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Commit 3dab77fb authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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perf: Rework/fix the whole read vs group stuff 

Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce
PERF_FORMAT_GROUP to deal with group reads in a more generic
way.

This allows you to get group reads out of read() as well.
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.117411814@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent bcfc2602
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Showing with 238 additions and 83 deletions
include/linux/perf_counter.h
View file @ 3dab77fb
......@@ -115,7 +115,7 @@ enum perf_counter_sample_format {
PERF_SAMPLE_TID = 1U << 1,
PERF_SAMPLE_TIME = 1U << 2,
PERF_SAMPLE_ADDR = 1U << 3,
PERF_SAMPLE_GROUP = 1U << 4,
PERF_SAMPLE_READ = 1U << 4,
PERF_SAMPLE_CALLCHAIN = 1U << 5,
PERF_SAMPLE_ID = 1U << 6,
PERF_SAMPLE_CPU = 1U << 7,
......@@ -127,16 +127,32 @@ enum perf_counter_sample_format {
};
/*
* Bits that can be set in attr.read_format to request that
* reads on the counter should return the indicated quantities,
* in increasing order of bit value, after the counter value.
* The format of the data returned by read() on a perf counter fd,
* as specified by attr.read_format:
*
* struct read_format {
* { u64 value;
* { u64 time_enabled; } && PERF_FORMAT_ENABLED
* { u64 time_running; } && PERF_FORMAT_RUNNING
* { u64 id; } && PERF_FORMAT_ID
* } && !PERF_FORMAT_GROUP
*
* { u64 nr;
* { u64 time_enabled; } && PERF_FORMAT_ENABLED
* { u64 time_running; } && PERF_FORMAT_RUNNING
* { u64 value;
* { u64 id; } && PERF_FORMAT_ID
* } cntr[nr];
* } && PERF_FORMAT_GROUP
* };
*/
enum perf_counter_read_format {
PERF_FORMAT_TOTAL_TIME_ENABLED = 1U << 0,
PERF_FORMAT_TOTAL_TIME_RUNNING = 1U << 1,
PERF_FORMAT_ID = 1U << 2,
PERF_FORMAT_GROUP = 1U << 3,
PERF_FORMAT_MAX = 1U << 3, /* non-ABI */
PERF_FORMAT_MAX = 1U << 4, /* non-ABI */
};
#define PERF_ATTR_SIZE_VER0 64 /* sizeof first published struct */
......@@ -343,10 +359,8 @@ enum perf_event_type {
* struct {
* struct perf_event_header header;
* u32 pid, tid;
* u64 value;
* { u64 time_enabled; } && PERF_FORMAT_ENABLED
* { u64 time_running; } && PERF_FORMAT_RUNNING
* { u64 parent_id; } && PERF_FORMAT_ID
*
* struct read_format values;
* };
*/
PERF_EVENT_READ = 8,
......@@ -364,11 +378,22 @@ enum perf_event_type {
* { u32 cpu, res; } && PERF_SAMPLE_CPU
* { u64 period; } && PERF_SAMPLE_PERIOD
*
* { u64 nr;
* { u64 id, val; } cnt[nr]; } && PERF_SAMPLE_GROUP
* { struct read_format values; } && PERF_SAMPLE_READ
*
* { u64 nr,
* u64 ips[nr]; } && PERF_SAMPLE_CALLCHAIN
*
* #
* # The RAW record below is opaque data wrt the ABI
* #
* # That is, the ABI doesn't make any promises wrt to
* # the stability of its content, it may vary depending
* # on event, hardware, kernel version and phase of
* # the moon.
* #
* # In other words, PERF_SAMPLE_RAW contents are not an ABI.
* #
*
* { u32 size;
* char data[size];}&& PERF_SAMPLE_RAW
* };
......
