311 312 313 314 |
{ __u32 pending; unsigned long flags; if (in_interrupt()) return; local_irq_save(flags); pending = local_softirq_pending(); |
4cd13c21b softirq: Let ksof... |
315 |
if (pending && !ksoftirqd_running()) |
7d65f4a65 irq: Consolidate ... |
316 |
do_softirq_own_stack(); |
1da177e4c Linux-2.6.12-rc2 |
317 318 319 |
local_irq_restore(flags); } |
dde4b2b5f [PATCH] uninline ... |
320 321 322 323 324 |
/* * Enter an interrupt context. */ void irq_enter(void) { |
64db4cfff "Tree RCU": scala... |
325 |
rcu_irq_enter(); |
0a8a2e78b timer: Fix bad id... |
326 |
if (is_idle_task(current) && !in_interrupt()) { |
d267f87fb sched: Call tick_... |
327 328 329 330 331 |
/* * Prevent raise_softirq from needlessly waking up ksoftirqd * here, as softirq will be serviced on return from interrupt. */ local_bh_disable(); |
5acac1be4 tick: Rename tick... |
332 |
tick_irq_enter(); |
d267f87fb sched: Call tick_... |
333 334 335 336 |
_local_bh_enable(); } __irq_enter(); |
dde4b2b5f [PATCH] uninline ... |
337 |
} |
8d32a307e genirq: Provide f... |
338 339 |
static inline void invoke_softirq(void) { |
4cd13c21b softirq: Let ksof... |
340 341 |
if (ksoftirqd_running()) return; |
ded797547 irq: Force hardir... |
342 |
if (!force_irqthreads) { |
cc1f02745 irq: Optimize sof... |
343 |
#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK |
ded797547 irq: Force hardir... |
344 345 346 |
/* * We can safely execute softirq on the current stack if * it is the irq stack, because it should be near empty |
cc1f02745 irq: Optimize sof... |
347 348 349 350 351 352 353 354 |
* at this stage. */ __do_softirq(); #else /* * Otherwise, irq_exit() is called on the task stack that can * be potentially deep already. So call softirq in its own stack * to prevent from any overrun. |
ded797547 irq: Force hardir... |
355 |
*/ |
be6e10164 irq: Optimize cal... |
356 |
do_softirq_own_stack(); |
cc1f02745 irq: Optimize sof... |
357 |
#endif |
ded797547 irq: Force hardir... |
358 |
} else { |
8d32a307e genirq: Provide f... |
359 |
wakeup_softirqd(); |
ded797547 irq: Force hardir... |
360 |
} |
8d32a307e genirq: Provide f... |
361 |
} |
1da177e4c Linux-2.6.12-rc2 |
362 |
|
67826eae8 nohz: Disable the... |
363 364 365 366 367 368 369 370 371 372 373 374 |
static inline void tick_irq_exit(void) { #ifdef CONFIG_NO_HZ_COMMON int cpu = smp_processor_id(); /* Make sure that timer wheel updates are propagated */ if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) { if (!in_interrupt()) tick_nohz_irq_exit(); } #endif } |
1da177e4c Linux-2.6.12-rc2 |
375 376 377 378 379 |
/* * Exit an interrupt context. Process softirqs if needed and possible: */ void irq_exit(void) { |
74eed0163 irq: Ensure irq_e... |
380 |
#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED |
4cd5d1115 irq: Don't re-ena... |
381 |
local_irq_disable(); |
74eed0163 irq: Ensure irq_e... |
382 383 384 |
#else WARN_ON_ONCE(!irqs_disabled()); #endif |
6a61671bb cputime: Safely r... |
385 |
account_irq_exit_time(current); |
bdb438065 sched: Extract th... |
386 |
preempt_count_sub(HARDIRQ_OFFSET); |
1da177e4c Linux-2.6.12-rc2 |
387 388 |
if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); |
79bf2bb33 [PATCH] tick-mana... |
389 |
|
67826eae8 nohz: Disable the... |
390 |
tick_irq_exit(); |
416eb33cd rcu: Fix early ca... |
391 |
rcu_irq_exit(); |
f1a83e652 lockdep: Correctl... |
392 |
trace_hardirq_exit(); /* must be last! */ |
1da177e4c Linux-2.6.12-rc2 |
393 394 395 396 397 |
} /* * This function must run with irqs disabled! */ |
