From 244b2c5ca8b14627e4a17755e5922221e121c771 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 09 Oct 2024 06:15:07 +0000
Subject: [PATCH] change system file
---
kernel/kernel/softirq.c | 210 ++++++++++++++++++++++++++++------------------------
1 files changed, 114 insertions(+), 96 deletions(-)
diff --git a/kernel/kernel/softirq.c b/kernel/kernel/softirq.c
index 6f58486..d59412b 100644
--- a/kernel/kernel/softirq.c
+++ b/kernel/kernel/softirq.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/kernel/softirq.c
*
* Copyright (C) 1992 Linus Torvalds
- *
- * Distribute under GPLv2.
*
* Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903)
*/
@@ -29,6 +28,9 @@
#define CREATE_TRACE_POINTS
#include <trace/events/irq.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(irq_handler_entry);
+EXPORT_TRACEPOINT_SYMBOL_GPL(irq_handler_exit);
/*
- No shared variables, all the data are CPU local.
@@ -56,6 +58,14 @@
static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp;
DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
+EXPORT_PER_CPU_SYMBOL_GPL(ksoftirqd);
+
+/*
+ * active_softirqs -- per cpu, a mask of softirqs that are being handled,
+ * with the expectation that approximate answers are acceptable and therefore
+ * no synchronization.
+ */
+DEFINE_PER_CPU(__u32, active_softirqs);
const char * const softirq_to_name[NR_SOFTIRQS] = {
"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "IRQ_POLL",
@@ -78,21 +88,6 @@
}
/*
- * 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,
- * unless we're doing some of the synchronous softirqs.
- */
-#define SOFTIRQ_NOW_MASK ((1 << HI_SOFTIRQ) | (1 << TASKLET_SOFTIRQ))
-static bool ksoftirqd_running(unsigned long pending)
-{
- struct task_struct *tsk = __this_cpu_read(ksoftirqd);
-
- if (pending & SOFTIRQ_NOW_MASK)
- return false;
- return tsk && (tsk->state == TASK_RUNNING);
-}
-
-/*
* preempt_count and SOFTIRQ_OFFSET usage:
* - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
* softirq processing.
@@ -107,6 +102,12 @@
* where hardirqs are disabled legitimately:
*/
#ifdef CONFIG_TRACE_IRQFLAGS
+
+DEFINE_PER_CPU(int, hardirqs_enabled);
+DEFINE_PER_CPU(int, hardirq_context);
+EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled);
+EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context);
+
void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
{
unsigned long flags;
@@ -126,7 +127,7 @@
* Were softirqs turned off above:
*/
if (softirq_count() == (cnt & SOFTIRQ_MASK))
- trace_softirqs_off(ip);
+ lockdep_softirqs_off(ip);
raw_local_irq_restore(flags);
if (preempt_count() == cnt) {
@@ -147,7 +148,7 @@
trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
if (softirq_count() == (cnt & SOFTIRQ_MASK))
- trace_softirqs_on(_RET_IP_);
+ lockdep_softirqs_on(_RET_IP_);
__preempt_count_sub(cnt);
}
@@ -174,7 +175,7 @@
* Are softirqs going to be turned on now:
*/
if (softirq_count() == SOFTIRQ_DISABLE_OFFSET)
- trace_softirqs_on(ip);
+ lockdep_softirqs_on(ip);
/*
* Keep preemption disabled until we are done with
* softirq processing:
@@ -224,9 +225,9 @@
{
bool in_hardirq = false;
- if (trace_hardirq_context(current)) {
+ if (lockdep_hardirq_context()) {
in_hardirq = true;
- trace_hardirq_exit();
+ lockdep_hardirq_exit();
}
lockdep_softirq_enter();
@@ -239,12 +240,22 @@
lockdep_softirq_exit();
if (in_hardirq)
- trace_hardirq_enter();
+ lockdep_hardirq_enter();
}
#else
static inline bool lockdep_softirq_start(void) { return false; }
static inline void lockdep_softirq_end(bool in_hardirq) { }
#endif
+
+#define softirq_deferred_for_rt(pending) \
+({ \
+ __u32 deferred = 0; \
+ if (cpupri_check_rt()) { \
+ deferred = pending & LONG_SOFTIRQ_MASK; \
+ pending &= ~LONG_SOFTIRQ_MASK; \
+ } \
+ deferred; \
+})
asmlinkage __visible void __softirq_entry __do_softirq(void)
{
@@ -253,25 +264,27 @@
int max_restart = MAX_SOFTIRQ_RESTART;
struct softirq_action *h;
bool in_hardirq;
+ __u32 deferred;
__u32 pending;
int softirq_bit;
/*
- * 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
+ * Mask out PF_MEMALLOC as the 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 swapping.
