[RFC] btf: Some structs are doubled because of struct ring_buffer

[RFC] btf: Some structs are doubled because of struct ring_buffer

[Jiri Olsa]

hi,
the current BTF vmlinux file have some of the structs doubled:

  $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep task_struct
  [150] STRUCT 'task_struct' size=11008 vlen=205
  [12262] STRUCT 'task_struct' size=11008 vlen=205

  $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "STRUCT 'perf_event'"
  [1666] STRUCT 'perf_event' size=1160 vlen=70
  [12301] STRUCT 'perf_event' size=1160 vlen=70

The reason seems to be that we have two distinct 'struct ring_buffer'
objects used in kernel: one in perf subsystem and one in kernel trace
subsystem.

When we compile kernel/trace/ring_buffer.c we have 'struct task_struct',
which references 'struct ring_buffer', which is at that compile time
defined in kernel/trace/ring_buffer.c.

While when we compile kernel/events/core.c we have 'struct task_struct',
which references ring buffer, which is at that compile time defined
in kernel/events/internal.h.

So we end up with 2 different 'struct task_struct' objects, and few
other objects which are on the way to the 'struct ring_buffer' field,
like:

	[1666] STRUCT 'perf_event' size=1160 vlen=70
		...
		'rb' type_id=2289 bits_offset=5632
		...

		[2289] PTR '(anon)' type_id=10872

			-> trace ring buffer

			[10872] STRUCT 'ring_buffer' size=184 vlen=12
				'flags' type_id=10 bits_offset=0
				'cpus' type_id=22 bits_offset=32
				'record_disabled' type_id=81 bits_offset=64
				...

	[12301] STRUCT 'perf_event' size=1160 vlen=70
		...
		'rb' type_id=13148 bits_offset=5632
		...

		[13148] PTR '(anon)' type_id=13147

			-> perf ring buffer

			[13147] STRUCT 'ring_buffer' size=240 vlen=33
				'refcount' type_id=795 bits_offset=0
				'callback_head' type_id=90 bits_offset=64
				'nr_pages' type_id=22 bits_offset=192
				'overwrite' type_id=22 bits_offset=224
				'paused' type_id=22 bits_offset=256
				...

I don't think dedup algorithm can handle this and I'm not sure if there's
some way in pahole to detect/prevent this.

I only found that if I rename the ring_buffer objects to have distinct
names, it will help:

  $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep task_struct
  [150] STRUCT 'task_struct' size=11008 vlen=205

  $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "STRUCT 'perf_event'"
  [1665] STRUCT 'perf_event' size=1160 vlen=70

also the BTF data get smaller ;-) before:

  $ ll /sys/kernel/btf/vmlinux
  -r--r--r--. 1 root root 2067432 Dec 13 22:56 /sys/kernel/btf/vmlinux

after:
  $ ll /sys/kernel/btf/vmlinux
  -r--r--r--. 1 root root 1984345 Dec 13 23:02 /sys/kernel/btf/vmlinux


Peter, Steven,
if above is correct and there's no other better solution, would it be possible
to straighten up the namespace and user some distinct names for perf and ftrace
ring buffers?

thoughts?
jirka

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Fri, 13 Dec 2019 16:35:53 +0100
Jiri Olsa <jolsa@redhat.com> wrote:

> I don't think dedup algorithm can handle this and I'm not sure if there's
> some way in pahole to detect/prevent this.
> 
> I only found that if I rename the ring_buffer objects to have distinct
> names, it will help:
> 
>   $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep task_struct
>   [150] STRUCT 'task_struct' size=11008 vlen=205
> 
>   $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "STRUCT 'perf_event'"
>   [1665] STRUCT 'perf_event' size=1160 vlen=70
> 
> also the BTF data get smaller ;-) before:
> 
>   $ ll /sys/kernel/btf/vmlinux
>   -r--r--r--. 1 root root 2067432 Dec 13 22:56 /sys/kernel/btf/vmlinux
> 
> after:
>   $ ll /sys/kernel/btf/vmlinux
>   -r--r--r--. 1 root root 1984345 Dec 13 23:02 /sys/kernel/btf/vmlinux
> 
> 
> Peter, Steven,
> if above is correct and there's no other better solution, would it be possible
> to straighten up the namespace and user some distinct names for perf and ftrace
> ring buffers?

Now, the ring buffer that ftrace uses is not specific for ftrace or
even tracing for that matter. It is a stand alone ring buffer (oprofile
uses it), and can be used by anyone else.

As the perf ring buffer is very coupled with perf (or perf events), and
unless something changed, I was never able to pull the perf ring
buffer out as a stand alone ring buffer.

As the ring buffer in the tracing directory is more generic, and not to
mention around longer, if one is to change the name, I would suggest it
be the perf ring buffer.

-- Steve

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Alexei Starovoitov]

On Fri, Dec 13, 2019 at 11:25:00AM -0500, Steven Rostedt wrote:
> On Fri, 13 Dec 2019 16:35:53 +0100
> Jiri Olsa <jolsa@redhat.com> wrote:
> 
> > I don't think dedup algorithm can handle this and I'm not sure if there's
> > some way in pahole to detect/prevent this.
> > 
> > I only found that if I rename the ring_buffer objects to have distinct
> > names, it will help:
> > 
> >   $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep task_struct
> >   [150] STRUCT 'task_struct' size=11008 vlen=205
> > 
> >   $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "STRUCT 'perf_event'"
> >   [1665] STRUCT 'perf_event' size=1160 vlen=70
> > 
> > also the BTF data get smaller ;-) before:
> > 
> >   $ ll /sys/kernel/btf/vmlinux
> >   -r--r--r--. 1 root root 2067432 Dec 13 22:56 /sys/kernel/btf/vmlinux
> > 
> > after:
> >   $ ll /sys/kernel/btf/vmlinux
> >   -r--r--r--. 1 root root 1984345 Dec 13 23:02 /sys/kernel/btf/vmlinux
> > 
> > 
> > Peter, Steven,
> > if above is correct and there's no other better solution, would it be possible
> > to straighten up the namespace and user some distinct names for perf and ftrace
> > ring buffers?
> 
> Now, the ring buffer that ftrace uses is not specific for ftrace or
> even tracing for that matter. It is a stand alone ring buffer (oprofile
> uses it), and can be used by anyone else.
> 
> As the perf ring buffer is very coupled with perf (or perf events), and
> unless something changed, I was never able to pull the perf ring
> buffer out as a stand alone ring buffer.
> 
> As the ring buffer in the tracing directory is more generic, and not to
> mention around longer, if one is to change the name, I would suggest it
> be the perf ring buffer.

Thanks Jiri to bring it up.
Technically the kernel is written in valid C, but it's imo the case where C
standard isn't doing that great.

To rephrase what Jiri said...
If include/linux/perf_event.h instead of saying 'struct ring_buffer;'
would have done #include <kernel/events/internal.h>
the kernel/trace/ring_buffer.c would have had build error.
Even now sizeof(*perf_event->rb) would return different values depending
whether it's used in kernel/trace/ring_buffer.c or anywhere in kernel/events/.
dwarf/btf and gcc cannot deal with it nicely. It's a valid C.

'gdb vmlinux' for sizeof(struct ring_buffer) will pick perf ring buffer.
It had two choices. Both valid. I don't know why gdb picked this one.
So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
good. I think renaming ftrace one would be better, since gdb picked perf one
for whatever reason.

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Fri, 13 Dec 2019 08:51:57 -0800
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:

> It had two choices. Both valid. I don't know why gdb picked this one.
> So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
> good. I think renaming ftrace one would be better, since gdb picked perf one
> for whatever reason.

Because of the sort algorithm. But from a technical perspective, the
ring buffer that ftrace uses is generic, where the perf ring buffer can
only be used for perf. Call it "event_ring_buffer" or whatever, but
it's not generic and should not have a generic name.

-- Steve

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Alexei Starovoitov]

On Fri, Dec 13, 2019 at 12:11:18PM -0500, Steven Rostedt wrote:
> On Fri, 13 Dec 2019 08:51:57 -0800
> Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> 
> > It had two choices. Both valid. I don't know why gdb picked this one.
> > So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
> > good. I think renaming ftrace one would be better, since gdb picked perf one
> > for whatever reason.
> 
> Because of the sort algorithm. But from a technical perspective, the
> ring buffer that ftrace uses is generic, where the perf ring buffer can
> only be used for perf. Call it "event_ring_buffer" or whatever, but
> it's not generic and should not have a generic name.

I don't mind whichever way. Just saying it would be good to rename :)

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Jiri Olsa]

On Fri, Dec 13, 2019 at 09:30:18AM -0800, Alexei Starovoitov wrote:
> On Fri, Dec 13, 2019 at 12:11:18PM -0500, Steven Rostedt wrote:
> > On Fri, 13 Dec 2019 08:51:57 -0800
> > Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> > 
> > > It had two choices. Both valid. I don't know why gdb picked this one.
> > > So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
> > > good. I think renaming ftrace one would be better, since gdb picked perf one
> > > for whatever reason.
> > 
> > Because of the sort algorithm. But from a technical perspective, the
> > ring buffer that ftrace uses is generic, where the perf ring buffer can
> > only be used for perf. Call it "event_ring_buffer" or whatever, but
> > it's not generic and should not have a generic name.
> 
> I don't mind whichever way. Just saying it would be good to rename :)
> 

Peter,
any chance we could use the 'struct perf_buffer' for perf?

thanks,
jirka

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Peter Zijlstra]

On Fri, Dec 13, 2019 at 12:11:18PM -0500, Steven Rostedt wrote:
> On Fri, 13 Dec 2019 08:51:57 -0800
> Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> 
> > It had two choices. Both valid. I don't know why gdb picked this one.
> > So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
> > good. I think renaming ftrace one would be better, since gdb picked perf one
> > for whatever reason.
> 
> Because of the sort algorithm. But from a technical perspective, the
> ring buffer that ftrace uses is generic, where the perf ring buffer can
> only be used for perf. Call it "event_ring_buffer" or whatever, but
> it's not generic and should not have a generic name.

Your ring buffer was so generic that I gave up trying to use it after
trying for days :-( (the fundamental problem was that it was impossible
to have a single cpu buffer; afaik that is still true today)

Nor is the perf buffer fundamentally specific to perf, but there not
being another user means there has been very little effort to remove
perf specific things from it.

There are major design differences between them, which is
unquestionably, but I don't think it is fair to say one is more or less
generic.

How about we rename both? I'm a bit adverse to long names, so how about
we rename the perf one to perf_buffer and the trace one to trace_buffer?

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Fri, 13 Dec 2019 19:02:23 +0100
Peter Zijlstra <peterz@infradead.org> wrote:

> On Fri, Dec 13, 2019 at 12:11:18PM -0500, Steven Rostedt wrote:
> > On Fri, 13 Dec 2019 08:51:57 -0800
> > Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> >   
> > > It had two choices. Both valid. I don't know why gdb picked this one.
> > > So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
> > > good. I think renaming ftrace one would be better, since gdb picked perf one
> > > for whatever reason.  
> > 
> > Because of the sort algorithm. But from a technical perspective, the
> > ring buffer that ftrace uses is generic, where the perf ring buffer can
> > only be used for perf. Call it "event_ring_buffer" or whatever, but
> > it's not generic and should not have a generic name.  
> 
> Your ring buffer was so generic that I gave up trying to use it after
> trying for days :-( (the fundamental problem was that it was impossible
> to have a single cpu buffer; afaik that is still true today)

Yeah, but that could have been fixed, and the only reason it's not
today, is because it requires more overhead to do so.

IIRC, the main reason that you didn't use it then, is because it wasn't
fully lockless at the time (it is today), and you couldn't use it from
NMI context.

> 
> Nor is the perf buffer fundamentally specific to perf, but there not
> being another user means there has been very little effort to remove
> perf specific things from it.

I took a look at doing so, and it was not a trivial task.

> 
> There are major design differences between them, which is
> unquestionably, but I don't think it is fair to say one is more or less
> generic.
> 
> How about we rename both? I'm a bit adverse to long names, so how about
> we rename the perf one to perf_buffer and the trace one to trace_buffer?

I'm fine with this idea! Now what do we call the ring buffer that
tracing uses, as it is not specific for tracing, it was optimized for
splicing. But sure, I can rename it to trace_buffer. I just finished
renaming perf's...

Thinking about this, perhaps we should remove the word "ring" from
both. That is:

  perf_buffer and trace_buffer ?

Anyway, here's the perf update, I can go ahead and rewrite the tracing
one too, and perhaps one day we can make a truly generic ring buffer!

-- Steve

From b457e9fe8366eef0ba00937e2a9a21899ca06e06 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Fri, 13 Dec 2019 13:21:30 -0500
Subject: [PATCH] perf: Make struct ring_buffer less ambiguous

eBPF requires needing to know the size of the perf ring buffer structure.
But it unfortunately has the same name as the generic ring buffer used by
tracing and oprofile. To make it less ambiguous, rename the perf ring buffer
structure to "perf_ring_buffer".

Now the reason to rename the ring buffer in perf and not the one used by
tracing and oprofile, is for the following reasons:

 1) The perf ring buffer is very coupled to perf.
    The ring buffer assumes that it is used for perf, and perf alone.
    It requires to be read by perf mmapping, and reqires the perf interface
     to read it.

