Re: [GIT] merge conflicts of tip/tracing/core and latest perf/core

From: Steven Rostedt
Date: Fri May 21 2010 - 10:42:35 EST

On Fri, 2010-05-21 at 10:30 -0400, Steven Rostedt wrote:
> Once again I resolved the conflicts between tracing/core and the new
> changes of perf/core.
>
> Here's the diff, can you please give acks.

For those that can't read git conflict diffs. Here's the:

git diff HEAD

Which shows all of Peter's changes + mine on top. I only included the
files that conflicted:

# Changed but not updated:
# (use "git add <file>..." to update what will be committed)
# (use "git checkout -- <file>..." to discard changes in working directory)
#
# unmerged: include/linux/ftrace_event.h
# unmerged: include/trace/ftrace.h
# unmerged: kernel/trace/trace_event_perf.c
# unmerged: kernel/trace/trace_kprobe.c
# unmerged: kernel/trace/trace_syscalls.c
#


Note, I did add the #ifdef CONFIG_PERF_EVENTS in the event structure.

-- Steve

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index dc7fc64..ee8a841 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -180,7 +180,10 @@ struct ftrace_event_call {
*/
unsigned int flags;

+#ifdef CONFIG_PERF_EVENTS
int perf_refcount;
+ struct hlist_head *perf_events;
+#endif
};

#define PERF_MAX_TRACE_SIZE 2048
@@ -237,24 +240,22 @@ struct perf_event;

DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);

-extern int perf_trace_enable(int event_id);
-extern void perf_trace_disable(int event_id);
-extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
+extern int perf_trace_init(struct perf_event *event);
+extern void perf_trace_destroy(struct perf_event *event);
+extern int perf_trace_enable(struct perf_event *event);
+extern void perf_trace_disable(struct perf_event *event);
+extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
char *filter_str);
extern void ftrace_profile_free_filter(struct perf_event *event);
-extern void *
-perf_trace_buf_prepare(int size, unsigned short type, int *rctxp,
- unsigned long *irq_flags);
+extern void *perf_trace_buf_prepare(int size, unsigned short type,
+ struct pt_regs *regs, int *rctxp);

static inline void
perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
- u64 count, unsigned long irq_flags, struct pt_regs *regs)
+ u64 count, struct pt_regs *regs, void *head)
{
- struct trace_entry *entry = raw_data;
-
- perf_tp_event(entry->type, addr, count, raw_data, size, regs);
+ perf_tp_event(addr, count, raw_data, size, regs, head);
perf_swevent_put_recursion_context(rctx);
- local_irq_restore(irq_flags);
}
#endif

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index e0e8daa..0152b86 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -695,14 +695,14 @@ perf_trace_##call(void *__data, proto) \
struct ftrace_event_call *event_call = __data; \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
struct ftrace_raw_##call *entry; \
- struct pt_regs *__regs = &get_cpu_var(perf_trace_regs); \
+ struct pt_regs __regs; \
u64 __addr = 0, __count = 1; \
- unsigned long irq_flags; \
+ struct hlist_head *head; \
int __entry_size; \
int __data_size; \
int rctx; \
\
- perf_fetch_caller_regs(__regs, 1); \
+ perf_fetch_caller_regs(&__regs, 1); \
\
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
@@ -711,19 +711,20 @@ perf_trace_##call(void *__data, proto) \
\
if (WARN_ONCE(__entry_size > PERF_MAX_TRACE_SIZE, \
"profile buffer not large enough")) \
- goto out; \
+ return; \
+ \
entry = (struct ftrace_raw_##call *)perf_trace_buf_prepare( \
- __entry_size, event_call->event.type, &rctx, &irq_flags); \
+ __entry_size, event_call->event.type, &__regs, &rctx); \
if (!entry) \
- goto out; \
+ return; \
+ \
tstruct \
\
{ assign; } \
\
+ head = per_cpu_ptr(event_call->perf_events, smp_processor_id());\
perf_trace_buf_submit(entry, __entry_size, rctx, __addr, \
- __count, irq_flags, __regs); \
- out: \
- put_cpu_var(perf_trace_regs); \
+ __count, &__regs, head); \
}

