Re: [PATCH] perf: add /proc/perf_events file for dump perf events info
From: Jovi Zhang
Date: Thu Jul 05 2012 - 09:02:06 EST
On Thu, Jul 5, 2012 at 4:40 PM, Jovi Zhang <bookjovi@xxxxxxxxx> wrote:
>
>
>
> On Thu, Jul 5, 2012 at 4:27 PM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>>
>> On Thu, 2012-07-05 at 16:23 +0800, Jovi Zhang wrote:
>> > This new /proc/perf_events file is used for real time dump all
>> > perf events info in whole system wide machine, this patch also add
>> > a new field perf_entry in struct perf_event, for connect to
>> > global list perf_events_list.
>>
>> This fails to mention why you'd want something like that.
>
>
> Watch all perf events in system wide can be very useful for perf subsystem issue handling,
> to know which perf event is active in system,
> perf event is a resouce, it would like to be managed easily for user, with more visable, like /proc/timer, etc...
>
> .jovi
Ping...
Sorry that initial patch format corrupted because gmail client problem.
below patch with more readable format.
From 91fbcca37a2c9979083f4b9a6fa9c1875fc2886f Mon Sep 17 00:00:00 2001
From: Jovi Zhang <bookjovi@xxxxxxxxx>
Date: Fri, 6 Jul 2012 00:05:40 +0800
Subject: [PATCH] perf: add /proc/perf_events file for dump perf events info
This new /proc/perf_events file is used for real time dump all
perf events info in whole system wide machine, this patch also add
a new field perf_entry in struct perf_event, for connect to
global list perf_events_list.
$./perf record -e mem:0xc09b7020 -g -a -d
$cat /proc/perf_events
1:
pmu: tracepoint
state: ACTIVE
attach_state: ATTACH_CONTEXT ATTACH_GROUP
oncpu: 0
cpu: 0
count: 71
id: 18
attr.type: TRACEPOINT
attr.config: 927
attr.sample_type: IP TID TIME CPU RAW
attr.bp_type: EMPTY
attr.bp_addr: 0x0
attr.bp_len: 0
attr flag: disabled(1) inherit(1) pinned(0) exclusive(0)
exclude_user(0) exclude_kernel(0) exclude_hv(0) exclude_idle(0)
mmap(1) comm(1) freq(0) inherit_stat(0) enable_on_exec(0) task(0)
watermark(0) precise_ip(0) mmap_data(0) sample_id_all(1)
exclude_host(0) exclude_guest(1)
2:
pmu: tracepoint
state: ACTIVE
attach_state: ATTACH_CONTEXT ATTACH_GROUP
oncpu: 1
cpu: 1
count: 178
id: 19
attr.type: TRACEPOINT
attr.config: 927
attr.sample_type: IP TID TIME CPU RAW
attr.bp_type: EMPTY
attr.bp_addr: 0x0
attr.bp_len: 0
attr flag: disabled(1) inherit(1) pinned(0) exclusive(0)
exclude_user(0) exclude_kernel(0) exclude_hv(0) exclude_idle(0)
mmap(1) comm(1) freq(0) inherit_stat(0) enable_on_exec(0) task(0)
watermark(0) precise_ip(0) mmap_data(0) sample_id_all(1)
exclude_host(0) exclude_guest(1)
...