    The ring buffer used by tracing is stand a lone, and has no references
    to tracing. This is why oprofile was able to use it as well.

 2) The perf ring buffer is quite contained.
    It is only used within the kernel/events directory.
    Only four files reference it, and only three require to know its
     contant (include/linux/perf_event.h just declares the reference)

 3) The perf ring buffer came after the generic ring buffer.
     When this ring buffer was added, it appeared that it was only going
     to be local as it used the same name as one that already existed.

The main reason to rename the perf ring buffer is because of #1 above.
It is not a generic ring buffer at all, and other parts of the ring
buffer code has "perf_" as the prefix, it only makes sense to give the
ring buffer the "perf_" prefix as well.

Link: https://lore.kernel.org/r/20191213153553.GE20583@krava
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/perf_event.h  |  6 ++---
 kernel/events/core.c        | 42 ++++++++++++++---------------
 kernel/events/internal.h    | 34 +++++++++++------------
 kernel/events/ring_buffer.c | 54 ++++++++++++++++++-------------------
 4 files changed, 68 insertions(+), 68 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 6d4c22aee384..b9adf826c393 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -582,7 +582,7 @@ struct swevent_hlist {
 #define PERF_ATTACH_ITRACE	0x10
 
 struct perf_cgroup;
-struct ring_buffer;
+struct perf_ring_buffer;
 
 struct pmu_event_list {
 	raw_spinlock_t		lock;
@@ -694,7 +694,7 @@ struct perf_event {
 	struct mutex			mmap_mutex;
 	atomic_t			mmap_count;
 
-	struct ring_buffer		*rb;
+	struct perf_ring_buffer		*rb;
 	struct list_head		rb_entry;
 	unsigned long			rcu_batches;
 	int				rcu_pending;
@@ -854,7 +854,7 @@ struct perf_cpu_context {
 
 struct perf_output_handle {
 	struct perf_event		*event;
-	struct ring_buffer		*rb;
+	struct perf_ring_buffer		*rb;
 	unsigned long			wakeup;
 	unsigned long			size;
 	u64				aux_flags;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4ff86d57f9e5..95308f7b62da 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4373,7 +4373,7 @@ static void free_event_rcu(struct rcu_head *head)
 }
 
 static void ring_buffer_attach(struct perf_event *event,
-			       struct ring_buffer *rb);
+			       struct perf_ring_buffer *rb);
 
 static void detach_sb_event(struct perf_event *event)
 {
@@ -5054,7 +5054,7 @@ perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 static __poll_t perf_poll(struct file *file, poll_table *wait)
 {
 	struct perf_event *event = file->private_data;
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	__poll_t events = EPOLLHUP;
 
 	poll_wait(file, &event->waitq, wait);
@@ -5296,7 +5296,7 @@ static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned lon
 		return perf_event_set_bpf_prog(event, arg);
 
 	case PERF_EVENT_IOC_PAUSE_OUTPUT: {
-		struct ring_buffer *rb;
+		struct perf_ring_buffer *rb;
 
 		rcu_read_lock();
 		rb = rcu_dereference(event->rb);
@@ -5432,7 +5432,7 @@ static void calc_timer_values(struct perf_event *event,
 static void perf_event_init_userpage(struct perf_event *event)
 {
 	struct perf_event_mmap_page *userpg;
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5464,7 +5464,7 @@ void __weak arch_perf_update_userpage(
 void perf_event_update_userpage(struct perf_event *event)
 {
 	struct perf_event_mmap_page *userpg;
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	u64 enabled, running, now;
 
 	rcu_read_lock();
@@ -5515,7 +5515,7 @@ EXPORT_SYMBOL_GPL(perf_event_update_userpage);
 static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
 {
 	struct perf_event *event = vmf->vma->vm_file->private_data;
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	vm_fault_t ret = VM_FAULT_SIGBUS;
 
 	if (vmf->flags & FAULT_FLAG_MKWRITE) {
@@ -5548,9 +5548,9 @@ static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
 }
 
 static void ring_buffer_attach(struct perf_event *event,
-			       struct ring_buffer *rb)
+			       struct perf_ring_buffer *rb)
 {
-	struct ring_buffer *old_rb = NULL;
+	struct perf_ring_buffer *old_rb = NULL;
 	unsigned long flags;
 
 	if (event->rb) {
@@ -5608,7 +5608,7 @@ static void ring_buffer_attach(struct perf_event *event,
 
 static void ring_buffer_wakeup(struct perf_event *event)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5619,9 +5619,9 @@ static void ring_buffer_wakeup(struct perf_event *event)
 	rcu_read_unlock();
 }
 
-struct ring_buffer *ring_buffer_get(struct perf_event *event)
+struct perf_ring_buffer *ring_buffer_get(struct perf_event *event)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5634,7 +5634,7 @@ struct ring_buffer *ring_buffer_get(struct perf_event *event)
 	return rb;
 }
 
-void ring_buffer_put(struct ring_buffer *rb)
+void ring_buffer_put(struct perf_ring_buffer *rb)
 {
 	if (!refcount_dec_and_test(&rb->refcount))
 		return;
@@ -5672,7 +5672,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
 {
 	struct perf_event *event = vma->vm_file->private_data;
 
-	struct ring_buffer *rb = ring_buffer_get(event);
+	struct perf_ring_buffer *rb = ring_buffer_get(event);
 	struct user_struct *mmap_user = rb->mmap_user;
 	int mmap_locked = rb->mmap_locked;
 	unsigned long size = perf_data_size(rb);
@@ -5790,8 +5790,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
 	struct perf_event *event = file->private_data;
 	unsigned long user_locked, user_lock_limit;
 	struct user_struct *user = current_user();
+	struct perf_ring_buffer *rb = NULL;
 	unsigned long locked, lock_limit;
-	struct ring_buffer *rb = NULL;
 	unsigned long vma_size;
 	unsigned long nr_pages;
 	long user_extra = 0, extra = 0;
@@ -6266,7 +6266,7 @@ static unsigned long perf_prepare_sample_aux(struct perf_event *event,
 					  size_t size)
 {
 	struct perf_event *sampler = event->aux_event;
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 
 	data->aux_size = 0;
 
@@ -6299,7 +6299,7 @@ static unsigned long perf_prepare_sample_aux(struct perf_event *event,
 	return data->aux_size;
 }
 
-long perf_pmu_snapshot_aux(struct ring_buffer *rb,
+long perf_pmu_snapshot_aux(struct perf_ring_buffer *rb,
 			   struct perf_event *event,
 			   struct perf_output_handle *handle,
 			   unsigned long size)
@@ -6338,8 +6338,8 @@ static void perf_aux_sample_output(struct perf_event *event,
 				   struct perf_sample_data *data)
 {
 	struct perf_event *sampler = event->aux_event;
+	struct perf_ring_buffer *rb;
 	unsigned long pad;
-	struct ring_buffer *rb;
 	long size;
 
 	if (WARN_ON_ONCE(!sampler || !data->aux_size))
@@ -6707,7 +6707,7 @@ void perf_output_sample(struct perf_output_handle *handle,
 		int wakeup_events = event->attr.wakeup_events;
 
 		if (wakeup_events) {
-			struct ring_buffer *rb = handle->rb;
+			struct perf_ring_buffer *rb = handle->rb;
 			int events = local_inc_return(&rb->events);
 
 			if (events >= wakeup_events) {
@@ -7150,7 +7150,7 @@ void perf_event_exec(void)
 }
 
 struct remote_output {
-	struct ring_buffer	*rb;
+	struct perf_ring_buffer	*rb;
 	int			err;
 };
 
@@ -7158,7 +7158,7 @@ static void __perf_event_output_stop(struct perf_event *event, void *data)
 {
 	struct perf_event *parent = event->parent;
 	struct remote_output *ro = data;
-	struct ring_buffer *rb = ro->rb;
+	struct perf_ring_buffer *rb = ro->rb;
 	struct stop_event_data sd = {
 		.event	= event,
 	};
@@ -10998,7 +10998,7 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
 static int
 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
 {
-	struct ring_buffer *rb = NULL;
+	struct perf_ring_buffer *rb = NULL;
 	int ret = -EINVAL;
 
 	if (!output_event)
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 747d67f130cb..820edf227747 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -10,7 +10,7 @@
 
 #define RING_BUFFER_WRITABLE		0x01
 
-struct ring_buffer {
+struct perf_ring_buffer {
 	refcount_t			refcount;
 	struct rcu_head			rcu_head;
 #ifdef CONFIG_PERF_USE_VMALLOC
@@ -58,17 +58,17 @@ struct ring_buffer {
 	void				*data_pages[0];
 };
 
-extern void rb_free(struct ring_buffer *rb);
+extern void rb_free(struct perf_ring_buffer *rb);
 
 static inline void rb_free_rcu(struct rcu_head *rcu_head)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 
-	rb = container_of(rcu_head, struct ring_buffer, rcu_head);
+	rb = container_of(rcu_head, struct perf_ring_buffer, rcu_head);
 	rb_free(rb);
 }
 
-static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
+static inline void rb_toggle_paused(struct perf_ring_buffer *rb, bool pause)
 {
 	if (!pause && rb->nr_pages)
 		rb->paused = 0;
@@ -76,16 +76,16 @@ static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
 		rb->paused = 1;
 }
 
-extern struct ring_buffer *
+extern struct perf_ring_buffer *
 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
 extern void perf_event_wakeup(struct perf_event *event);
-extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
+extern int rb_alloc_aux(struct perf_ring_buffer *rb, struct perf_event *event,
 			pgoff_t pgoff, int nr_pages, long watermark, int flags);
-extern void rb_free_aux(struct ring_buffer *rb);
-extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
-extern void ring_buffer_put(struct ring_buffer *rb);
+extern void rb_free_aux(struct perf_ring_buffer *rb);
+extern struct perf_ring_buffer *ring_buffer_get(struct perf_event *event);
+extern void ring_buffer_put(struct perf_ring_buffer *rb);
 
-static inline bool rb_has_aux(struct ring_buffer *rb)
+static inline bool rb_has_aux(struct perf_ring_buffer *rb)
 {
 	return !!rb->aux_nr_pages;
 }
@@ -94,7 +94,7 @@ void perf_event_aux_event(struct perf_event *event, unsigned long head,
 			  unsigned long size, u64 flags);
 
 extern struct page *
-perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
+perf_mmap_to_page(struct perf_ring_buffer *rb, unsigned long pgoff);
 
 #ifdef CONFIG_PERF_USE_VMALLOC
 /*
@@ -103,25 +103,25 @@ perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  * Required for architectures that have d-cache aliasing issues.
  */
 
-static inline int page_order(struct ring_buffer *rb)
+static inline int page_order(struct perf_ring_buffer *rb)
 {
 	return rb->page_order;
 }
 
 #else
 
-static inline int page_order(struct ring_buffer *rb)
+static inline int page_order(struct perf_ring_buffer *rb)
 {
 	return 0;
 }
 #endif
 
-static inline unsigned long perf_data_size(struct ring_buffer *rb)
+static inline unsigned long perf_data_size(struct perf_ring_buffer *rb)
 {
 	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 }
 
-static inline unsigned long perf_aux_size(struct ring_buffer *rb)
+static inline unsigned long perf_aux_size(struct perf_ring_buffer *rb)
 {
 	return rb->aux_nr_pages << PAGE_SHIFT;
 }
@@ -141,7 +141,7 @@ static inline unsigned long perf_aux_size(struct ring_buffer *rb)
 			buf += written;					\
 		handle->size -= written;				\
 		if (!handle->size) {					\
-			struct ring_buffer *rb = handle->rb;		\
+			struct perf_ring_buffer *rb = handle->rb;	\
 									\
 			handle->page++;					\
 			handle->page &= rb->nr_pages - 1;		\
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 7ffd5c763f93..70230b45e6c5 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -35,7 +35,7 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
  */
 static void perf_output_get_handle(struct perf_output_handle *handle)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_ring_buffer *rb = handle->rb;
 
 	preempt_disable();
 
@@ -49,7 +49,7 @@ static void perf_output_get_handle(struct perf_output_handle *handle)
 
 static void perf_output_put_handle(struct perf_output_handle *handle)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_ring_buffer *rb = handle->rb;
 	unsigned long head;
 	unsigned int nest;
 
@@ -150,7 +150,7 @@ __perf_output_begin(struct perf_output_handle *handle,
 		    struct perf_event *event, unsigned int size,
 		    bool backward)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	unsigned long tail, offset, head;
 	int have_lost, page_shift;
 	struct {
@@ -301,7 +301,7 @@ void perf_output_end(struct perf_output_handle *handle)
 }
 
 static void
-ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
+ring_buffer_init(struct perf_ring_buffer *rb, long watermark, int flags)
 {
 	long max_size = perf_data_size(rb);
 
@@ -361,7 +361,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 {
 	struct perf_event *output_event = event;
 	unsigned long aux_head, aux_tail;
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	unsigned int nest;
 
 	if (output_event->parent)
@@ -449,7 +449,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 }
 EXPORT_SYMBOL_GPL(perf_aux_output_begin);
 