/*
@@ -736,7 +737,6 @@ perf_trace_##call(void *__data, proto) \
static inline void perf_test_probe_##call(void) \
{ \
check_trace_callback_type_##call(perf_trace_##template); \
- \
}


diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 0a47e8d..26b8607 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -9,13 +9,9 @@
#include <linux/kprobes.h>
#include "trace.h"

-DEFINE_PER_CPU(struct pt_regs, perf_trace_regs);
-EXPORT_PER_CPU_SYMBOL_GPL(perf_trace_regs);
-
EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs);

-static char *perf_trace_buf;
-static char *perf_trace_buf_nmi;
+static char *perf_trace_buf[4];

/*
* Force it to be aligned to unsigned long to avoid misaligned accesses
@@ -27,63 +23,82 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
/* Count the events in use (per event id, not per instance) */
static int total_ref_count;

-static int perf_trace_event_enable(struct ftrace_event_call *event)
+static int perf_trace_event_init(struct ftrace_event_call *tp_event,
+ struct perf_event *p_event)
{
- char *buf;
+ struct hlist_head *list;
int ret = -ENOMEM;
+ int cpu;

- if (event->perf_refcount++ > 0)
+ p_event->tp_event = tp_event;
+ if (tp_event->perf_refcount++ > 0)
return 0;

- if (!total_ref_count) {
- buf = (char *)alloc_percpu(perf_trace_t);
- if (!buf)
- goto fail_buf;
+ list = alloc_percpu(struct hlist_head);
+ if (!list)
+ goto fail;
+
+ for_each_possible_cpu(cpu)
+ INIT_HLIST_HEAD(per_cpu_ptr(list, cpu));

- rcu_assign_pointer(perf_trace_buf, buf);
+ tp_event->perf_events = list;
+
+ if (!total_ref_count) {
+ char *buf;
+ int i;

- buf = (char *)alloc_percpu(perf_trace_t);
- if (!buf)
- goto fail_buf_nmi;
+ for (i = 0; i < 4; i++) {
+ buf = (char *)alloc_percpu(perf_trace_t);
+ if (!buf)
+ goto fail;

- rcu_assign_pointer(perf_trace_buf_nmi, buf);
+ perf_trace_buf[i] = buf;
+ }
}

- if (event->class->reg)
- ret = event->class->reg(event, TRACE_REG_PERF_REGISTER);
+ if (tp_event->class->reg)
+ ret = tp_event->class->reg(tp_event, TRACE_REG_PERF_REGISTER);
else
- ret = tracepoint_probe_register(event->name,
- event->class->perf_probe,
- event);
- if (!ret) {
- total_ref_count++;
- return 0;
- }
+ ret = tracepoint_probe_register(tp_event->name,
+ tp_event->class->perf_probe,
+ tp_event);
+
+ if (ret)
+ goto fail;

-fail_buf_nmi:
+ total_ref_count++;
+ return 0;
+
+fail:
if (!total_ref_count) {
- free_percpu(perf_trace_buf_nmi);
- free_percpu(perf_trace_buf);
- perf_trace_buf_nmi = NULL;
- perf_trace_buf = NULL;
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ free_percpu(perf_trace_buf[i]);
+ perf_trace_buf[i] = NULL;
+ }
+ }
+
+ if (!--tp_event->perf_refcount) {
+ free_percpu(tp_event->perf_events);
+ tp_event->perf_events = NULL;
}
-fail_buf:
- event->perf_refcount--;

return ret;
}

-int perf_trace_enable(int event_id)
+int perf_trace_init(struct perf_event *p_event)
{
- struct ftrace_event_call *event;
+ struct ftrace_event_call *tp_event;
+ int event_id = p_event->attr.config;
int ret = -EINVAL;