7ad5b3a50 kernel: remove fa... |
398 |
inline void raise_softirq_irqoff(unsigned int nr) |
1da177e4c Linux-2.6.12-rc2 |
399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 |
{ __raise_softirq_irqoff(nr); /* * If we're in an interrupt or softirq, we're done * (this also catches softirq-disabled code). We will * actually run the softirq once we return from * the irq or softirq. * * Otherwise we wake up ksoftirqd to make sure we * schedule the softirq soon. */ if (!in_interrupt()) wakeup_softirqd(); } |
7ad5b3a50 kernel: remove fa... |
414 |
void raise_softirq(unsigned int nr) |
1da177e4c Linux-2.6.12-rc2 |
415 416 417 418 419 420 421 |
{ unsigned long flags; local_irq_save(flags); raise_softirq_irqoff(nr); local_irq_restore(flags); } |
f069686e4 tracing/softirq: ... |
422 423 424 425 426 |
void __raise_softirq_irqoff(unsigned int nr) { trace_softirq_raise(nr); or_softirq_pending(1UL << nr); } |
962cf36c5 Remove argument f... |
427 |
void open_softirq(int nr, void (*action)(struct softirq_action *)) |
1da177e4c Linux-2.6.12-rc2 |
428 |
{ |
1da177e4c Linux-2.6.12-rc2 |
429 430 |
softirq_vec[nr].action = action; } |
9ba5f005c softirq: introduc... |
431 432 433 |
/* * Tasklets */ |
ce85b4f2e softirq: use cons... |
434 |
struct tasklet_head { |
48f20a9a9 tasklets: execute... |
435 436 |
struct tasklet_struct *head; struct tasklet_struct **tail; |
1da177e4c Linux-2.6.12-rc2 |
437 |
}; |
4620b49f7 softirq: remove i... |
438 439 |
static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec); static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec); |
1da177e4c Linux-2.6.12-rc2 |
440 |
|
7ad5b3a50 kernel: remove fa... |
441 |
void __tasklet_schedule(struct tasklet_struct *t) |
1da177e4c Linux-2.6.12-rc2 |
442 443 444 445 |
{ unsigned long flags; local_irq_save(flags); |
48f20a9a9 tasklets: execute... |
446 |
t->next = NULL; |
909ea9646 core: Replace __g... |
447 448 |
*__this_cpu_read(tasklet_vec.tail) = t; __this_cpu_write(tasklet_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
449 450 451 |
raise_softirq_irqoff(TASKLET_SOFTIRQ); local_irq_restore(flags); } |
1da177e4c Linux-2.6.12-rc2 |
452 |
EXPORT_SYMBOL(__tasklet_schedule); |
7ad5b3a50 kernel: remove fa... |
453 |
void __tasklet_hi_schedule(struct tasklet_struct *t) |
1da177e4c Linux-2.6.12-rc2 |
454 455 456 457 |
{ unsigned long flags; local_irq_save(flags); |
48f20a9a9 tasklets: execute... |
458 |
t->next = NULL; |
909ea9646 core: Replace __g... |
459 460 |
*__this_cpu_read(tasklet_hi_vec.tail) = t; __this_cpu_write(tasklet_hi_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
461 462 463 |
raise_softirq_irqoff(HI_SOFTIRQ); local_irq_restore(flags); } |
1da177e4c Linux-2.6.12-rc2 |
464 |
EXPORT_SYMBOL(__tasklet_hi_schedule); |
7c692cbad tasklets: new tas... |
465 466 467 |
void __tasklet_hi_schedule_first(struct tasklet_struct *t) { BUG_ON(!irqs_disabled()); |
909ea9646 core: Replace __g... |
468 469 |
t->next = __this_cpu_read(tasklet_hi_vec.head); __this_cpu_write(tasklet_hi_vec.head, t); |
7c692cbad tasklets: new tas... |
470 471 |
__raise_softirq_irqoff(HI_SOFTIRQ); } |
7c692cbad tasklets: new tas... |
472 |
EXPORT_SYMBOL(__tasklet_hi_schedule_first); |
0766f788e latent_entropy: M... |
473 |
static __latent_entropy void tasklet_action(struct softirq_action *a) |
1da177e4c Linux-2.6.12-rc2 |
474 475 476 477 |
{ struct tasklet_struct *list; local_irq_disable(); |
909ea9646 core: Replace __g... |
478 479 |
list = __this_cpu_read(tasklet_vec.head); __this_cpu_write(tasklet_vec.head, NULL); |