-static __always_inline bool rb_need_aux_wakeup(struct ring_buffer *rb)
+static __always_inline bool rb_need_aux_wakeup(struct perf_ring_buffer *rb)
 {
 	if (rb->aux_overwrite)
 		return false;
@@ -475,7 +475,7 @@ static __always_inline bool rb_need_aux_wakeup(struct ring_buffer *rb)
 void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
 {
 	bool wakeup = !!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED);
-	struct ring_buffer *rb = handle->rb;
+	struct perf_ring_buffer *rb = handle->rb;
 	unsigned long aux_head;
 
 	/* in overwrite mode, driver provides aux_head via handle */
@@ -532,7 +532,7 @@ EXPORT_SYMBOL_GPL(perf_aux_output_end);
  */
 int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_ring_buffer *rb = handle->rb;
 
 	if (size > handle->size)
 		return -ENOSPC;
@@ -569,8 +569,8 @@ long perf_output_copy_aux(struct perf_output_handle *aux_handle,
 			  struct perf_output_handle *handle,
 			  unsigned long from, unsigned long to)
 {
+	struct perf_ring_buffer *rb = aux_handle->rb;
 	unsigned long tocopy, remainder, len = 0;
-	struct ring_buffer *rb = aux_handle->rb;
 	void *addr;
 
 	from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
@@ -626,7 +626,7 @@ static struct page *rb_alloc_aux_page(int node, int order)
 	return page;
 }
 
-static void rb_free_aux_page(struct ring_buffer *rb, int idx)
+static void rb_free_aux_page(struct perf_ring_buffer *rb, int idx)
 {
 	struct page *page = virt_to_page(rb->aux_pages[idx]);
 
@@ -635,7 +635,7 @@ static void rb_free_aux_page(struct ring_buffer *rb, int idx)
 	__free_page(page);
 }
 
-static void __rb_free_aux(struct ring_buffer *rb)
+static void __rb_free_aux(struct perf_ring_buffer *rb)
 {
 	int pg;
 
@@ -662,7 +662,7 @@ static void __rb_free_aux(struct ring_buffer *rb)
 	}
 }
 
-int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
+int rb_alloc_aux(struct perf_ring_buffer *rb, struct perf_event *event,
 		 pgoff_t pgoff, int nr_pages, long watermark, int flags)
 {
 	bool overwrite = !(flags & RING_BUFFER_WRITABLE);
@@ -753,7 +753,7 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
 	return ret;
 }
 
-void rb_free_aux(struct ring_buffer *rb)
+void rb_free_aux(struct perf_ring_buffer *rb)
 {
 	if (refcount_dec_and_test(&rb->aux_refcount))
 		__rb_free_aux(rb);
@@ -766,7 +766,7 @@ void rb_free_aux(struct ring_buffer *rb)
  */
 
 static struct page *
-__perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+__perf_mmap_to_page(struct perf_ring_buffer *rb, unsigned long pgoff)
 {
 	if (pgoff > rb->nr_pages)
 		return NULL;
@@ -798,13 +798,13 @@ static void perf_mmap_free_page(void *addr)
 	__free_page(page);
 }
 
-struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+struct perf_ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	unsigned long size;
 	int i;
 
-	size = sizeof(struct ring_buffer);
+	size = sizeof(struct perf_ring_buffer);
 	size += nr_pages * sizeof(void *);
 
 	if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
@@ -843,7 +843,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 	return NULL;
 }
 
-void rb_free(struct ring_buffer *rb)
+void rb_free(struct perf_ring_buffer *rb)
 {
 	int i;
 
@@ -854,13 +854,13 @@ void rb_free(struct ring_buffer *rb)
 }
 
 #else
-static int data_page_nr(struct ring_buffer *rb)
+static int data_page_nr(struct perf_ring_buffer *rb)
 {
 	return rb->nr_pages << page_order(rb);
 }
 
 static struct page *
-__perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+__perf_mmap_to_page(struct perf_ring_buffer *rb, unsigned long pgoff)
 {
 	/* The '>' counts in the user page. */
 	if (pgoff > data_page_nr(rb))
@@ -878,11 +878,11 @@ static void perf_mmap_unmark_page(void *addr)
 
 static void rb_free_work(struct work_struct *work)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	void *base;
 	int i, nr;
 
-	rb = container_of(work, struct ring_buffer, work);
+	rb = container_of(work, struct perf_ring_buffer, work);
 	nr = data_page_nr(rb);
 
 	base = rb->user_page;
@@ -894,18 +894,18 @@ static void rb_free_work(struct work_struct *work)
 	kfree(rb);
 }
 
-void rb_free(struct ring_buffer *rb)
+void rb_free(struct perf_ring_buffer *rb)
 {
 	schedule_work(&rb->work);
 }
 
-struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+struct perf_ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 {
-	struct ring_buffer *rb;
+	struct perf_ring_buffer *rb;
 	unsigned long size;
 	void *all_buf;
 
-	size = sizeof(struct ring_buffer);
+	size = sizeof(struct perf_ring_buffer);
 	size += sizeof(void *);
 
 	rb = kzalloc(size, GFP_KERNEL);
@@ -939,7 +939,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 #endif
 
 struct page *
-perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+perf_mmap_to_page(struct perf_ring_buffer *rb, unsigned long pgoff)
 {
 	if (rb->aux_nr_pages) {
 		/* above AUX space */
-- 
2.20.1

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Jiri Olsa]

On Fri, Dec 13, 2019 at 01:29:41PM -0500, Steven Rostedt wrote:
> On Fri, 13 Dec 2019 19:02:23 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > On Fri, Dec 13, 2019 at 12:11:18PM -0500, Steven Rostedt wrote:
> > > On Fri, 13 Dec 2019 08:51:57 -0800
> > > Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> > >   
> > > > It had two choices. Both valid. I don't know why gdb picked this one.
> > > > So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be
> > > > good. I think renaming ftrace one would be better, since gdb picked perf one
> > > > for whatever reason.  
> > > 
> > > Because of the sort algorithm. But from a technical perspective, the
> > > ring buffer that ftrace uses is generic, where the perf ring buffer can
> > > only be used for perf. Call it "event_ring_buffer" or whatever, but
> > > it's not generic and should not have a generic name.  
> > 
> > Your ring buffer was so generic that I gave up trying to use it after
> > trying for days :-( (the fundamental problem was that it was impossible
> > to have a single cpu buffer; afaik that is still true today)
> 
> Yeah, but that could have been fixed, and the only reason it's not
> today, is because it requires more overhead to do so.
> 
> IIRC, the main reason that you didn't use it then, is because it wasn't
> fully lockless at the time (it is today), and you couldn't use it from
> NMI context.
> 
> > 
> > Nor is the perf buffer fundamentally specific to perf, but there not
> > being another user means there has been very little effort to remove
> > perf specific things from it.
> 
> I took a look at doing so, and it was not a trivial task.
> 
> > 
> > There are major design differences between them, which is
> > unquestionably, but I don't think it is fair to say one is more or less
> > generic.
> > 
> > How about we rename both? I'm a bit adverse to long names, so how about
> > we rename the perf one to perf_buffer and the trace one to trace_buffer?
> 
> I'm fine with this idea! Now what do we call the ring buffer that
> tracing uses, as it is not specific for tracing, it was optimized for
> splicing. But sure, I can rename it to trace_buffer. I just finished
> renaming perf's...
> 
> Thinking about this, perhaps we should remove the word "ring" from
> both. That is:
> 
>   perf_buffer and trace_buffer ?

sounds good to me.. and too good to be true ;-)
please let me know if I should send the perf change

thanks,
jirka

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Fri, 13 Dec 2019 19:36:46 +0100
Jiri Olsa <jolsa@redhat.com> wrote:

> > Thinking about this, perhaps we should remove the word "ring" from
> > both. That is:
> > 
> >   perf_buffer and trace_buffer ?  
> 
> sounds good to me.. and too good to be true ;-)
> please let me know if I should send the perf change

Note, changing the other one is a lot more invasive. It's not as easy
as I thought. I forgot that even blktrace uses it. And a lot of the
trace event code is tied to the ring buffer code, as well as every
tracer.

-- Steve

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Peter Zijlstra]

On Fri, Dec 13, 2019 at 01:29:41PM -0500, Steven Rostedt wrote:
> On Fri, 13 Dec 2019 19:02:23 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:

> > Your ring buffer was so generic that I gave up trying to use it after
> > trying for days :-( (the fundamental problem was that it was impossible
> > to have a single cpu buffer; afaik that is still true today)
> 
> Yeah, but that could have been fixed, and the only reason it's not
> today, is because it requires more overhead to do so.
> 
> IIRC, the main reason that you didn't use it then, is because it wasn't
> fully lockless at the time (it is today), and you couldn't use it from
> NMI context.

What I remember is that I couldn't get a single cpu buffer, the whole
per-cpu stuff was mangled in at the wrong layer. But who knows, my
memory is faulty.


> > How about we rename both? I'm a bit adverse to long names, so how about
> > we rename the perf one to perf_buffer and the trace one to trace_buffer?
> 
> I'm fine with this idea! Now what do we call the ring buffer that
> tracing uses, as it is not specific for tracing, it was optimized for
> splicing. But sure, I can rename it to trace_buffer. I just finished
> renaming perf's...
> 
> Thinking about this, perhaps we should remove the word "ring" from
> both. That is:
> 
>   perf_buffer and trace_buffer ?

That's what I just proposed, right? So ACK on that ;-)

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Fri, 13 Dec 2019 19:46:21 +0100
Peter Zijlstra <peterz@infradead.org> wrote:

> >   perf_buffer and trace_buffer ?  
> 
> That's what I just proposed, right? So ACK on that ;-)

Anyway, here's v2, followed by the tracing one, which has the diffstat
of:

 drivers/oprofile/cpu_buffer.c        |   2 +-
 include/linux/ring_buffer.h          | 110 ++++++++++++------------
 include/linux/trace_events.h         |   4 +-
 include/trace/trace_events.h         |   2 +-
 kernel/trace/blktrace.c              |   4 +-
 kernel/trace/ring_buffer.c           | 124 +++++++++++++--------------
 kernel/trace/ring_buffer_benchmark.c |   2 +-
 kernel/trace/trace.c                 |  70 +++++++--------
 kernel/trace/trace.h                 |  22 ++---
 kernel/trace/trace_branch.c          |   2 +-
 kernel/trace/trace_events.c          |   2 +-
 kernel/trace/trace_events_hist.c     |   2 +-
 kernel/trace/trace_functions_graph.c |   4 +-
 kernel/trace/trace_hwlat.c           |   2 +-
 kernel/trace/trace_kprobe.c          |   4 +-
 kernel/trace/trace_mmiotrace.c       |   4 +-
 kernel/trace/trace_sched_wakeup.c    |   4 +-
 kernel/trace/trace_syscalls.c        |   4 +-
 kernel/trace/trace_uprobe.c          |   2 +-
 19 files changed, 185 insertions(+), 185 deletions(-)


-- Steve

From d15abd76c3d39741fd53e7e5846b07001f3cd895 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Fri, 13 Dec 2019 13:21:30 -0500
Subject: [PATCH] perf: Make struct ring_buffer less ambiguous

eBPF requires needing to know the size of the perf ring buffer structure.
But it unfortunately has the same name as the generic ring buffer used by
tracing and oprofile. To make it less ambiguous, rename the perf ring buffer
structure to "perf_buffer".

As other parts of the ring buffer code has "perf_" as the prefix, it only
makes sense to give the ring buffer the "perf_" prefix as well.