kernel/perf_counter.c
View file @ 3dab77fb
......@@ -1692,7 +1692,32 @@ static int perf_release(struct inode *inode, struct file *file)
return 0;
}
static u64 perf_counter_read_tree(struct perf_counter *counter)
static int perf_counter_read_size(struct perf_counter *counter)
{
int entry = sizeof(u64); /* value */
int size = 0;
int nr = 1;
if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
size += sizeof(u64);
if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
size += sizeof(u64);
if (counter->attr.read_format & PERF_FORMAT_ID)
entry += sizeof(u64);
if (counter->attr.read_format & PERF_FORMAT_GROUP) {
nr += counter->group_leader->nr_siblings;
size += sizeof(u64);
}
size += entry * nr;
return size;
}
static u64 perf_counter_read_value(struct perf_counter *counter)
{
struct perf_counter *child;
u64 total = 0;
......@@ -1704,14 +1729,96 @@ static u64 perf_counter_read_tree(struct perf_counter *counter)
return total;
}
static int perf_counter_read_entry(struct perf_counter *counter,
u64 read_format, char __user *buf)
{
int n = 0, count = 0;
u64 values[2];
values[n++] = perf_counter_read_value(counter);
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_counter_id(counter);
count = n * sizeof(u64);
if (copy_to_user(buf, values, count))
return -EFAULT;
return count;
}
static int perf_counter_read_group(struct perf_counter *counter,
u64 read_format, char __user *buf)
{
struct perf_counter *leader = counter->group_leader, *sub;
int n = 0, size = 0, err = -EFAULT;
u64 values[3];
values[n++] = 1 + leader->nr_siblings;
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
values[n++] = leader->total_time_enabled +
atomic64_read(&leader->child_total_time_enabled);
}
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
values[n++] = leader->total_time_running +
atomic64_read(&leader->child_total_time_running);
}
size = n * sizeof(u64);
if (copy_to_user(buf, values, size))
return -EFAULT;
err = perf_counter_read_entry(leader, read_format, buf + size);
if (err < 0)
return err;
size += err;
list_for_each_entry(sub, &leader->sibling_list, list_entry) {
err = perf_counter_read_entry(counter, read_format,
buf + size);
if (err < 0)
return err;
size += err;
}
return size;
}
static int perf_counter_read_one(struct perf_counter *counter,
u64 read_format, char __user *buf)
{
u64 values[4];
int n = 0;
values[n++] = perf_counter_read_value(counter);
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
values[n++] = counter->total_time_enabled +
atomic64_read(&counter->child_total_time_enabled);
}
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
values[n++] = counter->total_time_running +
atomic64_read(&counter->child_total_time_running);
}
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_counter_id(counter);
if (copy_to_user(buf, values, n * sizeof(u64)))
return -EFAULT;
return n * sizeof(u64);
}
/*
* Read the performance counter - simple non blocking version for now
*/
static ssize_t
perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
{
u64 values[4];
int n;
u64 read_format = counter->attr.read_format;
int ret;
/*
* Return end-of-file for a read on a counter that is in
......@@ -1721,28 +1828,18 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
if (counter->state == PERF_COUNTER_STATE_ERROR)
return 0;
if (count < perf_counter_read_size(counter))
return -ENOSPC;
WARN_ON_ONCE(counter->ctx->parent_ctx);
mutex_lock(&counter->child_mutex);
values[0] = perf_counter_read_tree(counter);
n = 1;
if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
values[n++] = counter->total_time_enabled +
atomic64_read(&counter->child_total_time_enabled);
if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
values[n++] = counter->total_time_running +
atomic64_read(&counter->child_total_time_running);
if (counter->attr.read_format & PERF_FORMAT_ID)
values[n++] = primary_counter_id(counter);
if (read_format & PERF_FORMAT_GROUP)
ret = perf_counter_read_group(counter, read_format, buf);
else
ret = perf_counter_read_one(counter, read_format, buf);
mutex_unlock(&counter->child_mutex);
if (count < n * sizeof(u64))
return -EINVAL;
count = n * sizeof(u64);
if (copy_to_user(buf, values, count))
return -EFAULT;
return count;
return ret;
}
static ssize_t
......@@ -2631,6 +2728,79 @@ static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p)
return task_pid_nr_ns(p, counter->ns);
}
static void perf_output_read_one(struct perf_output_handle *handle,
struct perf_counter *counter)
{
u64 read_format = counter->attr.read_format;
u64 values[4];
int n = 0;
values[n++] = atomic64_read(&counter->count);
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
values[n++] = counter->total_time_enabled +
atomic64_read(&counter->child_total_time_enabled);
}
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
values[n++] = counter->total_time_running +
atomic64_read(&counter->child_total_time_running);
}
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_counter_id(counter);
perf_output_copy(handle, values, n * sizeof(u64));
}
/*
* XXX PERF_FORMAT_GROUP vs inherited counters seems difficult.