mutex_lock(&event_mutex);
- list_for_each_entry(event, &ftrace_events, list) {
- if (event->event.type == event_id &&
- event->class && event->class->perf_probe &&
- try_module_get(event->mod)) {
- ret = perf_trace_event_enable(event);
+ list_for_each_entry(tp_event, &ftrace_events, list) {
+ if (tp_event->event.type == event_id &&
+ tp_event->class && tp_event->class->perf_probe &&
+ try_module_get(tp_event->mod)) {
+ ret = perf_trace_event_init(tp_event, p_event);
break;
}
}
@@ -92,93 +107,76 @@ int perf_trace_enable(int event_id)
return ret;
}

-static void perf_trace_event_disable(struct ftrace_event_call *event)
+int perf_trace_enable(struct perf_event *p_event)
{
- char *buf, *nmi_buf;
-
- if (--event->perf_refcount > 0)
- return;
-
- if (event->class->reg)
- event->class->reg(event, TRACE_REG_PERF_UNREGISTER);
- else
- tracepoint_probe_unregister(event->name, event->class->perf_probe, event);
+ struct ftrace_event_call *tp_event = p_event->tp_event;
+ struct hlist_head *list;

- if (!--total_ref_count) {
- buf = perf_trace_buf;
- rcu_assign_pointer(perf_trace_buf, NULL);
+ list = tp_event->perf_events;
+ if (WARN_ON_ONCE(!list))
+ return -EINVAL;

- nmi_buf = perf_trace_buf_nmi;
- rcu_assign_pointer(perf_trace_buf_nmi, NULL);
+ list = per_cpu_ptr(list, smp_processor_id());
+ hlist_add_head_rcu(&p_event->hlist_entry, list);

- /*
- * Ensure every events in profiling have finished before
- * releasing the buffers
- */
- synchronize_sched();
+ return 0;
+}

- free_percpu(buf);
- free_percpu(nmi_buf);
- }
+void perf_trace_disable(struct perf_event *p_event)
+{
+ hlist_del_rcu(&p_event->hlist_entry);
}

-void perf_trace_disable(int event_id)
+void perf_trace_destroy(struct perf_event *p_event)
{
- struct ftrace_event_call *event;
+ struct ftrace_event_call *tp_event = p_event->tp_event;
+ int i;

- mutex_lock(&event_mutex);
- list_for_each_entry(event, &ftrace_events, list) {
- if (event->event.type == event_id) {
- perf_trace_event_disable(event);
- module_put(event->mod);
- break;
+ if (--tp_event->perf_refcount > 0)
+ return;
+
+ if (tp_event->class->reg)
+ tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER);
+ else
+ tracepoint_probe_unregister(tp_event->name,
+ tp_event->class->perf_probe,
+ tp_event);
+
+ free_percpu(tp_event->perf_events);
+ tp_event->perf_events = NULL;
+
+ if (!--total_ref_count) {
+ for (i = 0; i < 4; i++) {
+ free_percpu(perf_trace_buf[i]);
+ perf_trace_buf[i] = NULL;
}
}
- mutex_unlock(&event_mutex);
}

__kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
- int *rctxp, unsigned long *irq_flags)
+ struct pt_regs *regs, int *rctxp)
{
struct trace_entry *entry;
- char *trace_buf, *raw_data;
- int pc, cpu;
+ char *raw_data;
+ int pc;

BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));

pc = preempt_count();

- /* Protect the per cpu buffer, begin the rcu read side */
- local_irq_save(*irq_flags);
-
*rctxp = perf_swevent_get_recursion_context();
if (*rctxp < 0)
- goto err_recursion;
-
- cpu = smp_processor_id();
-
- if (in_nmi())
- trace_buf = rcu_dereference_sched(perf_trace_buf_nmi);
- else
- trace_buf = rcu_dereference_sched(perf_trace_buf);
-
- if (!trace_buf)
- goto err;
+ return NULL;