Link: https://lore.kernel.org/r/20191213153553.GE20583@krava
Acked-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/perf_event.h  |  6 ++---
 kernel/events/core.c        | 42 ++++++++++++++---------------
 kernel/events/internal.h    | 34 +++++++++++------------
 kernel/events/ring_buffer.c | 54 ++++++++++++++++++-------------------
 4 files changed, 68 insertions(+), 68 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 6d4c22aee384..cf65763af0cb 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -582,7 +582,7 @@ struct swevent_hlist {
 #define PERF_ATTACH_ITRACE	0x10
 
 struct perf_cgroup;
-struct ring_buffer;
+struct perf_buffer;
 
 struct pmu_event_list {
 	raw_spinlock_t		lock;
@@ -694,7 +694,7 @@ struct perf_event {
 	struct mutex			mmap_mutex;
 	atomic_t			mmap_count;
 
-	struct ring_buffer		*rb;
+	struct perf_buffer		*rb;
 	struct list_head		rb_entry;
 	unsigned long			rcu_batches;
 	int				rcu_pending;
@@ -854,7 +854,7 @@ struct perf_cpu_context {
 
 struct perf_output_handle {
 	struct perf_event		*event;
-	struct ring_buffer		*rb;
+	struct perf_buffer		*rb;
 	unsigned long			wakeup;
 	unsigned long			size;
 	u64				aux_flags;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4ff86d57f9e5..2871c4d2bd53 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4373,7 +4373,7 @@ static void free_event_rcu(struct rcu_head *head)
 }
 
 static void ring_buffer_attach(struct perf_event *event,
-			       struct ring_buffer *rb);
+			       struct perf_buffer *rb);
 
 static void detach_sb_event(struct perf_event *event)
 {
@@ -5054,7 +5054,7 @@ perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 static __poll_t perf_poll(struct file *file, poll_table *wait)
 {
 	struct perf_event *event = file->private_data;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	__poll_t events = EPOLLHUP;
 
 	poll_wait(file, &event->waitq, wait);
@@ -5296,7 +5296,7 @@ static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned lon
 		return perf_event_set_bpf_prog(event, arg);
 
 	case PERF_EVENT_IOC_PAUSE_OUTPUT: {
-		struct ring_buffer *rb;
+		struct perf_buffer *rb;
 
 		rcu_read_lock();
 		rb = rcu_dereference(event->rb);
@@ -5432,7 +5432,7 @@ static void calc_timer_values(struct perf_event *event,
 static void perf_event_init_userpage(struct perf_event *event)
 {
 	struct perf_event_mmap_page *userpg;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5464,7 +5464,7 @@ void __weak arch_perf_update_userpage(
 void perf_event_update_userpage(struct perf_event *event)
 {
 	struct perf_event_mmap_page *userpg;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	u64 enabled, running, now;
 
 	rcu_read_lock();
@@ -5515,7 +5515,7 @@ EXPORT_SYMBOL_GPL(perf_event_update_userpage);
 static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
 {
 	struct perf_event *event = vmf->vma->vm_file->private_data;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	vm_fault_t ret = VM_FAULT_SIGBUS;
 
 	if (vmf->flags & FAULT_FLAG_MKWRITE) {
@@ -5548,9 +5548,9 @@ static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
 }
 
 static void ring_buffer_attach(struct perf_event *event,
-			       struct ring_buffer *rb)
+			       struct perf_buffer *rb)
 {
-	struct ring_buffer *old_rb = NULL;
+	struct perf_buffer *old_rb = NULL;
 	unsigned long flags;
 
 	if (event->rb) {
@@ -5608,7 +5608,7 @@ static void ring_buffer_attach(struct perf_event *event,
 
 static void ring_buffer_wakeup(struct perf_event *event)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5619,9 +5619,9 @@ static void ring_buffer_wakeup(struct perf_event *event)
 	rcu_read_unlock();
 }
 
-struct ring_buffer *ring_buffer_get(struct perf_event *event)
+struct perf_buffer *ring_buffer_get(struct perf_event *event)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
 	rcu_read_lock();
 	rb = rcu_dereference(event->rb);
@@ -5634,7 +5634,7 @@ struct ring_buffer *ring_buffer_get(struct perf_event *event)
 	return rb;
 }
 
-void ring_buffer_put(struct ring_buffer *rb)
+void ring_buffer_put(struct perf_buffer *rb)
 {
 	if (!refcount_dec_and_test(&rb->refcount))
 		return;
@@ -5672,7 +5672,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
 {
 	struct perf_event *event = vma->vm_file->private_data;
 
-	struct ring_buffer *rb = ring_buffer_get(event);
+	struct perf_buffer *rb = ring_buffer_get(event);
 	struct user_struct *mmap_user = rb->mmap_user;
 	int mmap_locked = rb->mmap_locked;
 	unsigned long size = perf_data_size(rb);
@@ -5790,8 +5790,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
 	struct perf_event *event = file->private_data;
 	unsigned long user_locked, user_lock_limit;
 	struct user_struct *user = current_user();
+	struct perf_buffer *rb = NULL;
 	unsigned long locked, lock_limit;
-	struct ring_buffer *rb = NULL;
 	unsigned long vma_size;
 	unsigned long nr_pages;
 	long user_extra = 0, extra = 0;
@@ -6266,7 +6266,7 @@ static unsigned long perf_prepare_sample_aux(struct perf_event *event,
 					  size_t size)
 {
 	struct perf_event *sampler = event->aux_event;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
 	data->aux_size = 0;
 
@@ -6299,7 +6299,7 @@ static unsigned long perf_prepare_sample_aux(struct perf_event *event,
 	return data->aux_size;
 }
 
-long perf_pmu_snapshot_aux(struct ring_buffer *rb,
+long perf_pmu_snapshot_aux(struct perf_buffer *rb,
 			   struct perf_event *event,
 			   struct perf_output_handle *handle,
 			   unsigned long size)
@@ -6338,8 +6338,8 @@ static void perf_aux_sample_output(struct perf_event *event,
 				   struct perf_sample_data *data)
 {
 	struct perf_event *sampler = event->aux_event;
+	struct perf_buffer *rb;
 	unsigned long pad;
-	struct ring_buffer *rb;
 	long size;
 
 	if (WARN_ON_ONCE(!sampler || !data->aux_size))
@@ -6707,7 +6707,7 @@ void perf_output_sample(struct perf_output_handle *handle,
 		int wakeup_events = event->attr.wakeup_events;
 
 		if (wakeup_events) {
-			struct ring_buffer *rb = handle->rb;
+			struct perf_buffer *rb = handle->rb;
 			int events = local_inc_return(&rb->events);
 
 			if (events >= wakeup_events) {
@@ -7150,7 +7150,7 @@ void perf_event_exec(void)
 }
 
 struct remote_output {
-	struct ring_buffer	*rb;
+	struct perf_buffer	*rb;
 	int			err;
 };
 
@@ -7158,7 +7158,7 @@ static void __perf_event_output_stop(struct perf_event *event, void *data)
 {
 	struct perf_event *parent = event->parent;
 	struct remote_output *ro = data;
-	struct ring_buffer *rb = ro->rb;
+	struct perf_buffer *rb = ro->rb;
 	struct stop_event_data sd = {
 		.event	= event,
 	};
@@ -10998,7 +10998,7 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
 static int
 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
 {
-	struct ring_buffer *rb = NULL;
+	struct perf_buffer *rb = NULL;
 	int ret = -EINVAL;
 
 	if (!output_event)
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 747d67f130cb..f16f66b6b655 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -10,7 +10,7 @@
 
 #define RING_BUFFER_WRITABLE		0x01
 
-struct ring_buffer {
+struct perf_buffer {
 	refcount_t			refcount;
 	struct rcu_head			rcu_head;
 #ifdef CONFIG_PERF_USE_VMALLOC
@@ -58,17 +58,17 @@ struct ring_buffer {
 	void				*data_pages[0];
 };
 
-extern void rb_free(struct ring_buffer *rb);
+extern void rb_free(struct perf_buffer *rb);
 
 static inline void rb_free_rcu(struct rcu_head *rcu_head)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 
-	rb = container_of(rcu_head, struct ring_buffer, rcu_head);
+	rb = container_of(rcu_head, struct perf_buffer, rcu_head);
 	rb_free(rb);
 }
 
-static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
+static inline void rb_toggle_paused(struct perf_buffer *rb, bool pause)
 {
 	if (!pause && rb->nr_pages)
 		rb->paused = 0;
@@ -76,16 +76,16 @@ static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause)
 		rb->paused = 1;
 }
 
-extern struct ring_buffer *
+extern struct perf_buffer *
 rb_alloc(int nr_pages, long watermark, int cpu, int flags);
 extern void perf_event_wakeup(struct perf_event *event);
-extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
+extern int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
 			pgoff_t pgoff, int nr_pages, long watermark, int flags);
-extern void rb_free_aux(struct ring_buffer *rb);
-extern struct ring_buffer *ring_buffer_get(struct perf_event *event);
-extern void ring_buffer_put(struct ring_buffer *rb);
+extern void rb_free_aux(struct perf_buffer *rb);
+extern struct perf_buffer *ring_buffer_get(struct perf_event *event);
+extern void ring_buffer_put(struct perf_buffer *rb);
 
-static inline bool rb_has_aux(struct ring_buffer *rb)
+static inline bool rb_has_aux(struct perf_buffer *rb)
 {
 	return !!rb->aux_nr_pages;
 }
@@ -94,7 +94,7 @@ void perf_event_aux_event(struct perf_event *event, unsigned long head,
 			  unsigned long size, u64 flags);
 
 extern struct page *
-perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
+perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff);
 
 #ifdef CONFIG_PERF_USE_VMALLOC
 /*
@@ -103,25 +103,25 @@ perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
  * Required for architectures that have d-cache aliasing issues.
  */
 
-static inline int page_order(struct ring_buffer *rb)
+static inline int page_order(struct perf_buffer *rb)
 {
 	return rb->page_order;
 }
 
 #else
 
-static inline int page_order(struct ring_buffer *rb)
+static inline int page_order(struct perf_buffer *rb)
 {
 	return 0;
 }
 #endif
 
-static inline unsigned long perf_data_size(struct ring_buffer *rb)
+static inline unsigned long perf_data_size(struct perf_buffer *rb)
 {
 	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
 }
 
-static inline unsigned long perf_aux_size(struct ring_buffer *rb)
+static inline unsigned long perf_aux_size(struct perf_buffer *rb)
 {
 	return rb->aux_nr_pages << PAGE_SHIFT;
 }
@@ -141,7 +141,7 @@ static inline unsigned long perf_aux_size(struct ring_buffer *rb)
 			buf += written;					\
 		handle->size -= written;				\
 		if (!handle->size) {					\
-			struct ring_buffer *rb = handle->rb;		\
+			struct perf_buffer *rb = handle->rb;	\
 									\
 			handle->page++;					\
 			handle->page &= rb->nr_pages - 1;		\
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 7ffd5c763f93..192b8abc6330 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -35,7 +35,7 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
  */
 static void perf_output_get_handle(struct perf_output_handle *handle)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 
 	preempt_disable();
 
@@ -49,7 +49,7 @@ static void perf_output_get_handle(struct perf_output_handle *handle)
 
 static void perf_output_put_handle(struct perf_output_handle *handle)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 	unsigned long head;
 	unsigned int nest;
 
@@ -150,7 +150,7 @@ __perf_output_begin(struct perf_output_handle *handle,
 		    struct perf_event *event, unsigned int size,
 		    bool backward)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned long tail, offset, head;
 	int have_lost, page_shift;
 	struct {
@@ -301,7 +301,7 @@ void perf_output_end(struct perf_output_handle *handle)
 }
 
 static void
-ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
+ring_buffer_init(struct perf_buffer *rb, long watermark, int flags)
 {
 	long max_size = perf_data_size(rb);
 
@@ -361,7 +361,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 {
 	struct perf_event *output_event = event;
 	unsigned long aux_head, aux_tail;
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned int nest;
 
 	if (output_event->parent)
@@ -449,7 +449,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 }
 EXPORT_SYMBOL_GPL(perf_aux_output_begin);
 
-static __always_inline bool rb_need_aux_wakeup(struct ring_buffer *rb)
+static __always_inline bool rb_need_aux_wakeup(struct perf_buffer *rb)
 {
 	if (rb->aux_overwrite)
 		return false;
@@ -475,7 +475,7 @@ static __always_inline bool rb_need_aux_wakeup(struct ring_buffer *rb)
 void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
 {
 	bool wakeup = !!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED);
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 	unsigned long aux_head;
 
 	/* in overwrite mode, driver provides aux_head via handle */
@@ -532,7 +532,7 @@ EXPORT_SYMBOL_GPL(perf_aux_output_end);
  */
 int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size)
 {
-	struct ring_buffer *rb = handle->rb;
+	struct perf_buffer *rb = handle->rb;
 
 	if (size > handle->size)
 		return -ENOSPC;
@@ -569,8 +569,8 @@ long perf_output_copy_aux(struct perf_output_handle *aux_handle,
 			  struct perf_output_handle *handle,
 			  unsigned long from, unsigned long to)
 {
+	struct perf_buffer *rb = aux_handle->rb;
 	unsigned long tocopy, remainder, len = 0;
-	struct ring_buffer *rb = aux_handle->rb;
 	void *addr;
 
 	from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
@@ -626,7 +626,7 @@ static struct page *rb_alloc_aux_page(int node, int order)
 	return page;
 }
 
-static void rb_free_aux_page(struct ring_buffer *rb, int idx)
+static void rb_free_aux_page(struct perf_buffer *rb, int idx)
 {
 	struct page *page = virt_to_page(rb->aux_pages[idx]);
 
@@ -635,7 +635,7 @@ static void rb_free_aux_page(struct ring_buffer *rb, int idx)
 	__free_page(page);
 }
 
-static void __rb_free_aux(struct ring_buffer *rb)
+static void __rb_free_aux(struct perf_buffer *rb)
 {
 	int pg;
 
@@ -662,7 +662,7 @@ static void __rb_free_aux(struct ring_buffer *rb)
 	}
 }
 
-int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
+int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
 		 pgoff_t pgoff, int nr_pages, long watermark, int flags)
 {
 	bool overwrite = !(flags & RING_BUFFER_WRITABLE);
@@ -753,7 +753,7 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
 	return ret;
 }
 
-void rb_free_aux(struct ring_buffer *rb)
+void rb_free_aux(struct perf_buffer *rb)
 {
 	if (refcount_dec_and_test(&rb->aux_refcount))
 		__rb_free_aux(rb);
@@ -766,7 +766,7 @@ void rb_free_aux(struct ring_buffer *rb)
  */
 
 static struct page *
-__perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+__perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff)
 {
 	if (pgoff > rb->nr_pages)
 		return NULL;
@@ -798,13 +798,13 @@ static void perf_mmap_free_page(void *addr)
 	__free_page(page);
 }
 
-struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned long size;
 	int i;
 
-	size = sizeof(struct ring_buffer);
+	size = sizeof(struct perf_buffer);
 	size += nr_pages * sizeof(void *);
 
 	if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
@@ -843,7 +843,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 	return NULL;
 }
 
