Commit 6844c09d authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf events: Separate the routines handling the PERF_SAMPLE_ identity fields 



Those will be made available in sample like events like MMAP, EXEC, etc in a
followup patch. So precalculate the extra id header space and have a separate
routine to fill them up.

V2: Thomas noticed that the id header needs to be precalculated at
inherit_events too:

LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6>

Tested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1291318772-30880-2-git-send-email-acme@infradead.org>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 614b6780

include/linux/perf_event.h

+1 −0
Original line number Diff line number Diff line
@@ -759,6 +759,7 @@ struct perf_event { 


	struct perf_event_attr		attr;

	u16				header_size;

	u16				id_header_size;

	u16				read_size;

	struct hw_perf_event		hw;

kernel/perf_event.c

+75 −54
Original line number Diff line number Diff line
@@ -133,6 +133,28 @@ static void unclone_ctx(struct perf_event_context *ctx) 
	}

}



static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)

{

	/*

	 * only top level events have the pid namespace they were created in

	 */

	if (event->parent)

		event = event->parent;



	return task_tgid_nr_ns(p, event->ns);

}



static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)

{

	/*

	 * only top level events have the pid namespace they were created in

	 */

	if (event->parent)

		event = event->parent;



	return task_pid_nr_ns(p, event->ns);

}



/*

 * If we inherit events we want to return the parent event id

 * to userspace.
@@ -351,15 +373,30 @@ static void perf_event__header_size(struct perf_event *event) 
	if (sample_type & PERF_SAMPLE_IP)

		size += sizeof(data->ip);



	if (sample_type & PERF_SAMPLE_ADDR)

		size += sizeof(data->addr);



	if (sample_type & PERF_SAMPLE_PERIOD)

		size += sizeof(data->period);



	if (sample_type & PERF_SAMPLE_READ)

		size += event->read_size;



	event->header_size = size;

}



static void perf_event__id_header_size(struct perf_event *event)

{

	struct perf_sample_data *data;

	u64 sample_type = event->attr.sample_type;

	u16 size = 0;



	if (sample_type & PERF_SAMPLE_TID)

		size += sizeof(data->tid_entry);



	if (sample_type & PERF_SAMPLE_TIME)

		size += sizeof(data->time);



	if (sample_type & PERF_SAMPLE_ADDR)

		size += sizeof(data->addr);



	if (sample_type & PERF_SAMPLE_ID)

		size += sizeof(data->id);
@@ -369,13 +406,7 @@ static void perf_event__header_size(struct perf_event *event) 
	if (sample_type & PERF_SAMPLE_CPU)

		size += sizeof(data->cpu_entry);



	if (sample_type & PERF_SAMPLE_PERIOD)

		size += sizeof(data->period);



	if (sample_type & PERF_SAMPLE_READ)

		size += event->read_size;



	event->header_size = size;

	event->id_header_size = size;

}



static void perf_group_attach(struct perf_event *event)
@@ -3357,6 +3388,36 @@ __always_inline void perf_output_copy(struct perf_output_handle *handle, 
	} while (len);

}



static void perf_event_header__init_id(struct perf_event_header *header,

				       struct perf_sample_data *data,

				       struct perf_event *event)

{

	u64 sample_type = event->attr.sample_type;



	data->type = sample_type;

	header->size += event->id_header_size;



	if (sample_type & PERF_SAMPLE_TID) {

		/* namespace issues */

		data->tid_entry.pid = perf_event_pid(event, current);

		data->tid_entry.tid = perf_event_tid(event, current);

	}



	if (sample_type & PERF_SAMPLE_TIME)

		data->time = perf_clock();



	if (sample_type & PERF_SAMPLE_ID)

		data->id = primary_event_id(event);



	if (sample_type & PERF_SAMPLE_STREAM_ID)

		data->stream_id = event->id;



	if (sample_type & PERF_SAMPLE_CPU) {

		data->cpu_entry.cpu	 = raw_smp_processor_id();

		data->cpu_entry.reserved = 0;

	}

}



int perf_output_begin(struct perf_output_handle *handle,

		      struct perf_event *event, unsigned int size,

		      int nmi, int sample)
@@ -3459,28 +3520,6 @@ void perf_output_end(struct perf_output_handle *handle) 
	rcu_read_unlock();

}



static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)

{

	/*

	 * only top level events have the pid namespace they were created in

	 */

	if (event->parent)

		event = event->parent;



	return task_tgid_nr_ns(p, event->ns);

}



static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)

{

	/*

	 * only top level events have the pid namespace they were created in

	 */

	if (event->parent)

		event = event->parent;



	return task_pid_nr_ns(p, event->ns);

}



static void perf_output_read_one(struct perf_output_handle *handle,

				 struct perf_event *event,

				 u64 enabled, u64 running)
@@ -3655,37 +3694,17 @@ void perf_prepare_sample(struct perf_event_header *header, 
{

	u64 sample_type = event->attr.sample_type;



	data->type = sample_type;



	header->type = PERF_RECORD_SAMPLE;

	header->size = sizeof(*header) + event->header_size;



	header->misc = 0;

	header->misc |= perf_misc_flags(regs);



	perf_event_header__init_id(header, data, event);



	if (sample_type & PERF_SAMPLE_IP)

		data->ip = perf_instruction_pointer(regs);



	if (sample_type & PERF_SAMPLE_TID) {

		/* namespace issues */

		data->tid_entry.pid = perf_event_pid(event, current);

		data->tid_entry.tid = perf_event_tid(event, current);

	}



	if (sample_type & PERF_SAMPLE_TIME)

		data->time = perf_clock();



	if (sample_type & PERF_SAMPLE_ID)

		data->id = primary_event_id(event);



	if (sample_type & PERF_SAMPLE_STREAM_ID)

		data->stream_id = event->id;



	if (sample_type & PERF_SAMPLE_CPU) {

		data->cpu_entry.cpu		= raw_smp_processor_id();

		data->cpu_entry.reserved	= 0;

	}



	if (sample_type & PERF_SAMPLE_CALLCHAIN) {

		int size = 1;
@@ -5745,6 +5764,7 @@ SYSCALL_DEFINE5(perf_event_open, 
	 * Precalculate sample_data sizes

	 */

	perf_event__header_size(event);

	perf_event__id_header_size(event);



	/*

	 * Drop the reference on the group_event after placing the
@@ -6102,6 +6122,7 @@ inherit_event(struct perf_event *parent_event, 
	 * Precalculate sample_data sizes

	 */

	perf_event__header_size(child_event);

	perf_event__id_header_size(child_event);



	/*

	 * Link it up in the child's context:

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