Re: [RFC 4/7] LTTng instrumentation kernel

From: Mike Mason
Date: Thu Nov 15 2007 - 18:31:17 EST

This patch uses _trace_mark in lockdep.c and printk.c. I assume they should be trace_mark (no '_' prefix).

Mike Mason


Mathieu Desnoyers wrote:

Core kernel events.

*not* present in this patch because they are architecture specific :
- syscall entry/exit
- traps
- kernel thread creation

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
---
include/linux/module.h | 1 +
kernel/exit.c | 5 +++++
kernel/fork.c | 4 ++++
kernel/irq/handle.c | 6 ++++++
kernel/itimer.c | 11 +++++++++++
kernel/kthread.c | 4 ++++
kernel/lockdep.c | 19 +++++++++++++++++++
kernel/module.c | 25 +++++++++++++++++++++++++
kernel/printk.c | 26 ++++++++++++++++++++++++++
kernel/sched.c | 11 +++++++++++
kernel/signal.c | 2 ++
kernel/softirq.c | 22 ++++++++++++++++++++++
kernel/timer.c | 12 +++++++++++-
13 files changed, 147 insertions(+), 1 deletion(-)

Index: linux-2.6-lttng/kernel/irq/handle.c
===================================================================
--- linux-2.6-lttng.orig/kernel/irq/handle.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/irq/handle.c 2007-11-13 09:49:33.000000000 -0500
@@ -130,6 +130,10 @@ irqreturn_t handle_IRQ_event(unsigned in
{
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
+ struct pt_regs *regs = get_irq_regs();
+
+ trace_mark(kernel_irq_entry, "irq_id %u kernel_mode %u", irq,
+ (regs)?(!user_mode(regs)):(1));

handle_dynamic_tick(action);

@@ -148,6 +152,8 @@ irqreturn_t handle_IRQ_event(unsigned in
add_interrupt_randomness(irq);
local_irq_disable();

+ trace_mark(kernel_irq_exit, MARK_NOARGS);
+
return retval;
}

Index: linux-2.6-lttng/kernel/itimer.c
===================================================================
--- linux-2.6-lttng.orig/kernel/itimer.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/itimer.c 2007-11-13 09:49:33.000000000 -0500
@@ -132,6 +132,8 @@ enum hrtimer_restart it_real_fn(struct h
struct signal_struct *sig =
container_of(timer, struct signal_struct, real_timer);

+ trace_mark(kernel_timer_itimer_expired, "pid %d", sig->tsk->pid);
+
send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);

return HRTIMER_NORESTART;
@@ -157,6 +159,15 @@ int do_setitimer(int which, struct itime
!timeval_valid(&value->it_interval))
return -EINVAL;

+ trace_mark(kernel_timer_itimer_set,
+ "which %d interval_sec %ld interval_usec %ld "
+ "value_sec %ld value_usec %ld",
+ which,
+ value->it_interval.tv_sec,
+ value->it_interval.tv_usec,
+ value->it_value.tv_sec,
+ value->it_value.tv_usec);
+
switch (which) {
case ITIMER_REAL:
again:
Index: linux-2.6-lttng/kernel/kthread.c
===================================================================
--- linux-2.6-lttng.orig/kernel/kthread.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/kthread.c 2007-11-13 09:49:33.000000000 -0500
@@ -195,6 +195,8 @@ int kthread_stop(struct task_struct *k)
/* It could exit after stop_info.k set, but before wake_up_process. */
get_task_struct(k);

+ trace_mark(kernel_kthread_stop, "pid %d", k->pid);
+
/* Must init completion *before* thread sees kthread_stop_info.k */
init_completion(&kthread_stop_info.done);
smp_wmb();
@@ -210,6 +212,8 @@ int kthread_stop(struct task_struct *k)
ret = kthread_stop_info.err;
mutex_unlock(&kthread_stop_lock);

+ trace_mark(kernel_kthread_stop_ret, "ret %d", ret);
+
return ret;
}
EXPORT_SYMBOL(kthread_stop);
Index: linux-2.6-lttng/kernel/lockdep.c
===================================================================
--- linux-2.6-lttng.orig/kernel/lockdep.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/lockdep.c 2007-11-13 09:49:33.000000000 -0500
@@ -2014,6 +2014,9 @@ void trace_hardirqs_on(void)
struct task_struct *curr = current;
unsigned long ip;

+ _trace_mark(locking_hardirqs_on, "ip #p%lu",
+ (unsigned long) __builtin_return_address(0));
+
if (unlikely(!debug_locks || current->lockdep_recursion))
return;