22127e93c time: Replace __g... |
480 |
__this_cpu_write(tasklet_vec.tail, this_cpu_ptr(&tasklet_vec.head)); |
1da177e4c Linux-2.6.12-rc2 |
481 482 483 484 485 486 487 488 489 |
local_irq_enable(); while (list) { struct tasklet_struct *t = list; list = list->next; if (tasklet_trylock(t)) { if (!atomic_read(&t->count)) { |
ce85b4f2e softirq: use cons... |
490 491 |
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state)) |
1da177e4c Linux-2.6.12-rc2 |
492 493 494 495 496 497 498 499 500 |
BUG(); t->func(t->data); tasklet_unlock(t); continue; } tasklet_unlock(t); } local_irq_disable(); |
48f20a9a9 tasklets: execute... |
501 |
t->next = NULL; |
909ea9646 core: Replace __g... |
502 503 |
*__this_cpu_read(tasklet_vec.tail) = t; __this_cpu_write(tasklet_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
504 505 506 507 |
__raise_softirq_irqoff(TASKLET_SOFTIRQ); local_irq_enable(); } } |
0766f788e latent_entropy: M... |
508 |
static __latent_entropy void tasklet_hi_action(struct softirq_action *a) |
1da177e4c Linux-2.6.12-rc2 |
509 510 511 512 |
{ struct tasklet_struct *list; local_irq_disable(); |
909ea9646 core: Replace __g... |
513 514 |
list = __this_cpu_read(tasklet_hi_vec.head); __this_cpu_write(tasklet_hi_vec.head, NULL); |
22127e93c time: Replace __g... |
515 |
__this_cpu_write(tasklet_hi_vec.tail, this_cpu_ptr(&tasklet_hi_vec.head)); |
1da177e4c Linux-2.6.12-rc2 |
516 517 518 519 520 521 522 523 524 |
local_irq_enable(); while (list) { struct tasklet_struct *t = list; list = list->next; if (tasklet_trylock(t)) { if (!atomic_read(&t->count)) { |
ce85b4f2e softirq: use cons... |
525 526 |
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state)) |
1da177e4c Linux-2.6.12-rc2 |
527 528 529 530 531 532 533 534 535 |
BUG(); t->func(t->data); tasklet_unlock(t); continue; } tasklet_unlock(t); } local_irq_disable(); |
48f20a9a9 tasklets: execute... |
536 |
t->next = NULL; |
909ea9646 core: Replace __g... |
537 538 |
*__this_cpu_read(tasklet_hi_vec.tail) = t; __this_cpu_write(tasklet_hi_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
539 540 541 542 |
__raise_softirq_irqoff(HI_SOFTIRQ); local_irq_enable(); } } |
1da177e4c Linux-2.6.12-rc2 |
543 544 545 546 547 548 549 550 551 |
void tasklet_init(struct tasklet_struct *t, void (*func)(unsigned long), unsigned long data) { t->next = NULL; t->state = 0; atomic_set(&t->count, 0); t->func = func; t->data = data; } |
1da177e4c Linux-2.6.12-rc2 |
552 553 554 555 556 |
EXPORT_SYMBOL(tasklet_init); void tasklet_kill(struct tasklet_struct *t) { if (in_interrupt()) |
403227641 softirq: convert ... |
557 558 |
pr_notice("Attempt to kill tasklet from interrupt "); |
1da177e4c Linux-2.6.12-rc2 |
559 560 |
while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { |
79d381c9f kernel/softirq.c:... |
561 |
do { |
1da177e4c Linux-2.6.12-rc2 |
562 |
yield(); |
79d381c9f kernel/softirq.c:... |
563 |
} while (test_bit(TASKLET_STATE_SCHED, &t->state)); |
1da177e4c Linux-2.6.12-rc2 |
564 565 566 567 |
} tasklet_unlock_wait(t); clear_bit(TASKLET_STATE_SCHED, &t->state); } |
1da177e4c Linux-2.6.12-rc2 |
568 |
EXPORT_SYMBOL(tasklet_kill); |
9ba5f005c softirq: introduc... |
569 570 571 572 573 |
/* * tasklet_hrtimer */ /* |
b9c303227 hrtimer, softirq:... |
574 575 576 |
* The trampoline is called when the hrtimer expires. It schedules a tasklet * to run __tasklet_hrtimer_trampoline() which in turn will call the intended * hrtimer callback, but from softirq context. |
9ba5f005c softirq: introduc... |
577 578 579 580 581 |