-void rb_free(struct ring_buffer *rb)
+void rb_free(struct perf_buffer *rb)
 {
 	int i;
 
@@ -854,13 +854,13 @@ void rb_free(struct ring_buffer *rb)
 }
 
 #else
-static int data_page_nr(struct ring_buffer *rb)
+static int data_page_nr(struct perf_buffer *rb)
 {
 	return rb->nr_pages << page_order(rb);
 }
 
 static struct page *
-__perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+__perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff)
 {
 	/* The '>' counts in the user page. */
 	if (pgoff > data_page_nr(rb))
@@ -878,11 +878,11 @@ static void perf_mmap_unmark_page(void *addr)
 
 static void rb_free_work(struct work_struct *work)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	void *base;
 	int i, nr;
 
-	rb = container_of(work, struct ring_buffer, work);
+	rb = container_of(work, struct perf_buffer, work);
 	nr = data_page_nr(rb);
 
 	base = rb->user_page;
@@ -894,18 +894,18 @@ static void rb_free_work(struct work_struct *work)
 	kfree(rb);
 }
 
-void rb_free(struct ring_buffer *rb)
+void rb_free(struct perf_buffer *rb)
 {
 	schedule_work(&rb->work);
 }
 
-struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 {
-	struct ring_buffer *rb;
+	struct perf_buffer *rb;
 	unsigned long size;
 	void *all_buf;
 
-	size = sizeof(struct ring_buffer);
+	size = sizeof(struct perf_buffer);
 	size += sizeof(void *);
 
 	rb = kzalloc(size, GFP_KERNEL);
@@ -939,7 +939,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 #endif
 
 struct page *
-perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff)
 {
 	if (rb->aux_nr_pages) {
 		/* above AUX space */
-- 
2.20.1

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Fri, 13 Dec 2019 14:03:49 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Fri, 13 Dec 2019 19:46:21 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > >   perf_buffer and trace_buffer ?    
> > 
> > That's what I just proposed, right? So ACK on that ;-)  
> 
> Anyway, here's v2, followed by the tracing one,

And here's the one for tracing. If you want to take the first patch (I
can send it again as a proper stand alone patch), then I'll take this
one.

-- Steve

From 81bc7202413e3194f035562054c6947984010711 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Fri, 13 Dec 2019 13:58:57 -0500
Subject: [PATCH] tracing: Make struct ring_buffer less ambiguous

As there's two struct ring_buffers in the kernel, it causes some confusion.
The other one being the perf ring buffer. It was agreed upon that as neither
of the ring buffers are generic enough to be used globally, they should be
renamed as:

   perf's ring_buffer -> perf_buffer
   ftrace's ring_buffer -> trace_buffer

This implements the changes to the ring buffer that ftrace uses.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 drivers/oprofile/cpu_buffer.c        |   2 +-
 include/linux/ring_buffer.h          | 110 ++++++++++++------------
 include/linux/trace_events.h         |   4 +-
 include/trace/trace_events.h         |   2 +-
 kernel/trace/blktrace.c              |   4 +-
 kernel/trace/ring_buffer.c           | 124 +++++++++++++--------------
 kernel/trace/ring_buffer_benchmark.c |   2 +-
 kernel/trace/trace.c                 |  70 +++++++--------
 kernel/trace/trace.h                 |  22 ++---
 kernel/trace/trace_branch.c          |   2 +-
 kernel/trace/trace_events.c          |   2 +-
 kernel/trace/trace_events_hist.c     |   2 +-
 kernel/trace/trace_functions_graph.c |   4 +-
 kernel/trace/trace_hwlat.c           |   2 +-
 kernel/trace/trace_kprobe.c          |   4 +-
 kernel/trace/trace_mmiotrace.c       |   4 +-
 kernel/trace/trace_sched_wakeup.c    |   4 +-
 kernel/trace/trace_syscalls.c        |   4 +-
 kernel/trace/trace_uprobe.c          |   2 +-
 19 files changed, 185 insertions(+), 185 deletions(-)

diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index eda2633a393d..9210a95cb4e6 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -32,7 +32,7 @@
 
 #define OP_BUFFER_FLAGS	0
 
-static struct ring_buffer *op_ring_buffer;
+static struct trace_buffer *op_ring_buffer;
 DEFINE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);
 
 static void wq_sync_buffer(struct work_struct *work);
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 1a40277b512c..df0124eabece 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -6,7 +6,7 @@
 #include <linux/seq_file.h>
 #include <linux/poll.h>
 
-struct ring_buffer;
+struct trace_buffer;
 struct ring_buffer_iter;
 
 /*
@@ -77,13 +77,13 @@ u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event);
  *  else
  *    ring_buffer_unlock_commit(buffer, event);
  */
-void ring_buffer_discard_commit(struct ring_buffer *buffer,
+void ring_buffer_discard_commit(struct trace_buffer *buffer,
 				struct ring_buffer_event *event);
 
 /*
  * size is in bytes for each per CPU buffer.
  */
-struct ring_buffer *
+struct trace_buffer *
 __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key);
 
 /*
@@ -97,38 +97,38 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k
 	__ring_buffer_alloc((size), (flags), &__key);	\
 })
 
-int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full);
-__poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
+int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full);
+__poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 			  struct file *filp, poll_table *poll_table);
 
 
 #define RING_BUFFER_ALL_CPUS -1
 
-void ring_buffer_free(struct ring_buffer *buffer);
+void ring_buffer_free(struct trace_buffer *buffer);
 
-int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, int cpu);
+int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, int cpu);
 
-void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val);
+void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val);
 
-struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer,
+struct ring_buffer_event *ring_buffer_lock_reserve(struct trace_buffer *buffer,
 						   unsigned long length);
-int ring_buffer_unlock_commit(struct ring_buffer *buffer,
+int ring_buffer_unlock_commit(struct trace_buffer *buffer,
 			      struct ring_buffer_event *event);
-int ring_buffer_write(struct ring_buffer *buffer,
+int ring_buffer_write(struct trace_buffer *buffer,
 		      unsigned long length, void *data);
 
-void ring_buffer_nest_start(struct ring_buffer *buffer);
-void ring_buffer_nest_end(struct ring_buffer *buffer);
+void ring_buffer_nest_start(struct trace_buffer *buffer);
+void ring_buffer_nest_end(struct trace_buffer *buffer);
 
 struct ring_buffer_event *
-ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
 		 unsigned long *lost_events);
 struct ring_buffer_event *
-ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts,
 		    unsigned long *lost_events);
 
 struct ring_buffer_iter *
-ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags);
+ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags);
 void ring_buffer_read_prepare_sync(void);
 void ring_buffer_read_start(struct ring_buffer_iter *iter);
 void ring_buffer_read_finish(struct ring_buffer_iter *iter);
@@ -140,59 +140,59 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
 void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
 int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
 
-unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu);
+unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu);
 
-void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
-void ring_buffer_reset(struct ring_buffer *buffer);
+void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu);
+void ring_buffer_reset(struct trace_buffer *buffer);
 
 #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
-int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
-			 struct ring_buffer *buffer_b, int cpu);
+int ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
+			 struct trace_buffer *buffer_b, int cpu);
 #else
 static inline int
-ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
-		     struct ring_buffer *buffer_b, int cpu)
+ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
+		     struct trace_buffer *buffer_b, int cpu)
 {
 	return -ENODEV;
 }
 #endif
 
-bool ring_buffer_empty(struct ring_buffer *buffer);
-bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu);
-
-void ring_buffer_record_disable(struct ring_buffer *buffer);
-void ring_buffer_record_enable(struct ring_buffer *buffer);
-void ring_buffer_record_off(struct ring_buffer *buffer);
-void ring_buffer_record_on(struct ring_buffer *buffer);
-bool ring_buffer_record_is_on(struct ring_buffer *buffer);
-bool ring_buffer_record_is_set_on(struct ring_buffer *buffer);
-void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu);
-void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);
-
-u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu);
-unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu);
-unsigned long ring_buffer_entries(struct ring_buffer *buffer);
-unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
-unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu);
-unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu);
-unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu);
-unsigned long ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu);
-unsigned long ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu);
-
-u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu);
-void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
+bool ring_buffer_empty(struct trace_buffer *buffer);
+bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu);
+
+void ring_buffer_record_disable(struct trace_buffer *buffer);
+void ring_buffer_record_enable(struct trace_buffer *buffer);
+void ring_buffer_record_off(struct trace_buffer *buffer);
+void ring_buffer_record_on(struct trace_buffer *buffer);
+bool ring_buffer_record_is_on(struct trace_buffer *buffer);
+bool ring_buffer_record_is_set_on(struct trace_buffer *buffer);
+void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu);
+void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu);
+
+u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu);
+unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu);
+unsigned long ring_buffer_entries(struct trace_buffer *buffer);
+unsigned long ring_buffer_overruns(struct trace_buffer *buffer);
+unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu);
+unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu);
+unsigned long ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu);
+unsigned long ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu);
+unsigned long ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu);
+
+u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu);
+void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer,
 				      int cpu, u64 *ts);
-void ring_buffer_set_clock(struct ring_buffer *buffer,
+void ring_buffer_set_clock(struct trace_buffer *buffer,
 			   u64 (*clock)(void));
-void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs);
-bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer);
+void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs);
+bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer);
 
-size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu);
-size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu);
+size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu);
+size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu);
 
-void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu);
-void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data);
-int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page,
+void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu);
+void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data);
+int ring_buffer_read_page(struct trace_buffer *buffer, void **data_page,
 			  size_t len, int cpu, int full);
 
 struct trace_seq;
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 4c6e15605766..f20ce342400f 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -153,7 +153,7 @@ void tracing_generic_entry_update(struct trace_entry *entry,
 struct trace_event_file;
 
 struct ring_buffer_event *
-trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
+trace_event_buffer_lock_reserve(struct trace_buffer **current_buffer,
 				struct trace_event_file *trace_file,
 				int type, unsigned long len,
 				unsigned long flags, int pc);
@@ -210,7 +210,7 @@ extern int trace_event_reg(struct trace_event_call *event,
 			    enum trace_reg type, void *data);
 
 struct trace_event_buffer {
-	struct ring_buffer		*buffer;
+	struct trace_buffer		*buffer;
 	struct ring_buffer_event	*event;
 	struct trace_event_file		*trace_file;
 	void				*entry;
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 472b33d23a10..13a58d453992 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -570,7 +570,7 @@ static inline notrace int trace_event_get_offsets_##call(		\
  *	enum event_trigger_type __tt = ETT_NONE;
  *	struct ring_buffer_event *event;
  *	struct trace_event_raw_<call> *entry; <-- defined in stage 1
- *	struct ring_buffer *buffer;
+ *	struct trace_buffer *buffer;
  *	unsigned long irq_flags;
  *	int __data_size;
  *	int pc;
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 2d6e93ab0478..4ee9b78b87cc 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -69,7 +69,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
 {
 	struct blk_io_trace *t;
 	struct ring_buffer_event *event = NULL;
-	struct ring_buffer *buffer = NULL;
+	struct trace_buffer *buffer = NULL;
 	int pc = 0;
 	int cpu = smp_processor_id();
 	bool blk_tracer = blk_tracer_enabled;
@@ -216,7 +216,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 {
 	struct task_struct *tsk = current;
 	struct ring_buffer_event *event = NULL;
-	struct ring_buffer *buffer = NULL;
+	struct trace_buffer *buffer = NULL;
 	struct blk_io_trace *t;
 	unsigned long flags = 0;
 	unsigned long *sequence;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 4bf050fcfe3b..c64360b53f65 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -443,7 +443,7 @@ enum {
 struct ring_buffer_per_cpu {
 	int				cpu;
 	atomic_t			record_disabled;
-	struct ring_buffer		*buffer;
+	struct trace_buffer	*buffer;
 	raw_spinlock_t			reader_lock;	/* serialize readers */
 	arch_spinlock_t			lock;
 	struct lock_class_key		lock_key;
@@ -482,7 +482,7 @@ struct ring_buffer_per_cpu {
 	struct rb_irq_work		irq_work;
 };
 
-struct ring_buffer {
+struct trace_buffer {
 	unsigned			flags;
 	int				cpus;
 	atomic_t			record_disabled;
@@ -518,7 +518,7 @@ struct ring_buffer_iter {
  *
  * Returns the number of pages used by a per_cpu buffer of the ring buffer.
  */
-size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu)
+size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu)
 {
 	return buffer->buffers[cpu]->nr_pages;
 }
@@ -530,7 +530,7 @@ size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu)
  *
  * Returns the number of pages that have content in the ring buffer.
  */
-size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu)
+size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu)
 {
 	size_t read;
 	size_t cnt;
@@ -573,7 +573,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
  * as data is added to any of the @buffer's cpu buffers. Otherwise
  * it will wait for data to be added to a specific cpu buffer.
  */
-int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full)
+int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
 {
 	struct ring_buffer_per_cpu *uninitialized_var(cpu_buffer);
 	DEFINE_WAIT(wait);
@@ -684,7 +684,7 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full)
  * Returns EPOLLIN | EPOLLRDNORM if data exists in the buffers,
  * zero otherwise.
  */
-__poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
+__poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 			  struct file *filp, poll_table *poll_table)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -742,13 +742,13 @@ __poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
-static inline u64 rb_time_stamp(struct ring_buffer *buffer)
+static inline u64 rb_time_stamp(struct trace_buffer *buffer)
 {
 	/* shift to debug/test normalization and TIME_EXTENTS */
 	return buffer->clock() << DEBUG_SHIFT;
 }
 