@@ -2061,6 +2064,9 @@ void trace_hardirqs_off(void)
{
struct task_struct *curr = current;

+ _trace_mark(locking_hardirqs_off, "ip #p%lu",
+ (unsigned long) __builtin_return_address(0));
+
if (unlikely(!debug_locks || current->lockdep_recursion))
return;

@@ -2088,6 +2094,9 @@ void trace_softirqs_on(unsigned long ip)
{
struct task_struct *curr = current;

+ _trace_mark(locking_softirqs_on, "ip #p%lu",
+ (unsigned long) __builtin_return_address(0));
+
if (unlikely(!debug_locks))
return;

@@ -2122,6 +2131,9 @@ void trace_softirqs_off(unsigned long ip
{
struct task_struct *curr = current;

+ _trace_mark(locking_softirqs_off, "ip #p%lu",
+ (unsigned long) __builtin_return_address(0));
+
if (unlikely(!debug_locks))
return;

@@ -2358,6 +2370,10 @@ static int __lock_acquire(struct lockdep
int chain_head = 0;
u64 chain_key;

+ _trace_mark(locking_lock_acquire,
+ "ip #p%lu subclass %u lock %p trylock %d",
+ ip, subclass, lock, trylock);
+
if (!prove_locking)
check = 1;

@@ -2631,6 +2647,9 @@ __lock_release(struct lockdep_map *lock,
{
struct task_struct *curr = current;

+ _trace_mark(locking_lock_release, "ip #p%lu lock %p nested %d",
+ ip, lock, nested);
+
if (!check_unlock(curr, lock, ip))
return;

Index: linux-2.6-lttng/kernel/printk.c
===================================================================
--- linux-2.6-lttng.orig/kernel/printk.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/printk.c 2007-11-13 09:49:33.000000000 -0500
@@ -619,6 +619,7 @@ asmlinkage int printk(const char *fmt, .
int r;

va_start(args, fmt);
+ trace_mark(kernel_printk, "ip %p", __builtin_return_address(0));
r = vprintk(fmt, args);
va_end(args);

@@ -653,6 +654,31 @@ asmlinkage int vprintk(const char *fmt, /* Emit the output into the temporary buffer */
printed_len = vscnprintf(printk_buf, sizeof(printk_buf), fmt, args);

+ if (printed_len > 0) {
+ unsigned int loglevel;
+ int mark_len;
+ char *mark_buf;
+ char saved_char;
+
+ if (printk_buf[0] == '<' && printk_buf[1] >= '0' &&
+ printk_buf[1] <= '7' && printk_buf[2] == '>') {
+ loglevel = printk_buf[1] - '0';
+ mark_buf = &printk_buf[3];
+ mark_len = printed_len - 3;
+ } else {
+ loglevel = default_message_loglevel;
+ mark_buf = printk_buf;
+ mark_len = printed_len;
+ }
+ if (mark_buf[mark_len - 1] == '\n')
+ mark_len--;
+ saved_char = mark_buf[mark_len];
+ mark_buf[mark_len] = '\0';
+ _trace_mark(kernel_vprintk, "loglevel %c string %s ip %p",
+ loglevel, mark_buf, __builtin_return_address(0));
+ mark_buf[mark_len] = saved_char;
+ }
+
/*
* Copy the output into log_buf. If the caller didn't provide
* appropriate log level tags, we insert them here
Index: linux-2.6-lttng/kernel/sched.c
===================================================================
--- linux-2.6-lttng.orig/kernel/sched.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/sched.c 2007-11-13 09:49:33.000000000 -0500
@@ -1161,6 +1161,8 @@ void wait_task_inactive(struct task_stru
* just go back and repeat.
*/
rq = task_rq_lock(p, &flags);
+ trace_mark(kernel_sched_wait_task, "pid %d state %ld",
+ p->pid, p->state);
running = task_running(rq, p);
on_rq = p->se.on_rq;
task_rq_unlock(rq, &flags);
@@ -1495,6 +1497,8 @@ static int try_to_wake_up(struct task_st
#endif

rq = task_rq_lock(p, &flags);
+ trace_mark(kernel_sched_try_wakeup, "pid %d state %ld",
+ p->pid, p->state);
old_state = p->state;
if (!(old_state & state))
goto out;
@@ -1733,6 +1737,8 @@ void fastcall wake_up_new_task(struct ta
struct rq *rq;

rq = task_rq_lock(p, &flags);
+ trace_mark(kernel_sched_wakeup_new_task, "pid %d state %ld",
+ p->pid, p->state);
BUG_ON(p->state != TASK_RUNNING);
update_rq_clock(rq);