*/ static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer) { struct tasklet_hrtimer *ttimer = container_of(timer, struct tasklet_hrtimer, timer); |
b9c303227 hrtimer, softirq:... |
582 583 |
tasklet_hi_schedule(&ttimer->tasklet); return HRTIMER_NORESTART; |
9ba5f005c softirq: introduc... |
584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 |
} /* * Helper function which calls the hrtimer callback from * tasklet/softirq context */ static void __tasklet_hrtimer_trampoline(unsigned long data) { struct tasklet_hrtimer *ttimer = (void *)data; enum hrtimer_restart restart; restart = ttimer->function(&ttimer->timer); if (restart != HRTIMER_NORESTART) hrtimer_restart(&ttimer->timer); } /** * tasklet_hrtimer_init - Init a tasklet/hrtimer combo for softirq callbacks * @ttimer: tasklet_hrtimer which is initialized |
25985edce Fix common misspe... |
603 |
* @function: hrtimer callback function which gets called from softirq context |
9ba5f005c softirq: introduc... |
604 605 606 607 608 609 610 611 612 613 614 615 616 617 |
* @which_clock: clock id (CLOCK_MONOTONIC/CLOCK_REALTIME) * @mode: hrtimer mode (HRTIMER_MODE_ABS/HRTIMER_MODE_REL) */ void tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer, enum hrtimer_restart (*function)(struct hrtimer *), clockid_t which_clock, enum hrtimer_mode mode) { hrtimer_init(&ttimer->timer, which_clock, mode); ttimer->timer.function = __hrtimer_tasklet_trampoline; tasklet_init(&ttimer->tasklet, __tasklet_hrtimer_trampoline, (unsigned long)ttimer); ttimer->function = function; } EXPORT_SYMBOL_GPL(tasklet_hrtimer_init); |
1da177e4c Linux-2.6.12-rc2 |
618 619 |
void __init softirq_init(void) { |
48f20a9a9 tasklets: execute... |
620 621 622 623 624 625 626 627 |
int cpu; for_each_possible_cpu(cpu) { per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head; per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head; } |
962cf36c5 Remove argument f... |
628 629 |
open_softirq(TASKLET_SOFTIRQ, tasklet_action); open_softirq(HI_SOFTIRQ, tasklet_hi_action); |
1da177e4c Linux-2.6.12-rc2 |
630 |
} |
3e339b5da softirq: Use hotp... |
631 |
static int ksoftirqd_should_run(unsigned int cpu) |
1da177e4c Linux-2.6.12-rc2 |
632 |
{ |
3e339b5da softirq: Use hotp... |
633 634 |
return local_softirq_pending(); } |
1da177e4c Linux-2.6.12-rc2 |
635 |
|
3e339b5da softirq: Use hotp... |
636 637 638 639 |
static void run_ksoftirqd(unsigned int cpu) { local_irq_disable(); if (local_softirq_pending()) { |
0bed698a3 irq: Justify the ... |
640 641 642 643 |
/* * We can safely run softirq on inline stack, as we are not deep * in the task stack here. */ |
3e339b5da softirq: Use hotp... |
644 |
__do_softirq(); |
3e339b5da softirq: Use hotp... |
645 |
local_irq_enable(); |
60479676e ksoftirqd: Use ne... |
646 |
cond_resched_rcu_qs(); |
3e339b5da softirq: Use hotp... |
647 |
return; |
1da177e4c Linux-2.6.12-rc2 |
648 |
} |
3e339b5da softirq: Use hotp... |
649 |
local_irq_enable(); |
1da177e4c Linux-2.6.12-rc2 |
650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 |
} #ifdef CONFIG_HOTPLUG_CPU /* * tasklet_kill_immediate is called to remove a tasklet which can already be * scheduled for execution on @cpu. * * Unlike tasklet_kill, this function removes the tasklet * _immediately_, even if the tasklet is in TASKLET_STATE_SCHED state. * * When this function is called, @cpu must be in the CPU_DEAD state. */ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu) { struct tasklet_struct **i; BUG_ON(cpu_online(cpu)); BUG_ON(test_bit(TASKLET_STATE_RUN, &t->state)); if (!test_bit(TASKLET_STATE_SCHED, &t->state)) return; /* CPU is dead, so no lock needed. */ |