-u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
+u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu)
 {
 	u64 time;
 
@@ -760,7 +760,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
 }
 EXPORT_SYMBOL_GPL(ring_buffer_time_stamp);
 
-void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
+void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer,
 				      int cpu, u64 *ts)
 {
 	/* Just stupid testing the normalize function and deltas */
@@ -1283,7 +1283,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static struct ring_buffer_per_cpu *
-rb_allocate_cpu_buffer(struct ring_buffer *buffer, long nr_pages, int cpu)
+rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_page *bpage;
@@ -1374,10 +1374,10 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
  * when the buffer wraps. If this flag is not set, the buffer will
  * drop data when the tail hits the head.
  */
-struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
+struct trace_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
 					struct lock_class_key *key)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	long nr_pages;
 	int bsize;
 	int cpu;
@@ -1447,7 +1447,7 @@ EXPORT_SYMBOL_GPL(__ring_buffer_alloc);
  * @buffer: the buffer to free.
  */
 void
-ring_buffer_free(struct ring_buffer *buffer)
+ring_buffer_free(struct trace_buffer *buffer)
 {
 	int cpu;
 
@@ -1463,18 +1463,18 @@ ring_buffer_free(struct ring_buffer *buffer)
 }
 EXPORT_SYMBOL_GPL(ring_buffer_free);
 
-void ring_buffer_set_clock(struct ring_buffer *buffer,
+void ring_buffer_set_clock(struct trace_buffer *buffer,
 			   u64 (*clock)(void))
 {
 	buffer->clock = clock;
 }
 
-void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs)
+void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs)
 {
 	buffer->time_stamp_abs = abs;
 }
 
-bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer)
+bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer)
 {
 	return buffer->time_stamp_abs;
 }
@@ -1712,7 +1712,7 @@ static void update_pages_handler(struct work_struct *work)
  *
  * Returns 0 on success and < 0 on failure.
  */
-int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
+int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
 			int cpu_id)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -1891,7 +1891,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 }
 EXPORT_SYMBOL_GPL(ring_buffer_resize);
 
-void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
+void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val)
 {
 	mutex_lock(&buffer->mutex);
 	if (val)
@@ -2206,7 +2206,7 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
 {
 	struct buffer_page *tail_page = info->tail_page;
 	struct buffer_page *commit_page = cpu_buffer->commit_page;
-	struct ring_buffer *buffer = cpu_buffer->buffer;
+	struct trace_buffer *buffer = cpu_buffer->buffer;
 	struct buffer_page *next_page;
 	int ret;
 
@@ -2609,7 +2609,7 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static __always_inline void
-rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
+rb_wakeups(struct trace_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
 {
 	size_t nr_pages;
 	size_t dirty;
@@ -2733,7 +2733,7 @@ trace_recursive_unlock(struct ring_buffer_per_cpu *cpu_buffer)
  * Call this function before calling another ring_buffer_lock_reserve() and
  * call ring_buffer_nest_end() after the nested ring_buffer_unlock_commit().
  */
-void ring_buffer_nest_start(struct ring_buffer *buffer)
+void ring_buffer_nest_start(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
@@ -2753,7 +2753,7 @@ void ring_buffer_nest_start(struct ring_buffer *buffer)
  * Must be called after ring_buffer_nest_start() and after the
  * ring_buffer_unlock_commit().
  */
-void ring_buffer_nest_end(struct ring_buffer *buffer)
+void ring_buffer_nest_end(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
@@ -2775,7 +2775,7 @@ void ring_buffer_nest_end(struct ring_buffer *buffer)
  *
  * Must be paired with ring_buffer_lock_reserve.
  */
-int ring_buffer_unlock_commit(struct ring_buffer *buffer,
+int ring_buffer_unlock_commit(struct trace_buffer *buffer,
 			      struct ring_buffer_event *event)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -2868,7 +2868,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static __always_inline struct ring_buffer_event *
-rb_reserve_next_event(struct ring_buffer *buffer,
+rb_reserve_next_event(struct trace_buffer *buffer,
 		      struct ring_buffer_per_cpu *cpu_buffer,
 		      unsigned long length)
 {
@@ -2961,7 +2961,7 @@ rb_reserve_next_event(struct ring_buffer *buffer,
  * If NULL is returned, then nothing has been allocated or locked.
  */
 struct ring_buffer_event *
-ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
+ring_buffer_lock_reserve(struct trace_buffer *buffer, unsigned long length)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
@@ -3062,7 +3062,7 @@ rb_decrement_entry(struct ring_buffer_per_cpu *cpu_buffer,
  * If this function is called, do not call ring_buffer_unlock_commit on
  * the event.
  */
-void ring_buffer_discard_commit(struct ring_buffer *buffer,
+void ring_buffer_discard_commit(struct trace_buffer *buffer,
 				struct ring_buffer_event *event)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -3113,7 +3113,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_discard_commit);
  * Note, like ring_buffer_lock_reserve, the length is the length of the data
  * and not the length of the event which would hold the header.
  */
-int ring_buffer_write(struct ring_buffer *buffer,
+int ring_buffer_write(struct trace_buffer *buffer,
 		      unsigned long length,
 		      void *data)
 {
@@ -3193,7 +3193,7 @@ static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
  *
  * The caller should call synchronize_rcu() after this.
  */
-void ring_buffer_record_disable(struct ring_buffer *buffer)
+void ring_buffer_record_disable(struct trace_buffer *buffer)
 {
 	atomic_inc(&buffer->record_disabled);
 }
@@ -3206,7 +3206,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_disable);
  * Note, multiple disables will need the same number of enables
  * to truly enable the writing (much like preempt_disable).
  */
-void ring_buffer_record_enable(struct ring_buffer *buffer)
+void ring_buffer_record_enable(struct trace_buffer *buffer)
 {
 	atomic_dec(&buffer->record_disabled);
 }
@@ -3223,7 +3223,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable);
  * it works like an on/off switch, where as the disable() version
  * must be paired with a enable().
  */
-void ring_buffer_record_off(struct ring_buffer *buffer)
+void ring_buffer_record_off(struct trace_buffer *buffer)
 {
 	unsigned int rd;
 	unsigned int new_rd;
@@ -3246,7 +3246,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_off);
  * it works like an on/off switch, where as the enable() version
  * must be paired with a disable().
  */
-void ring_buffer_record_on(struct ring_buffer *buffer)
+void ring_buffer_record_on(struct trace_buffer *buffer)
 {
 	unsigned int rd;
 	unsigned int new_rd;
@@ -3264,7 +3264,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_on);
  *
  * Returns true if the ring buffer is in a state that it accepts writes.
  */
-bool ring_buffer_record_is_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_on(struct trace_buffer *buffer)
 {
 	return !atomic_read(&buffer->record_disabled);
 }
@@ -3280,7 +3280,7 @@ bool ring_buffer_record_is_on(struct ring_buffer *buffer)
  * ring_buffer_record_disable(), as that is a temporary disabling of
  * the ring buffer.
  */
-bool ring_buffer_record_is_set_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_set_on(struct trace_buffer *buffer)
 {
 	return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF);
 }
@@ -3295,7 +3295,7 @@ bool ring_buffer_record_is_set_on(struct ring_buffer *buffer)
  *
  * The caller should call synchronize_rcu() after this.
  */
-void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3315,7 +3315,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_disable_cpu);
  * Note, multiple disables will need the same number of enables
  * to truly enable the writing (much like preempt_disable).
  */
-void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3345,7 +3345,7 @@ rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer)
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to read from.
  */
-u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu)
+u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu)
 {
 	unsigned long flags;
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -3378,7 +3378,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_oldest_event_ts);
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to read from.
  */
-unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3398,7 +3398,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_bytes_cpu);
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the entries from.
  */
-unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3417,7 +3417,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_entries_cpu);
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the number of overruns from
  */
-unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3440,7 +3440,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_overrun_cpu);
  * @cpu: The per CPU buffer to get the number of overruns from
  */
 unsigned long
-ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3462,7 +3462,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_commit_overrun_cpu);
  * @cpu: The per CPU buffer to get the number of overruns from
  */
 unsigned long
-ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3483,7 +3483,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_dropped_events_cpu);
  * @cpu: The per CPU buffer to get the number of events read
  */
 unsigned long
-ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3502,7 +3502,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_read_events_cpu);
  * Returns the total number of entries in the ring buffer
  * (all CPU entries)
  */
-unsigned long ring_buffer_entries(struct ring_buffer *buffer)
+unsigned long ring_buffer_entries(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long entries = 0;
@@ -3525,7 +3525,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_entries);
  * Returns the total number of overruns in the ring buffer
  * (all CPU entries)
  */
-unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
+unsigned long ring_buffer_overruns(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long overruns = 0;
@@ -3949,7 +3949,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_peek);
 static struct ring_buffer_event *
 rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
 	int nr_loops = 0;
@@ -4077,7 +4077,7 @@ rb_reader_unlock(struct ring_buffer_per_cpu *cpu_buffer, bool locked)
  * not consume the data.
  */
 struct ring_buffer_event *
-ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
 		 unsigned long *lost_events)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
@@ -4141,7 +4141,7 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
  * and eventually empty the ring buffer if the producer is slower.
  */
 struct ring_buffer_event *
-ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts,
 		    unsigned long *lost_events)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -4201,7 +4201,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume);
  * This overall must be paired with ring_buffer_read_finish.
  */
 struct ring_buffer_iter *
-ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags)
+ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_iter *iter;
@@ -4332,7 +4332,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_read);
  * ring_buffer_size - return the size of the ring buffer (in bytes)
  * @buffer: The ring buffer.
  */
-unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu)
 {
 	/*
 	 * Earlier, this method returned
@@ -4398,7 +4398,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
  * @buffer: The ring buffer to reset a per cpu buffer of
  * @cpu: The CPU buffer to be reset
  */
-void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	unsigned long flags;
@@ -4435,7 +4435,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
  * ring_buffer_reset - reset a ring buffer
  * @buffer: The ring buffer to reset all cpu buffers
  */
-void ring_buffer_reset(struct ring_buffer *buffer)
+void ring_buffer_reset(struct trace_buffer *buffer)
 {
 	int cpu;
 
@@ -4448,7 +4448,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset);
  * rind_buffer_empty - is the ring buffer empty?
  * @buffer: The ring buffer to test
  */
-bool ring_buffer_empty(struct ring_buffer *buffer)
+bool ring_buffer_empty(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long flags;
@@ -4478,7 +4478,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_empty);
  * @buffer: The ring buffer
  * @cpu: The CPU buffer to test
  */
-bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
+bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long flags;
@@ -4510,8 +4510,8 @@ EXPORT_SYMBOL_GPL(ring_buffer_empty_cpu);
  * it is expected that the tracer handles the cpu buffer not being
  * used at the moment.
  */
-int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
-			 struct ring_buffer *buffer_b, int cpu)
+int ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
+			 struct trace_buffer *buffer_b, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer_a;
 	struct ring_buffer_per_cpu *cpu_buffer_b;
@@ -4590,7 +4590,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
  * Returns:
  *  The page allocated, or ERR_PTR
  */
-void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu)
+void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_data_page *bpage = NULL;
@@ -4637,7 +4637,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
  *
  * Free a page allocated from ring_buffer_alloc_read_page.
  */
-void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
+void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	struct buffer_data_page *bpage = data;
@@ -4697,7 +4697,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_free_read_page);
  *  >=0 if data has been transferred, returns the offset of consumed data.
  *  <0 if no data has been transferred.
  */
-int ring_buffer_read_page(struct ring_buffer *buffer,
+int ring_buffer_read_page(struct trace_buffer *buffer,
 			  void **data_page, size_t len, int cpu, int full)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
@@ -4868,12 +4868,12 @@ EXPORT_SYMBOL_GPL(ring_buffer_read_page);
  */
 int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	long nr_pages_same;
 	int cpu_i;
 	unsigned long nr_pages;
 
-	buffer = container_of(node, struct ring_buffer, node);
+	buffer = container_of(node, struct trace_buffer, node);
 	if (cpumask_test_cpu(cpu, buffer->cpumask))
 		return 0;
 
@@ -4923,7 +4923,7 @@ int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node)
 static struct task_struct *rb_threads[NR_CPUS] __initdata;
 
 struct rb_test_data {
-	struct ring_buffer	*buffer;
+	struct trace_buffer *buffer;
 	unsigned long		events;
 	unsigned long		bytes_written;
 	unsigned long		bytes_alloc;
@@ -5065,7 +5065,7 @@ static __init int rb_hammer_test(void *arg)
 static __init int test_ringbuffer(void)
 {
 	struct task_struct *rb_hammer;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	int cpu;
 	int ret = 0;
 
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index 32149e46551c..8df0aa810950 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -29,7 +29,7 @@ static int reader_finish;
 static DECLARE_COMPLETION(read_start);
 static DECLARE_COMPLETION(read_done);
 