*/
static void perf_output_read_group(struct perf_output_handle *handle,
struct perf_counter *counter)
{
struct perf_counter *leader = counter->group_leader, *sub;
u64 read_format = counter->attr.read_format;
u64 values[5];
int n = 0;
values[n++] = 1 + leader->nr_siblings;
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
values[n++] = leader->total_time_enabled;
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
values[n++] = leader->total_time_running;
if (leader != counter)
leader->pmu->read(leader);
values[n++] = atomic64_read(&leader->count);
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_counter_id(leader);
perf_output_copy(handle, values, n * sizeof(u64));
list_for_each_entry(sub, &leader->sibling_list, list_entry) {
n = 0;
if (sub != counter)
sub->pmu->read(sub);
values[n++] = atomic64_read(&sub->count);
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_counter_id(sub);
perf_output_copy(handle, values, n * sizeof(u64));
}
}
static void perf_output_read(struct perf_output_handle *handle,
struct perf_counter *counter)
{
if (counter->attr.read_format & PERF_FORMAT_GROUP)
perf_output_read_group(handle, counter);
else
perf_output_read_one(handle, counter);
}
void perf_counter_output(struct perf_counter *counter, int nmi,
struct perf_sample_data *data)
{
......@@ -2642,10 +2812,6 @@ void perf_counter_output(struct perf_counter *counter, int nmi,
struct {
u32 pid, tid;
} tid_entry;
struct {
u64 id;
u64 counter;
} group_entry;
struct perf_callchain_entry *callchain = NULL;
int callchain_size = 0;
u64 time;
......@@ -2700,10 +2866,8 @@ void perf_counter_output(struct perf_counter *counter, int nmi,
if (sample_type & PERF_SAMPLE_PERIOD)
header.size += sizeof(u64);
if (sample_type & PERF_SAMPLE_GROUP) {
header.size += sizeof(u64) +
counter->nr_siblings * sizeof(group_entry);
}
if (sample_type & PERF_SAMPLE_READ)
header.size += perf_counter_read_size(counter);
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
callchain = perf_callchain(data->regs);
......@@ -2760,26 +2924,8 @@ void perf_counter_output(struct perf_counter *counter, int nmi,
if (sample_type & PERF_SAMPLE_PERIOD)
perf_output_put(&handle, data->period);
/*
* XXX PERF_SAMPLE_GROUP vs inherited counters seems difficult.
*/
if (sample_type & PERF_SAMPLE_GROUP) {
struct perf_counter *leader, *sub;
u64 nr = counter->nr_siblings;
perf_output_put(&handle, nr);
leader = counter->group_leader;
list_for_each_entry(sub, &leader->sibling_list, list_entry) {
if (sub != counter)
sub->pmu->read(sub);
group_entry.id = primary_counter_id(sub);
group_entry.counter = atomic64_read(&sub->count);
perf_output_put(&handle, group_entry);
}
}
if (sample_type & PERF_SAMPLE_READ)
perf_output_read(&handle, counter);
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
if (callchain)
......@@ -2818,8 +2964,6 @@ struct perf_read_event {
u32 pid;
u32 tid;
u64 value;
u64 format[3];
};
static void
......@@ -2831,34 +2975,20 @@ perf_counter_read_event(struct perf_counter *counter,
.header = {
.type = PERF_EVENT_READ,
.misc = 0,
.size = sizeof(event) - sizeof(event.format),
.size = sizeof(event) + perf_counter_read_size(counter),
},
.pid = perf_counter_pid(counter, task),
.tid = perf_counter_tid(counter, task),
.value = atomic64_read(&counter->count),
};
int ret, i = 0;
if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
event.header.size += sizeof(u64);
event.format[i++] = counter->total_time_enabled;
}
if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
event.header.size += sizeof(u64);
event.format[i++] = counter->total_time_running;
}
if (counter->attr.read_format & PERF_FORMAT_ID) {
event.header.size += sizeof(u64);
event.format[i++] = primary_counter_id(counter);
}
int ret;
ret = perf_output_begin(&handle, counter, event.header.size, 0, 0);
if (ret)
return;
perf_output_copy(&handle, &event, event.header.size);
perf_output_put(&handle, event);
perf_output_read(&handle, counter);
perf_output_end(&handle);
}
......@@ -3921,9 +4051,9 @@ perf_counter_alloc(struct perf_counter_attr *attr,
atomic64_set(&hwc->period_left, hwc->sample_period);
/*
* we currently do not support PERF_SAMPLE_GROUP on inherited counters
* we currently do not support PERF_FORMAT_GROUP on inherited counters
*/
if (attr->inherit && (attr->sample_type & PERF_SAMPLE_GROUP))
if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
goto done;
switch (attr->type) {
......
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