@@ -1911,6 +1917,9 @@ context_switch(struct rq *rq, struct tas
struct mm_struct *mm, *oldmm;

prepare_task_switch(rq, prev, next);
+ trace_mark(kernel_sched_schedule,
+ "prev_pid %d next_pid %d prev_state %ld",
+ prev->pid, next->pid, prev->state);
mm = next->mm;
oldmm = prev->active_mm;
/*
@@ -2139,6 +2148,8 @@ static void sched_migrate_task(struct ta
|| unlikely(cpu_is_offline(dest_cpu)))
goto out;

+ trace_mark(kernel_sched_migrate_task, "pid %d state %ld dest_cpu %d",
+ p->pid, p->state, dest_cpu);
/* force the process onto the specified CPU */
if (migrate_task(p, dest_cpu, &req)) {
/* Need to wait for migration thread (might exit: take ref). */
Index: linux-2.6-lttng/kernel/signal.c
===================================================================
--- linux-2.6-lttng.orig/kernel/signal.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/signal.c 2007-11-13 09:49:33.000000000 -0500
@@ -663,6 +663,8 @@ static int send_signal(int sig, struct s
struct sigqueue * q = NULL;
int ret = 0;

+ trace_mark(kernel_send_signal, "pid %d signal %d", t->pid, sig);
+
/*
* Deliver the signal to listening signalfds. This must be called
* with the sighand lock held.
Index: linux-2.6-lttng/kernel/softirq.c
===================================================================
--- linux-2.6-lttng.orig/kernel/softirq.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/softirq.c 2007-11-13 09:49:33.000000000 -0500
@@ -229,7 +229,15 @@ restart:

do {
if (pending & 1) {
+ trace_mark(kernel_softirq_entry, "softirq_id %lu",
+ ((unsigned long)h
+ - (unsigned long)softirq_vec)
+ / sizeof(*h));
h->action(h);
+ trace_mark(kernel_softirq_exit, "softirq_id %lu",
+ ((unsigned long)h
+ - (unsigned long)softirq_vec)
+ / sizeof(*h));
rcu_bh_qsctr_inc(cpu);
}
h++;
@@ -315,6 +323,8 @@ void irq_exit(void)
*/
inline fastcall void raise_softirq_irqoff(unsigned int nr)
{
+ trace_mark(kernel_softirq_raise, "softirq %u", nr);
+
__raise_softirq_irqoff(nr);

/*
@@ -400,7 +410,13 @@ static void tasklet_action(struct softir
if (!atomic_read(&t->count)) {
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
BUG();
+ trace_mark(kernel_tasklet_low_entry,
+ "func %p data %lu",
+ t->func, t->data);
t->func(t->data);
+ trace_mark(kernel_tasklet_low_exit,
+ "func %p data %lu",
+ t->func, t->data);
tasklet_unlock(t);
continue;
}
@@ -433,7 +449,13 @@ static void tasklet_hi_action(struct sof
if (!atomic_read(&t->count)) {
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
BUG();
+ trace_mark(kernel_tasklet_high_entry,
+ "func %p data %lu",
+ t->func, t->data);
t->func(t->data);
+ trace_mark(kernel_tasklet_high_exit,
+ "func %p data %lu",
+ t->func, t->data);
tasklet_unlock(t);
continue;
}
Index: linux-2.6-lttng/kernel/timer.c
===================================================================
--- linux-2.6-lttng.orig/kernel/timer.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/timer.c 2007-11-13 09:49:33.000000000 -0500
@@ -43,6 +43,7 @@
#include <asm/div64.h>
#include <asm/timex.h>
#include <asm/io.h>
+#include <asm/irq_regs.h>

u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;

@@ -290,6 +291,8 @@ static void internal_add_timer(tvec_base
i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
vec = base->tv5.vec + i;
}
+ trace_mark(kernel_timer_set, "expires %lu function %p data %lu",
+ expires, timer->function, timer->data);
/*
* Timers are FIFO:
*/
@@ -931,6 +934,11 @@ void do_timer(unsigned long ticks)
{
jiffies_64 += ticks;
update_times(ticks);
+ trace_mark(kernel_timer_update_time,
+ "jiffies #8u%llu xtime_sec %ld xtime_nsec %ld "
+ "walltomonotonic_sec %ld walltomonotonic_nsec %ld",
+ jiffies_64, xtime.tv_sec, xtime.tv_nsec,
+ wall_to_monotonic.tv_sec, wall_to_monotonic.tv_nsec);
}