-static struct ring_buffer *buffer;
+static struct trace_buffer *buffer;
 static struct task_struct *producer;
 static struct task_struct *consumer;
 static unsigned long read;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 23459d53d576..37c63edc4778 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -163,7 +163,7 @@ static union trace_eval_map_item *trace_eval_maps;
 #endif /* CONFIG_TRACE_EVAL_MAP_FILE */
 
 static int tracing_set_tracer(struct trace_array *tr, const char *buf);
-static void ftrace_trace_userstack(struct ring_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_buffer *buffer,
 				   unsigned long flags, int pc);
 
 #define MAX_TRACER_SIZE		100
@@ -338,7 +338,7 @@ int tracing_check_open_get_tr(struct trace_array *tr)
 }
 
 int call_filter_check_discard(struct trace_event_call *call, void *rec,
-			      struct ring_buffer *buffer,
+			      struct trace_buffer *buffer,
 			      struct ring_buffer_event *event)
 {
 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
@@ -747,22 +747,22 @@ static inline void trace_access_lock_init(void)
 #endif
 
 #ifdef CONFIG_STACKTRACE
-static void __ftrace_trace_stack(struct ring_buffer *buffer,
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs);
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs);
 
 #else
-static inline void __ftrace_trace_stack(struct ring_buffer *buffer,
+static inline void __ftrace_trace_stack(struct trace_buffer *buffer,
 					unsigned long flags,
 					int skip, int pc, struct pt_regs *regs)
 {
 }
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs)
 {
@@ -780,7 +780,7 @@ trace_event_setup(struct ring_buffer_event *event,
 }
 
 static __always_inline struct ring_buffer_event *
-__trace_buffer_lock_reserve(struct ring_buffer *buffer,
+__trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags, int pc)
@@ -825,7 +825,7 @@ EXPORT_SYMBOL_GPL(tracing_on);
 
 
 static __always_inline void
-__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
+__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
 {
 	__this_cpu_write(trace_taskinfo_save, true);
 
@@ -848,7 +848,7 @@ __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *eve
 int __trace_puts(unsigned long ip, const char *str, int size)
 {
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
@@ -898,7 +898,7 @@ EXPORT_SYMBOL_GPL(__trace_puts);
 int __trace_bputs(unsigned long ip, const char *str)
 {
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
@@ -1964,7 +1964,7 @@ int __init register_tracer(struct tracer *type)
 
 static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
 {
-	struct ring_buffer *buffer = buf->buffer;
+	struct trace_buffer *buffer = buf->buffer;
 
 	if (!buffer)
 		return;
@@ -1980,7 +1980,7 @@ static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
 
 void tracing_reset_online_cpus(struct trace_buffer *buf)
 {
-	struct ring_buffer *buffer = buf->buffer;
+	struct trace_buffer *buffer = buf->buffer;
 	int cpu;
 
 	if (!buffer)
@@ -2098,7 +2098,7 @@ int is_tracing_stopped(void)
  */
 void tracing_start(void)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	if (tracing_disabled)
@@ -2135,7 +2135,7 @@ void tracing_start(void)
 
 static void tracing_start_tr(struct trace_array *tr)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	if (tracing_disabled)
@@ -2172,7 +2172,7 @@ static void tracing_start_tr(struct trace_array *tr)
  */
 void tracing_stop(void)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
@@ -2200,7 +2200,7 @@ void tracing_stop(void)
 
 static void tracing_stop_tr(struct trace_array *tr)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	/* If global, we need to also stop the max tracer */
@@ -2442,7 +2442,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned short type,
 EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
 
 struct ring_buffer_event *
-trace_buffer_lock_reserve(struct ring_buffer *buffer,
+trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags, int pc)
@@ -2561,10 +2561,10 @@ void trace_buffered_event_disable(void)
 	preempt_enable();
 }
 
-static struct ring_buffer *temp_buffer;
+static struct trace_buffer *temp_buffer;
 
 struct ring_buffer_event *
-trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
+trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 			  struct trace_event_file *trace_file,
 			  int type, unsigned long len,
 			  unsigned long flags, int pc)
@@ -2689,7 +2689,7 @@ EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
 # define STACK_SKIP 3
 
 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event,
 				     unsigned long flags, int pc,
 				     struct pt_regs *regs)
@@ -2710,7 +2710,7 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr,
  * Similar to trace_buffer_unlock_commit_regs() but do not dump stack.
  */
 void
-trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 				   struct ring_buffer_event *event)
 {
 	__buffer_unlock_commit(buffer, event);
@@ -2845,7 +2845,7 @@ trace_function(struct trace_array *tr,
 	       int pc)
 {
 	struct trace_event_call *call = &event_function;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ftrace_entry *entry;
 
@@ -2883,7 +2883,7 @@ struct ftrace_stacks {
 static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks);
 static DEFINE_PER_CPU(int, ftrace_stack_reserve);
 
-static void __ftrace_trace_stack(struct ring_buffer *buffer,
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs)
 {
@@ -2958,7 +2958,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
 }
 
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs)
 {
@@ -2971,7 +2971,7 @@ static inline void ftrace_trace_stack(struct trace_array *tr,
 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 		   int pc)
 {
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 
 	if (rcu_is_watching()) {
 		__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
@@ -3018,7 +3018,7 @@ EXPORT_SYMBOL_GPL(trace_dump_stack);
 static DEFINE_PER_CPU(int, user_stack_count);
 
 static void
-ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
+ftrace_trace_userstack(struct trace_buffer *buffer, unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_user_stack;
 	struct ring_buffer_event *event;
@@ -3063,7 +3063,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 	preempt_enable();
 }
 #else /* CONFIG_USER_STACKTRACE_SUPPORT */
-static void ftrace_trace_userstack(struct ring_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_buffer *buffer,
 				   unsigned long flags, int pc)
 {
 }
@@ -3188,7 +3188,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 {
 	struct trace_event_call *call = &event_bprint;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct trace_array *tr = &global_trace;
 	struct bprint_entry *entry;
 	unsigned long flags;
@@ -3245,7 +3245,7 @@ EXPORT_SYMBOL_GPL(trace_vbprintk);
 
 __printf(3, 0)
 static int
-__trace_array_vprintk(struct ring_buffer *buffer,
+__trace_array_vprintk(struct trace_buffer *buffer,
 		      unsigned long ip, const char *fmt, va_list args)
 {
 	struct trace_event_call *call = &event_print;
@@ -3326,7 +3326,7 @@ int trace_array_printk(struct trace_array *tr,
 EXPORT_SYMBOL_GPL(trace_array_printk);
 
 __printf(3, 4)
-int trace_array_printk_buf(struct ring_buffer *buffer,
+int trace_array_printk_buf(struct trace_buffer *buffer,
 			   unsigned long ip, const char *fmt, ...)
 {
 	int ret;
@@ -3382,7 +3382,7 @@ static struct trace_entry *
 __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
 		  unsigned long *missing_events, u64 *ent_ts)
 {
-	struct ring_buffer *buffer = iter->trace_buffer->buffer;
+	struct trace_buffer *buffer = iter->trace_buffer->buffer;
 	struct trace_entry *ent, *next = NULL;
 	unsigned long lost_events = 0, next_lost = 0;
 	int cpu_file = iter->cpu_file;
@@ -6464,7 +6464,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	struct trace_array *tr = filp->private_data;
 	struct ring_buffer_event *event;
 	enum event_trigger_type tt = ETT_NONE;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	ssize_t written;
@@ -6544,7 +6544,7 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
 {
 	struct trace_array *tr = filp->private_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct raw_data_entry *entry;
 	unsigned long irq_flags;
 	ssize_t written;
@@ -7427,7 +7427,7 @@ static int tracing_buffers_release(struct inode *inode, struct file *file)
 }
 
 struct buffer_ref {
-	struct ring_buffer	*buffer;
+	struct trace_buffer	*buffer;
 	void			*page;
 	int			cpu;
 	refcount_t		refcount;
@@ -8264,7 +8264,7 @@ rb_simple_write(struct file *filp, const char __user *ubuf,
 		size_t cnt, loff_t *ppos)
 {
 	struct trace_array *tr = filp->private_data;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	unsigned long val;
 	int ret;
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 63bf60f79398..308fcd673102 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -178,7 +178,7 @@ struct trace_option_dentry;
 
 struct trace_buffer {
 	struct trace_array		*tr;
-	struct ring_buffer		*buffer;
+	struct trace_buffer		*buffer;
 	struct trace_array_cpu __percpu	*data;
 	u64				time_start;
 	int				cpu;
@@ -705,7 +705,7 @@ struct dentry *tracing_init_dentry(void);
 struct ring_buffer_event;
 
 struct ring_buffer_event *
-trace_buffer_lock_reserve(struct ring_buffer *buffer,
+trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags,
@@ -717,7 +717,7 @@ struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 					  int *ent_cpu, u64 *ent_ts);
 
-void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 					struct ring_buffer_event *event);
 
 int trace_empty(struct trace_iterator *iter);
@@ -873,7 +873,7 @@ trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 extern int
 trace_array_vprintk(struct trace_array *tr,
 		    unsigned long ip, const char *fmt, va_list args);
-int trace_array_printk_buf(struct ring_buffer *buffer,
+int trace_array_printk_buf(struct trace_buffer *buffer,
 			   unsigned long ip, const char *fmt, ...);
 void trace_printk_seq(struct trace_seq *s);
 enum print_line_t print_trace_line(struct trace_iterator *iter);
@@ -1367,17 +1367,17 @@ struct trace_subsystem_dir {
 };
 
 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event);
 
 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event,
 				     unsigned long flags, int pc,
 				     struct pt_regs *regs);
 
 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
-					      struct ring_buffer *buffer,
+					      struct trace_buffer *buffer,
 					      struct ring_buffer_event *event,
 					      unsigned long flags, int pc)
 {
@@ -1390,7 +1390,7 @@ void trace_buffered_event_disable(void);
 void trace_buffered_event_enable(void);
 
 static inline void
-__trace_event_discard_commit(struct ring_buffer *buffer,
+__trace_event_discard_commit(struct trace_buffer *buffer,
 			     struct ring_buffer_event *event)
 {
 	if (this_cpu_read(trace_buffered_event) == event) {
@@ -1416,7 +1416,7 @@ __trace_event_discard_commit(struct ring_buffer *buffer,
  */
 static inline bool
 __event_trigger_test_discard(struct trace_event_file *file,
-			     struct ring_buffer *buffer,
+			     struct trace_buffer *buffer,
 			     struct ring_buffer_event *event,
 			     void *entry,
 			     enum event_trigger_type *tt)
@@ -1451,7 +1451,7 @@ __event_trigger_test_discard(struct trace_event_file *file,
  */
 static inline void
 event_trigger_unlock_commit(struct trace_event_file *file,
-			    struct ring_buffer *buffer,
+			    struct trace_buffer *buffer,
 			    struct ring_buffer_event *event,
 			    void *entry, unsigned long irq_flags, int pc)
 {
@@ -1482,7 +1482,7 @@ event_trigger_unlock_commit(struct trace_event_file *file,
  */
 static inline void
 event_trigger_unlock_commit_regs(struct trace_event_file *file,
-				 struct ring_buffer *buffer,
+				 struct trace_buffer *buffer,
 				 struct ring_buffer_event *event,
 				 void *entry, unsigned long irq_flags, int pc,
 				 struct pt_regs *regs)
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 88e158d27965..b291e0422191 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -32,10 +32,10 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect)
 {
 	struct trace_event_call *call = &event_branch;
 	struct trace_array *tr = branch_tracer;
+	struct trace_buffer *buffer;
 	struct trace_array_cpu *data;
 	struct ring_buffer_event *event;
 	struct trace_branch *entry;
-	struct ring_buffer *buffer;
 	unsigned long flags;
 	int pc;
 	const char *p;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index c6de3cebc127..fbf49873888d 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -3391,8 +3391,8 @@ static void __init
 function_test_events_call(unsigned long ip, unsigned long parent_ip,
 			  struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	struct ftrace_entry *entry;
 	unsigned long flags;
 	long disabled;
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f49d1a36d3ae..df009a251c05 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -879,7 +879,7 @@ static notrace void trace_event_raw_event_synth(void *__data,
 	struct trace_event_file *trace_file = __data;
 	struct synth_trace_event *entry;
 	struct trace_event_buffer fbuffer;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct synth_event *event;
 	unsigned int i, n_u64;
 	int fields_size = 0;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 78af97163147..e6b9b1169a48 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -101,7 +101,7 @@ int __trace_graph_entry(struct trace_array *tr,
 {
 	struct trace_event_call *call = &event_funcgraph_entry;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ftrace_graph_ent_entry *entry;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
@@ -221,7 +221,7 @@ void __trace_graph_return(struct trace_array *tr,
 {
 	struct trace_event_call *call = &event_funcgraph_exit;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ftrace_graph_ret_entry *entry;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 6638d63f0921..cb8da2a20f59 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -104,7 +104,7 @@ static void trace_hwlat_sample(struct hwlat_sample *sample)
 {
 	struct trace_array *tr = hwlat_trace;
 	struct trace_event_call *call = &event_hwlat;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct hwlat_entry *entry;
 	unsigned long flags;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7f890262c8a3..477b6b011e7d 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1175,8 +1175,8 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 		    struct trace_event_file *trace_file)
 {
 	struct kprobe_trace_entry_head *entry;
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	int size, dsize, pc;
 	unsigned long irq_flags;
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
@@ -1223,8 +1223,8 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 		       struct trace_event_file *trace_file)
 {
 	struct kretprobe_trace_entry_head *entry;
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	int size, pc, dsize;
 	unsigned long irq_flags;
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b0388016b687..a03e8859e094 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -297,7 +297,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
 				struct mmiotrace_rw *rw)
 {
 	struct trace_event_call *call = &event_mmiotrace_rw;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_rw *entry;
 	int pc = preempt_count();
@@ -327,7 +327,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
 				struct mmiotrace_map *map)
 {
 	struct trace_event_call *call = &event_mmiotrace_map;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_map *entry;
 	int pc = preempt_count();
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 5e43b9664eca..0fe78a8b2e86 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -378,7 +378,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
 			   unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_context_switch;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
 