Signed-off-by: Jovi Zhang <bookjovi@xxxxxxxxx>
---
include/linux/perf_event.h | 1 +
kernel/events/Makefile | 1 +
kernel/events/core.c | 14 +++
kernel/events/proc_perf_events.c | 204 ++++++++++++++++++++++++++++++++++++++
4 files changed, 220 insertions(+)
create mode 100644 kernel/events/proc_perf_events.c
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 45db49f..7129558 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -871,6 +871,7 @@ struct perf_event {
struct list_head group_entry;
struct list_head event_entry;
struct list_head sibling_list;
+ struct list_head perf_entry; /* used for connect with all perf_event*/
struct hlist_node hlist_entry;
int nr_siblings;
int group_flags;
diff --git a/kernel/events/Makefile b/kernel/events/Makefile
index 103f5d1..8b34070 100644
--- a/kernel/events/Makefile
+++ b/kernel/events/Makefile
@@ -6,4 +6,5 @@ obj-y := core.o ring_buffer.o callchain.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_UPROBES) += uprobes.o
+obj-$(CONFIG_PROC_FS) += proc_perf_events.o
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d7d71d6..55766d0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -147,6 +147,10 @@ static LIST_HEAD(pmus);
static DEFINE_MUTEX(pmus_lock);
static struct srcu_struct pmus_srcu;
+LIST_HEAD(perf_events_list);
+DEFINE_MUTEX(perf_events_lock);
+
+
/*
* perf event paranoia level:
* -1 - not paranoid at all
@@ -2897,6 +2901,10 @@ static void free_event(struct perf_event *event)
if (event->ctx)
put_ctx(event->ctx);
+ mutex_lock(&perf_events_lock);
+ list_del_rcu(&event->perf_entry);
+ mutex_unlock(&perf_events_lock);
+
call_rcu(&event->rcu_head, free_event_rcu);
}
@@ -5916,6 +5924,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
INIT_LIST_HEAD(&event->event_entry);
INIT_LIST_HEAD(&event->sibling_list);
INIT_LIST_HEAD(&event->rb_entry);
+ INIT_LIST_HEAD(&event->perf_entry);
init_waitqueue_head(&event->waitq);
init_irq_work(&event->pending, perf_pending_event);
@@ -6013,6 +6022,10 @@ done:
}
}
+ mutex_lock(&perf_events_lock);
+ list_add_tail_rcu(&event->perf_entry, &perf_events_list);
+ mutex_unlock(&perf_events_lock);
+
return event;
}
@@ -7220,3 +7233,4 @@ struct cgroup_subsys perf_subsys = {
.attach = perf_cgroup_attach,
};
#endif /* CONFIG_CGROUP_PERF */
+
diff --git a/kernel/events/proc_perf_events.c b/kernel/events/proc_perf_events.c
new file mode 100644
index 0000000..5c2d56c
--- /dev/null
+++ b/kernel/events/proc_perf_events.c
@@ -0,0 +1,204 @@
+/*
+ * linux/kerenl/events/proc_perf_events.c
+ *
+ * Dump information for all perf_event
+ *
+ * Created by: Jovi Zhang (bookjovi@xxxxxxxxx)
+ *
+ */
+
+#include <linux/perf_event.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+extern struct list_head perf_events_list;
+extern struct mutex perf_events_lock;
+
+static const char *perf_state_name(enum perf_event_active_state state)
+{
+ const char *name;
+
+ switch (state) {
+ case PERF_EVENT_STATE_ERROR:
+ name = "ERROR";
+ break;
+ case PERF_EVENT_STATE_OFF:
+ name = "OFF";
+ break;
+ case PERF_EVENT_STATE_INACTIVE:
+ name = "INACTIVE";
+ break;
+ case PERF_EVENT_STATE_ACTIVE:
+ name = "ACTIVE";
+ break;
+ default:
+ name = "NULL";
+ }
+
+ return name;
+}
+
+static void perf_attach_state_show(struct seq_file *m,
+ unsigned int attach_state)
+{
+ seq_printf(m, "attach_state:\t\t");
+
+ if (attach_state & PERF_ATTACH_CONTEXT)
+ seq_printf(m, "ATTACH_CONTEXT ");
+ if (attach_state & PERF_ATTACH_GROUP)
+ seq_printf(m, "ATTACH_GROUP ");
+ if (attach_state & PERF_ATTACH_TASK)
+ seq_printf(m, " ATTACH_TASK ");
+
+ seq_putc(m, '\n');
+}
+
+static void perf_attr_sample_type_show(struct seq_file *m, __u64 sample_type)