*/
current->flags &= ~PF_MEMALLOC;
pending = local_softirq_pending();
+ deferred = softirq_deferred_for_rt(pending);
account_irq_enter_time(current);
-
__local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
in_hardirq = lockdep_softirq_start();
restart:
/* Reset the pending bitmask before enabling irqs */
- set_softirq_pending(0);
+ set_softirq_pending(deferred);
+ __this_cpu_write(active_softirqs, pending);
local_irq_enable();
@@ -301,18 +314,28 @@
pending >>= softirq_bit;
}
- rcu_bh_qs();
+ __this_cpu_write(active_softirqs, 0);
+ if (__this_cpu_read(ksoftirqd) == current)
+ rcu_softirq_qs();
local_irq_disable();
pending = local_softirq_pending();
+ deferred = softirq_deferred_for_rt(pending);
+
if (pending) {
if (time_before(jiffies, end) && !need_resched() &&
--max_restart)
goto restart;
+#ifndef CONFIG_RT_SOFTINT_OPTIMIZATION
wakeup_softirqd();
+#endif
}
+#ifdef CONFIG_RT_SOFTINT_OPTIMIZATION
+ if (pending | deferred)
+ wakeup_softirqd();
+#endif
lockdep_softirq_end(in_hardirq);
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
@@ -332,18 +355,17 @@
pending = local_softirq_pending();
- if (pending && !ksoftirqd_running(pending))
+ if (pending)
do_softirq_own_stack();
local_irq_restore(flags);
}
-/*
- * Enter an interrupt context.
+/**
+ * irq_enter_rcu - Enter an interrupt context with RCU watching
*/
-void irq_enter(void)
+void irq_enter_rcu(void)
{
- rcu_irq_enter();
if (is_idle_task(current) && !in_interrupt()) {
/*
* Prevent raise_softirq from needlessly waking up ksoftirqd
@@ -353,15 +375,20 @@
tick_irq_enter();
_local_bh_enable();
}
-
__irq_enter();
+}
+
+/**
+ * irq_enter - Enter an interrupt context including RCU update
+ */
+void irq_enter(void)
+{
+ rcu_irq_enter();
+ irq_enter_rcu();
}
static inline void invoke_softirq(void)
{
- if (ksoftirqd_running(local_softirq_pending()))
- return;
-
if (!force_irqthreads) {
#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
/*
@@ -396,10 +423,7 @@
#endif
}
-/*
- * Exit an interrupt context. Process softirqs if needed and possible:
- */
-void irq_exit(void)
+static inline void __irq_exit_rcu(void)
{
#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED
local_irq_disable();
@@ -412,8 +436,31 @@
invoke_softirq();
tick_irq_exit();
+}
+
+/**
+ * irq_exit_rcu() - Exit an interrupt context without updating RCU
+ *
+ * Also processes softirqs if needed and possible.
+ */
+void irq_exit_rcu(void)
+{
+ __irq_exit_rcu();
+ /* must be last! */
+ lockdep_hardirq_exit();
+}
+
+/**
+ * irq_exit - Exit an interrupt context, update RCU and lockdep
+ *
+ * Also processes softirqs if needed and possible.
+ */
+void irq_exit(void)
+{
+ __irq_exit_rcu();
rcu_irq_exit();
- trace_hardirq_exit(); /* must be last! */
+ /* must be last! */
+ lockdep_hardirq_exit();
}
/*
@@ -447,6 +494,7 @@
void __raise_softirq_irqoff(unsigned int nr)
{
+ lockdep_assert_irqs_disabled();
trace_softirq_raise(nr);
or_softirq_pending(1UL << nr);
}
@@ -519,7 +567,15 @@
if (!test_and_clear_bit(TASKLET_STATE_SCHED,
&t->state))
BUG();
- t->func(t->data);
+ if (t->use_callback) {
+ trace_tasklet_entry(t->callback);
+ t->callback(t);
+ trace_tasklet_exit(t->callback);
+ } else {
+ trace_tasklet_entry(t->func);
+ t->func(t->data);
+ trace_tasklet_exit(t->func);
+ }
tasklet_unlock(t);
continue;
}
@@ -545,6 +601,18 @@
tasklet_action_common(a, this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ);
}
+void tasklet_setup(struct tasklet_struct *t,
+ void (*callback)(struct tasklet_struct *))
+{
+ t->next = NULL;
+ t->state = 0;
+ atomic_set(&t->count, 0);
+ t->callback = callback;
+ t->use_callback = true;
+ t->data = 0;
+}
+EXPORT_SYMBOL(tasklet_setup);
+
void tasklet_init(struct tasklet_struct *t,
void (*func)(unsigned long), unsigned long data)
{
@@ -552,6 +620,7 @@
t->state = 0;
atomic_set(&t->count, 0);
t->func = func;
+ t->use_callback = false;
t->data = data;
}
EXPORT_SYMBOL(tasklet_init);
@@ -570,57 +639,6 @@
clear_bit(TASKLET_STATE_SCHED, &t->state);
}
EXPORT_SYMBOL(tasklet_kill);
-
-/*
- * tasklet_hrtimer
- */
-
-/*
- * 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.
- */
-static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
-{
- struct tasklet_hrtimer *ttimer =
- container_of(timer, struct tasklet_hrtimer, timer);
-
- tasklet_hi_schedule(&ttimer->tasklet);
- return HRTIMER_NORESTART;
-}
-
-/*
- * 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
- * @function: hrtimer callback function which gets called from softirq context
- * @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);
void __init softirq_init(void)
{
@@ -699,7 +717,7 @@
/* Find end, append list for that CPU. */
if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) {
*__this_cpu_read(tasklet_vec.tail) = per_cpu(tasklet_vec, cpu).head;
- this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail);
+ __this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail);
per_cpu(tasklet_vec, cpu).head = NULL;
per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head;
}
--
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