@@ -408,7 +408,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
 	struct trace_event_call *call = &event_wakeup;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->trace_buffer.buffer;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_WAKE,
 					  sizeof(*entry), flags, pc);
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 16fa218556fa..581b4a11b657 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -317,7 +317,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long irq_flags;
 	unsigned long args[6];
 	int pc;
@@ -367,7 +367,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long irq_flags;
 	int pc;
 	int syscall_nr;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 352073d36585..6c75d94f5c2f 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -938,8 +938,8 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
 				struct trace_event_file *trace_file)
 {
 	struct uprobe_trace_entry_head *entry;
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	void *data;
 	int size, esize;
 	struct trace_event_call *call = trace_probe_event_call(&tu->tp);
-- 
2.20.1

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Jiri Olsa]

On Fri, Dec 13, 2019 at 02:05:31PM -0500, Steven Rostedt wrote:

SNIP

>  	struct trace_array *tr = filp->private_data;
> -	struct ring_buffer *buffer = tr->trace_buffer.buffer;
> +	struct trace_buffer *buffer = tr->trace_buffer.buffer;
>  	unsigned long val;
>  	int ret;
>  
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index 63bf60f79398..308fcd673102 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -178,7 +178,7 @@ struct trace_option_dentry;
>  
>  struct trace_buffer {
>  	struct trace_array		*tr;
> -	struct ring_buffer		*buffer;
> +	struct trace_buffer		*buffer;

perf change is fine, but 'trace_buffer' won't work because
we already have 'struct trace_buffer' defined in here

maybe we could change this name to trace_buffer_array?

thanks,
jirka

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Jiri Olsa]

On Sat, Dec 14, 2019 at 12:35:10PM +0100, Jiri Olsa wrote:
> On Fri, Dec 13, 2019 at 02:05:31PM -0500, Steven Rostedt wrote:
> 
> SNIP
> 
> >  	struct trace_array *tr = filp->private_data;
> > -	struct ring_buffer *buffer = tr->trace_buffer.buffer;
> > +	struct trace_buffer *buffer = tr->trace_buffer.buffer;
> >  	unsigned long val;
> >  	int ret;
> >  
> > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> > index 63bf60f79398..308fcd673102 100644
> > --- a/kernel/trace/trace.h
> > +++ b/kernel/trace/trace.h
> > @@ -178,7 +178,7 @@ struct trace_option_dentry;
> >  
> >  struct trace_buffer {
> >  	struct trace_array		*tr;
> > -	struct ring_buffer		*buffer;
> > +	struct trace_buffer		*buffer;
> 
> perf change is fine, but 'trace_buffer' won't work because
> we already have 'struct trace_buffer' defined in here
> 
> maybe we could change this name to trace_buffer_array?

..like in patch below? it's independent of your previous changes

jirka


---
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 4c6e15605766..05588dafd3dc 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -79,7 +79,7 @@ struct trace_entry {
 struct trace_iterator {
 	struct trace_array	*tr;
 	struct tracer		*trace;
-	struct trace_buffer	*trace_buffer;
+	struct trace_buffer_array *trace_buffer;
 	void			*private;
 	int			cpu_file;
 	struct mutex		mutex;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 23459d53d576..9abee8bf831c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -603,7 +603,7 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
 	return read;
 }
 
-static u64 buffer_ftrace_now(struct trace_buffer *buf, int cpu)
+static u64 buffer_ftrace_now(struct trace_buffer_array *buf, int cpu)
 {
 	u64 ts;
 
@@ -1036,9 +1036,9 @@ void *tracing_cond_snapshot_data(struct trace_array *tr)
 }
 EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
 
-static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
-					struct trace_buffer *size_buf, int cpu_id);
-static void set_buffer_entries(struct trace_buffer *buf, unsigned long val);
+static int resize_buffer_duplicate_size(struct trace_buffer_array *trace_buf,
+					struct trace_buffer_array *size_buf, int cpu_id);
+static void set_buffer_entries(struct trace_buffer_array *buf, unsigned long val);
 
 int tracing_alloc_snapshot_instance(struct trace_array *tr)
 {
@@ -1590,8 +1590,8 @@ void latency_fsnotify(struct trace_array *tr)
 static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-	struct trace_buffer *trace_buf = &tr->trace_buffer;
-	struct trace_buffer *max_buf = &tr->max_buffer;
+	struct trace_buffer_array *trace_buf = &tr->trace_buffer;
+	struct trace_buffer_array *max_buf = &tr->max_buffer;
 	struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
 	struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);
 
@@ -1962,7 +1962,7 @@ int __init register_tracer(struct tracer *type)
 	return ret;
 }
 
-static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
+static void tracing_reset_cpu(struct trace_buffer_array *buf, int cpu)
 {
 	struct ring_buffer *buffer = buf->buffer;
 
@@ -1978,7 +1978,7 @@ static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
 	ring_buffer_record_enable(buffer);
 }
 
-void tracing_reset_online_cpus(struct trace_buffer *buf)
+void tracing_reset_online_cpus(struct trace_buffer_array *buf)
 {
 	struct ring_buffer *buffer = buf->buffer;
 	int cpu;
@@ -3602,7 +3602,7 @@ static void s_stop(struct seq_file *m, void *p)
 }
 
 static void
-get_total_entries_cpu(struct trace_buffer *buf, unsigned long *total,
+get_total_entries_cpu(struct trace_buffer_array *buf, unsigned long *total,
 		      unsigned long *entries, int cpu)
 {
 	unsigned long count;
@@ -3624,7 +3624,7 @@ get_total_entries_cpu(struct trace_buffer *buf, unsigned long *total,
 }
 
 static void
-get_total_entries(struct trace_buffer *buf,
+get_total_entries(struct trace_buffer_array *buf,
 		  unsigned long *total, unsigned long *entries)
 {
 	unsigned long t, e;
@@ -3676,7 +3676,7 @@ static void print_lat_help_header(struct seq_file *m)
 		    "#     \\   /      |||||  \\    |   /         \n");
 }
 
-static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
+static void print_event_info(struct trace_buffer_array *buf, struct seq_file *m)
 {
 	unsigned long total;
 	unsigned long entries;
@@ -3687,7 +3687,7 @@ static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
 	seq_puts(m, "#\n");
 }
 
-static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
+static void print_func_help_header(struct trace_buffer_array *buf, struct seq_file *m,
 				   unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
@@ -3698,7 +3698,7 @@ static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
 	seq_printf(m, "#              | |     %s    |       |         |\n",	 tgid ? "  |      " : "");
 }
 
-static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m,
+static void print_func_help_header_irq(struct trace_buffer_array *buf, struct seq_file *m,
 				       unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
@@ -3720,7 +3720,7 @@ void
 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 {
 	unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
-	struct trace_buffer *buf = iter->trace_buffer;
+	struct trace_buffer_array *buf = iter->trace_buffer;
 	struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
 	struct tracer *type = iter->trace;
 	unsigned long entries;
@@ -4357,7 +4357,7 @@ static int tracing_open(struct inode *inode, struct file *file)
 	/* If this file was open for write, then erase contents */
 	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 		int cpu = tracing_get_cpu(inode);
-		struct trace_buffer *trace_buf = &tr->trace_buffer;
+		struct trace_buffer_array *trace_buf = &tr->trace_buffer;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 		if (tr->current_trace->print_max)
@@ -5532,7 +5532,7 @@ int tracer_init(struct tracer *t, struct trace_array *tr)
 	return t->init(tr);
 }
 
-static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
+static void set_buffer_entries(struct trace_buffer_array *buf, unsigned long val)
 {
 	int cpu;
 
@@ -5542,8 +5542,8 @@ static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 /* resize @tr's buffer to the size of @size_tr's entries */
-static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
-					struct trace_buffer *size_buf, int cpu_id)
+static int resize_buffer_duplicate_size(struct trace_buffer_array *trace_buf,
+					struct trace_buffer_array *size_buf, int cpu_id)
 {
 	int cpu, ret = 0;
 
@@ -7607,7 +7607,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 {
 	struct inode *inode = file_inode(filp);
 	struct trace_array *tr = inode->i_private;
-	struct trace_buffer *trace_buf = &tr->trace_buffer;
+	struct trace_buffer_array *trace_buf = &tr->trace_buffer;
 	int cpu = tracing_get_cpu(inode);
 	struct trace_seq *s;
 	unsigned long cnt;
@@ -8354,7 +8354,7 @@ static void
 init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
 
 static int
-allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
+allocate_trace_buffer(struct trace_array *tr, struct trace_buffer_array *buf, int size)
 {
 	enum ring_buffer_flags rb_flags;
 
@@ -8409,7 +8409,7 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
 	return 0;
 }
 
-static void free_trace_buffer(struct trace_buffer *buf)
+static void free_trace_buffer(struct trace_buffer_array *buf)
 {
 	if (buf->buffer) {
 		ring_buffer_free(buf->buffer);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 63bf60f79398..01d0ab7de131 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -176,7 +176,7 @@ struct trace_array_cpu {
 struct tracer;
 struct trace_option_dentry;
 
-struct trace_buffer {
+struct trace_buffer_array {
 	struct trace_array		*tr;
 	struct ring_buffer		*buffer;
 	struct trace_array_cpu __percpu	*data;
@@ -247,9 +247,9 @@ struct cond_snapshot {
  * They have on/off state as well:
  */
 struct trace_array {
-	struct list_head	list;
-	char			*name;
-	struct trace_buffer	trace_buffer;
+	struct list_head		list;
+	char				*name;
+	struct trace_buffer_array	trace_buffer;
 #ifdef CONFIG_TRACER_MAX_TRACE
 	/*
 	 * The max_buffer is used to snapshot the trace when a maximum
@@ -262,8 +262,8 @@ struct trace_array {
 	 * with the buffer of the trace_buffer and the buffers are reset for
 	 * the trace_buffer so the tracing can continue.
 	 */
-	struct trace_buffer	max_buffer;
-	bool			allocated_snapshot;
+	struct trace_buffer_array	max_buffer;
+	bool				allocated_snapshot;
 #endif
 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
 	unsigned long		max_latency;
@@ -685,7 +685,7 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
-void tracing_reset_online_cpus(struct trace_buffer *buf);
+void tracing_reset_online_cpus(struct trace_buffer_array *buf);
 void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 69ee8ef12cee..d9fc1e0cd8d1 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -23,7 +23,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
 	return 0;
 }
 
-static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
+static int trace_test_buffer_cpu(struct trace_buffer_array *buf, int cpu)
 {
 	struct ring_buffer_event *event;
 	struct trace_entry *entry;
@@ -60,7 +60,7 @@ static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
  * Test the trace buffer to see if all the elements
  * are still sane.
  */
-static int __maybe_unused trace_test_buffer(struct trace_buffer *buf, unsigned long *count)
+static int __maybe_unused trace_test_buffer(struct trace_buffer_array *buf, unsigned long *count)
 {
 	unsigned long flags, cnt = 0;
 	int cpu, ret = 0;

Re: [RFC] btf: Some structs are doubled because of struct ring_buffer

[Steven Rostedt]

On Wed, 18 Dec 2019 17:14:01 +0100
Jiri Olsa <jolsa@redhat.com> wrote:

> On Sat, Dec 14, 2019 at 12:35:10PM +0100, Jiri Olsa wrote:
> > On Fri, Dec 13, 2019 at 02:05:31PM -0500, Steven Rostedt wrote:
> > 
> > SNIP
> >   
> > >  	struct trace_array *tr = filp->private_data;
> > > -	struct ring_buffer *buffer = tr->trace_buffer.buffer;
> > > +	struct trace_buffer *buffer = tr->trace_buffer.buffer;
> > >  	unsigned long val;
> > >  	int ret;
> > >  
> > > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> > > index 63bf60f79398..308fcd673102 100644
> > > --- a/kernel/trace/trace.h
> > > +++ b/kernel/trace/trace.h
> > > @@ -178,7 +178,7 @@ struct trace_option_dentry;
> > >  
> > >  struct trace_buffer {
> > >  	struct trace_array		*tr;
> > > -	struct ring_buffer		*buffer;
> > > +	struct trace_buffer		*buffer;  
> > 
> > perf change is fine, but 'trace_buffer' won't work because
> > we already have 'struct trace_buffer' defined in here
> > 
> > maybe we could change this name to trace_buffer_array?  
> 
> ..like in patch below? it's independent of your previous changes
> 
>

Actually, I would prefer to call it either trace_array_buffer, or just
array_buffer.

-- Steve