+{
+ int i, valid = 0;
+
+ static char *sample_type_name[] = {
+ "IP",
+ "TID",
+ "TIME",
+ "ADDR",
+ "READ",
+ "CALLCHAIN",
+ "ID",
+ "CPU",
+ "PERIOD",
+ "STREAM_ID",
+ "RAW",
+ "BRANCH_STACK"
+ };
+
+ seq_printf(m, "attr.sample_type:\t");
+
+ for (i = 0; i < ARRAY_SIZE(sample_type_name); i++) {
+ if (sample_type & (1UL << i)) {
+ seq_printf(m, "%s ", sample_type_name[i]);
+ valid = 1;
+ }
+ }
+
+ if (!valid)
+ seq_printf(m, "NULL");
+
+ seq_putc(m, '\n');
+}
+
+static void perf_event_bp_show(struct seq_file *m,
+ __u32 bp_type, __u32 bp_addr, __u32 bp_len)
+{
+ char *name;
+
+ seq_printf(m, "attr.bp_type:\t\t");
+ switch (bp_type) {
+ case HW_BREAKPOINT_EMPTY:
+ name = "EMPTY";
+ break;
+ case HW_BREAKPOINT_R:
+ name = "R";
+ break;
+ case HW_BREAKPOINT_W:
+ name = "W";
+ break;
+ case HW_BREAKPOINT_RW:
+ name = "RW";
+ break;
+ case HW_BREAKPOINT_X:
+ name = "X";
+ break;
+ case HW_BREAKPOINT_INVALID:
+ name = "INVALID";
+ break;
+ default:
+ name = "NULL";
+ }
+ seq_printf(m, "%s\n", name);
+
+ seq_printf(m, "attr.bp_addr:\t\t0x%x\n", bp_addr);
+ seq_printf(m, "attr.bp_len:\t\t%d\n", bp_len);
+}
+
+static void perf_event_attr_show(struct seq_file *m,
+ struct perf_event_attr *attr)
+{
+ static const char * const type_name[] = {
+ "HARDWARE",
+ "SOFTWARE",
+ "TRACEPOINT",
+ "HW_CACHE",
+ "RAW",
+ "BREAKPOINT"
+ };
+
+ seq_printf(m, "attr.type:\t\t%s\n", type_name[attr->type]);
+ seq_printf(m, "attr.config:\t\t%llu\n", attr->config);
+ perf_attr_sample_type_show(m, attr->sample_type);
+ perf_event_bp_show(m, attr->bp_type, attr->bp_addr, attr->bp_len);
+ seq_printf(m, "attr flag:\t\tdisabled(%d) inherit(%d) pinned(%d) "
+ "exclusive(%d) exclude_user(%d) exclude_kernel(%d) "
+ "exclude_hv(%d) exclude_idle(%d) mmap(%d) comm(%d) "
+ "freq(%d) inherit_stat(%d) enable_on_exec(%d) task(%d) "
+ "watermark(%d) precise_ip(%d) mmap_data(%d) "
+ "sample_id_all(%d) exclude_host(%d) exclude_guest(%d)",
+ attr->disabled, attr->inherit, attr->pinned,
+ attr->exclusive, attr->exclude_user,
+ attr->exclude_kernel, attr->exclude_hv,
+ attr->exclude_idle, attr->mmap, attr->comm, attr->freq,
+ attr->inherit_stat, attr->enable_on_exec, attr->task,
+ attr->watermark, attr->precise_ip, attr->mmap_data,
+ attr->sample_id_all, attr->exclude_host,
+ attr->exclude_guest);
+ seq_putc(m, '\n');
+}
+
+static int perf_events_proc_show(struct seq_file *m, void *v)
+{
+ struct perf_event *event;
+ int i = 0;
+
+ mutex_lock(&perf_events_lock);
+ list_for_each_entry(event, &perf_events_list, perf_entry) {
+ i++;
+ seq_printf(m, "%d:\n", i);
+ seq_printf(m, "pmu:\t\t\t%s\n",
+ event->pmu ? event->pmu->name : "NULL");
+ seq_printf(m, "state:\t\t\t%s\n",
+ perf_state_name(event->state));
+ perf_attach_state_show(m, event->attach_state);
+ seq_printf(m, "oncpu:\t\t\t%d\n", event->oncpu);
+ seq_printf(m, "cpu:\t\t\t%d\n", event->cpu);
+ seq_printf(m, "count:\t\t\t%llu\n",
+ local64_read(&event->count));
+ seq_printf(m, "id:\t\t\t%llu\n", event->id);
+ perf_event_attr_show(m, &event->attr);
+
+ seq_putc(m, '\n');
+ }
+ mutex_unlock(&perf_events_lock);
+
+ return 0;
+}
+
+static int perf_events_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, perf_events_proc_show, NULL);
+}
+
+static const struct file_operations perf_events_proc_fops = {
+ .open = perf_events_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init proc_perf_events_init(void)
+{
+ proc_create("perf_events", 0444, NULL, &perf_events_proc_fops);
+ return 0;
+}
+
+device_initcall(proc_perf_events_init);
--
1.7.9.7
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