48f20a9a9 tasklets: execute... |
673 |
for (i = &per_cpu(tasklet_vec, cpu).head; *i; i = &(*i)->next) { |
1da177e4c Linux-2.6.12-rc2 |
674 675 |
if (*i == t) { *i = t->next; |
48f20a9a9 tasklets: execute... |
676 677 678 |
/* If this was the tail element, move the tail ptr */ if (*i == NULL) per_cpu(tasklet_vec, cpu).tail = i; |
1da177e4c Linux-2.6.12-rc2 |
679 680 681 682 683 |
return; } } BUG(); } |
c4544dbc7 kernel/softirq: C... |
684 |
static int takeover_tasklets(unsigned int cpu) |
1da177e4c Linux-2.6.12-rc2 |
685 |
{ |
1da177e4c Linux-2.6.12-rc2 |
686 687 688 689 |
/* CPU is dead, so no lock needed. */ local_irq_disable(); /* Find end, append list for that CPU. */ |
e5e417232 Fix cpu hotplug p... |
690 |
if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) { |
909ea9646 core: Replace __g... |
691 692 |
*__this_cpu_read(tasklet_vec.tail) = per_cpu(tasklet_vec, cpu).head; this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail); |
e5e417232 Fix cpu hotplug p... |
693 694 695 |
per_cpu(tasklet_vec, cpu).head = NULL; per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head; } |
1da177e4c Linux-2.6.12-rc2 |
696 |
raise_softirq_irqoff(TASKLET_SOFTIRQ); |
e5e417232 Fix cpu hotplug p... |
697 |
if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) { |
909ea9646 core: Replace __g... |
698 699 |
*__this_cpu_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head; __this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail); |
e5e417232 Fix cpu hotplug p... |
700 701 702 |
per_cpu(tasklet_hi_vec, cpu).head = NULL; per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head; } |
1da177e4c Linux-2.6.12-rc2 |
703 704 705 |
raise_softirq_irqoff(HI_SOFTIRQ); local_irq_enable(); |
c4544dbc7 kernel/softirq: C... |
706 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
707 |
} |
c4544dbc7 kernel/softirq: C... |
708 709 |
#else #define takeover_tasklets NULL |
1da177e4c Linux-2.6.12-rc2 |
710 |
#endif /* CONFIG_HOTPLUG_CPU */ |
3e339b5da softirq: Use hotp... |
711 712 713 714 715 716 |
static struct smp_hotplug_thread softirq_threads = { .store = &ksoftirqd, .thread_should_run = ksoftirqd_should_run, .thread_fn = run_ksoftirqd, .thread_comm = "ksoftirqd/%u", }; |
7babe8db9 Full conversion t... |
717 |
static __init int spawn_ksoftirqd(void) |
1da177e4c Linux-2.6.12-rc2 |
718 |
{ |
c4544dbc7 kernel/softirq: C... |
719 720 |
cpuhp_setup_state_nocalls(CPUHP_SOFTIRQ_DEAD, "softirq:dead", NULL, takeover_tasklets); |
3e339b5da softirq: Use hotp... |
721 |
BUG_ON(smpboot_register_percpu_thread(&softirq_threads)); |
1da177e4c Linux-2.6.12-rc2 |
722 723 |
return 0; } |
7babe8db9 Full conversion t... |
724 |
early_initcall(spawn_ksoftirqd); |
78eef01b0 [PATCH] on_each_c... |
725 |
|
43a256322 sparseirq: move _... |
726 727 728 729 730 731 732 733 734 |
/* * [ These __weak aliases are kept in a separate compilation unit, so that * GCC does not inline them incorrectly. ] */ int __init __weak early_irq_init(void) { return 0; } |
4a046d175 x86: arch_probe_n... |
735 736 |
int __init __weak arch_probe_nr_irqs(void) { |
b683de2b3 genirq: Query arc... |
737 |
return NR_IRQS_LEGACY; |
4a046d175 x86: arch_probe_n... |
738 |
} |
43a256322 sparseirq: move _... |
739 740 741 742 |
int __init __weak arch_early_irq_init(void) { return 0; } |
62a08ae2a genirq: x86: Ensu... |
743 744 745 746 747 |
unsigned int __weak arch_dynirq_lower_bound(unsigned int from) { return from; } |