- raw_data = per_cpu_ptr(trace_buf, cpu);
+ raw_data = per_cpu_ptr(perf_trace_buf[*rctxp], smp_processor_id());

/* zero the dead bytes from align to not leak stack to user */
memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));

entry = (struct trace_entry *)raw_data;
- tracing_generic_entry_update(entry, *irq_flags, pc);
+ tracing_generic_entry_update(entry, regs->flags, pc);
entry->type = type;

return raw_data;
-err:
- perf_swevent_put_recursion_context(*rctxp);
-err_recursion:
- local_irq_restore(*irq_flags);
- return NULL;
}
EXPORT_SYMBOL_GPL(perf_trace_buf_prepare);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9a082bb..faf7cef 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1338,9 +1338,9 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
struct ftrace_event_call *call = &tp->call;
struct kprobe_trace_entry_head *entry;
+ struct hlist_head *head;
u8 *data;
int size, __size, i;
- unsigned long irq_flags;
int rctx;

__size = sizeof(*entry) + tp->size;
@@ -1350,8 +1350,7 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
"profile buffer not large enough"))
return;

- entry = perf_trace_buf_prepare(size, call->event.type,
- &rctx, &irq_flags);
+ entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
if (!entry)
return;

@@ -1360,7 +1359,8 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
for (i = 0; i < tp->nr_args; i++)
call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);

- perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs);
+ head = per_cpu_ptr(call->perf_events, smp_processor_id());
+ perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
}

/* Kretprobe profile handler */
@@ -1370,9 +1370,9 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
struct ftrace_event_call *call = &tp->call;
struct kretprobe_trace_entry_head *entry;
+ struct hlist_head *head;
u8 *data;
int size, __size, i;
- unsigned long irq_flags;
int rctx;

__size = sizeof(*entry) + tp->size;
@@ -1382,8 +1382,7 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
"profile buffer not large enough"))
return;

- entry = perf_trace_buf_prepare(size, call->event.type,
- &rctx, &irq_flags);
+ entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
if (!entry)
return;

@@ -1393,8 +1392,8 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
for (i = 0; i < tp->nr_args; i++)
call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);

- perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1,
- irq_flags, regs);
+ head = per_cpu_ptr(call->perf_events, smp_processor_id());
+ perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
}

static int probe_perf_enable(struct ftrace_event_call *call)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 9d35830..d2c859c 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -488,7 +488,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
{
struct syscall_metadata *sys_data;
struct syscall_trace_enter *rec;
- unsigned long flags;
+ struct hlist_head *head;
int syscall_nr;
int rctx;
int size;
@@ -511,15 +511,16 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
return;

rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
- sys_data->enter_event->event.type,
- &rctx, &flags);
+ sys_data->enter_event->event.type, regs, &rctx);
if (!rec)
return;

rec->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args,
(unsigned long *)&rec->args);
- perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs);
+
+ head = per_cpu_ptr(sys_data->enter_event->perf_events, smp_processor_id());
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
}

int perf_sysenter_enable(struct ftrace_event_call *call)
@@ -561,7 +562,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
{
struct syscall_metadata *sys_data;
struct syscall_trace_exit *rec;
- unsigned long flags;
+ struct hlist_head *head;
int syscall_nr;
int rctx;
int size;
@@ -587,15 +588,15 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
return;

rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
- sys_data->exit_event->event.type,
- &rctx, &flags);
+ sys_data->exit_event->event.type, regs, &rctx);
if (!rec)
return;

rec->nr = syscall_nr;
rec->ret = syscall_get_return_value(current, regs);

- perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs);
+ head = per_cpu_ptr(sys_data->exit_event->perf_events, smp_processor_id());
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
}

int perf_sysexit_enable(struct ftrace_event_call *call)


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