#ifdef __ARCH_WANT_SYS_ALARM
@@ -1012,7 +1020,9 @@ asmlinkage long sys_getegid(void)

static void process_timeout(unsigned long __data)
{
- wake_up_process((struct task_struct *)__data);
+ struct task_struct *task = (struct task_struct *)__data;
+ trace_mark(kernel_timer_timeout, "pid %d", task->pid);
+ wake_up_process(task);
}

/**
Index: linux-2.6-lttng/kernel/exit.c
===================================================================
--- linux-2.6-lttng.orig/kernel/exit.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/exit.c 2007-11-13 09:49:33.000000000 -0500
@@ -177,6 +177,7 @@ repeat:

write_unlock_irq(&tasklist_lock);
release_thread(p);
+ trace_mark(kernel_process_free, "pid %d", p->pid);
call_rcu(&p->rcu, delayed_put_task_struct);

p = leader;
@@ -994,6 +995,8 @@ fastcall NORET_TYPE void do_exit(long co

if (group_dead)
acct_process();
+ trace_mark(kernel_process_exit, "pid %d", tsk->pid);
+
exit_sem(tsk);
__exit_files(tsk);
__exit_fs(tsk);
@@ -1539,6 +1542,8 @@ static long do_wait(pid_t pid, int optio
int flag, retval;
int allowed, denied;

+ trace_mark(kernel_process_wait, "pid %d", pid);
+
add_wait_queue(&current->signal->wait_chldexit,&wait);
repeat:
/*
Index: linux-2.6-lttng/kernel/fork.c
===================================================================
--- linux-2.6-lttng.orig/kernel/fork.c 2007-11-13 09:25:27.000000000 -0500
+++ linux-2.6-lttng/kernel/fork.c 2007-11-13 09:49:33.000000000 -0500
@@ -1435,6 +1435,10 @@ long do_fork(unsigned long clone_flags,
if (!IS_ERR(p)) {
struct completion vfork;

+ trace_mark(kernel_process_fork,
+ "parent_pid %d child_pid %d child_tgid %d",
+ current->pid, p->pid, p->tgid);
+
/*
* this is enough to call pid_nr_ns here, but this if
* improves optimisation of regular fork()
Index: linux-2.6-lttng/include/linux/module.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/module.h 2007-11-13 09:48:41.000000000 -0500
+++ linux-2.6-lttng/include/linux/module.h 2007-11-13 09:49:33.000000000 -0500
@@ -466,6 +466,7 @@ int register_module_notifier(struct noti
int unregister_module_notifier(struct notifier_block * nb);

extern void print_modules(void);
+extern void list_modules(void *call_data);

extern void module_update_markers(void);

Index: linux-2.6-lttng/kernel/module.c
===================================================================
--- linux-2.6-lttng.orig/kernel/module.c 2007-11-13 09:49:16.000000000 -0500
+++ linux-2.6-lttng/kernel/module.c 2007-11-13 09:49:33.000000000 -0500
@@ -1294,6 +1294,8 @@ static int __unlink_module(void *_mod)
/* Free a module, remove from lists, etc (must hold module_mutex). */
static void free_module(struct module *mod)
{
+ trace_mark(kernel_module_free, "name %s", mod->name);
+
/* Delete from various lists */
stop_machine_run(__unlink_module, mod, NR_CPUS);
remove_notes_attrs(mod);
@@ -2063,6 +2065,8 @@ static struct module *load_module(void _
/* Get rid of temporary copy */
vfree(hdr);

+ trace_mark(kernel_module_load, "name %s", mod->name);
+
/* Done! */
return mod;

@@ -2426,6 +2430,27 @@ const struct seq_operations modules_op =
.show = m_show
};

+void list_modules(void *call_data)
+{
+ /* Enumerate loaded modules */
+ struct list_head *i;
+ struct module *mod;
+ unsigned long refcount = 0;
+
+ mutex_lock(&module_mutex);
+ list_for_each(i, &modules) {
+ mod = list_entry(i, struct module, list);
+#ifdef CONFIG_MODULE_UNLOAD
+ refcount = local_read(&mod->ref[0].count);
+#endif
+ __trace_mark(0, list_module, call_data,
+ "name %s state %d refcount %lu",
+ mod->name, mod->state, refcount);
+ }
+ mutex_unlock(&module_mutex);
+}
+EXPORT_SYMBOL_GPL(list_modules);
+
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{

-- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ -
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