[GIT PULL] perfcounter fixes

From: Ingo Molnar
Date: Tue Aug 04 2009 - 15:18:54 EST

Linus,

Please pull the latest perfcounters-fixes-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git perfcounters-fixes-for-linus

Note, i was unsure about this commit:

f265426: perf_counter: Set the CONFIG_PERF_COUNTERS default to y if CONFIG_PROFILING=y

Is it proper to offer up a default-y if CONFIG_PROFILING is set to y
already and default-off otherwise?

I kept this the last commit so we can zap it easily if it's not ok.

Thanks,

Ingo

------------------>
Arnaldo Carvalho de Melo (1):
perf top: Add mwait_idle_with_hints to skip_symbols[]

Ingo Molnar (2):
perf_counter tools: Fix link errors with older toolchains
perf_counter: Set the CONFIG_PERF_COUNTERS default to y if CONFIG_PROFILING=y

Peter Zijlstra (4):
tracing, perf_counter: Add help text to CONFIG_EVENT_PROFILE
perf_counter: Collapse inherit on read()
perf_counter: Full task tracing
perf report: Update for the new FORK/EXIT events

Roel Kluin (1):
perf: Fix read buffer overflow

Stoyan Gaydarov (1):
perf tools: Fix faulty check


include/linux/perf_counter.h | 13 +++++-
init/Kconfig | 11 ++++-
kernel/fork.c | 4 +-
kernel/perf_counter.c | 101 +++++++++++++++++++++++++++++------------
tools/perf/Makefile | 2 +-
tools/perf/builtin-report.c | 24 ++++++++--
tools/perf/builtin-top.c | 1 +
tools/perf/util/quote.c | 2 +-
tools/perf/util/symbol.c | 2 +-
9 files changed, 117 insertions(+), 43 deletions(-)

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index bd15d7a..e604e6e 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -181,8 +181,9 @@ struct perf_counter_attr {
freq : 1, /* use freq, not period */
inherit_stat : 1, /* per task counts */
enable_on_exec : 1, /* next exec enables */
+ task : 1, /* trace fork/exit */

- __reserved_1 : 51;
+ __reserved_1 : 50;

__u32 wakeup_events; /* wakeup every n events */
__u32 __reserved_2;
@@ -311,6 +312,15 @@ enum perf_event_type {
/*
* struct {
* struct perf_event_header header;
+ * u32 pid, ppid;
+ * u32 tid, ptid;
+ * };
+ */
+ PERF_EVENT_EXIT = 4,
+
+ /*
+ * struct {
+ * struct perf_event_header header;
* u64 time;
* u64 id;
* u64 stream_id;
@@ -323,6 +333,7 @@ enum perf_event_type {
* struct {
* struct perf_event_header header;
* u32 pid, ppid;
+ * u32 tid, ptid;
* };
*/
PERF_EVENT_FORK = 7,
diff --git a/init/Kconfig b/init/Kconfig
index cb2c092..3f7e609 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -940,6 +940,7 @@ menu "Performance Counters"

config PERF_COUNTERS
bool "Kernel Performance Counters"
+ default y if PROFILING
depends on HAVE_PERF_COUNTERS
select ANON_INODES
help
@@ -961,9 +962,17 @@ config PERF_COUNTERS
Say Y if unsure.

config EVENT_PROFILE
- bool "Tracepoint profile sources"
+ bool "Tracepoint profiling sources"
depends on PERF_COUNTERS && EVENT_TRACING
default y
+ help
+ Allow the use of tracepoints as software performance counters.
+
+ When this is enabled, you can create perf counters based on
+ tracepoints using PERF_TYPE_TRACEPOINT and the tracepoint ID
+ found in debugfs://tracing/events/*/*/id. (The -e/--events
+ option to the perf tool can parse and interpret symbolic
+ tracepoints, in the subsystem:tracepoint_name format.)

endmenu

diff --git a/kernel/fork.c b/kernel/fork.c
index 29b532e..466531e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1269,6 +1269,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
write_unlock_irq(&tasklist_lock);
proc_fork_connector(p);
cgroup_post_fork(p);
+ perf_counter_fork(p);
return p;

bad_fork_free_pid:
@@ -1410,9 +1411,6 @@ long do_fork(unsigned long clone_flags,
init_completion(&vfork);
}

- if (!(clone_flags & CLONE_THREAD))
- perf_counter_fork(p);
-
audit_finish_fork(p);
tracehook_report_clone(regs, clone_flags, nr, p);

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 9509310..199ed47 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -42,6 +42,7 @@ static int perf_overcommit __read_mostly = 1;
static atomic_t nr_counters __read_mostly;
static atomic_t nr_mmap_counters __read_mostly;
static atomic_t nr_comm_counters __read_mostly;
+static atomic_t nr_task_counters __read_mostly;

/*
* perf counter paranoia level:
@@ -1654,6 +1655,8 @@ static void free_counter(struct perf_counter *counter)
atomic_dec(&nr_mmap_counters);
if (counter->attr.comm)
atomic_dec(&nr_comm_counters);
+ if (counter->attr.task)
+ atomic_dec(&nr_task_counters);
}

if (counter->destroy)
@@ -1688,6 +1691,18 @@ static int perf_release(struct inode *inode, struct file *file)
return 0;
}

+static u64 perf_counter_read_tree(struct perf_counter *counter)
+{
+ struct perf_counter *child;
+ u64 total = 0;
+
+ total += perf_counter_read(counter);
+ list_for_each_entry(child, &counter->child_list, child_list)
+ total += perf_counter_read(child);
+
+ return total;
+}
+
/*
* Read the performance counter - simple non blocking version for now
*/
@@ -1707,7 +1722,7 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)

WARN_ON_ONCE(counter->ctx->parent_ctx);
mutex_lock(&counter->child_mutex);
- values[0] = perf_counter_read(counter);
+ 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 +
@@ -2819,10 +2834,12 @@ perf_counter_read_event(struct perf_counter *counter,
}

/*
- * fork tracking
+ * task tracking -- fork/exit
+ *
+ * enabled by: attr.comm | attr.mmap | attr.task
*/

-struct perf_fork_event {
+struct perf_task_event {
struct task_struct *task;

struct {
@@ -2830,37 +2847,42 @@ struct perf_fork_event {

u32 pid;
u32 ppid;
+ u32 tid;
+ u32 ptid;
} event;
};

-static void perf_counter_fork_output(struct perf_counter *counter,
- struct perf_fork_event *fork_event)
+static void perf_counter_task_output(struct perf_counter *counter,
+ struct perf_task_event *task_event)
{
struct perf_output_handle handle;
- int size = fork_event->event.header.size;
- struct task_struct *task = fork_event->task;
+ int size = task_event->event.header.size;
+ struct task_struct *task = task_event->task;
int ret = perf_output_begin(&handle, counter, size, 0, 0);

if (ret)
return;

- fork_event->event.pid = perf_counter_pid(counter, task);
- fork_event->event.ppid = perf_counter_pid(counter, task->real_parent);
+ task_event->event.pid = perf_counter_pid(counter, task);
+ task_event->event.ppid = perf_counter_pid(counter, task->real_parent);

- perf_output_put(&handle, fork_event->event);
+ task_event->event.tid = perf_counter_tid(counter, task);
+ task_event->event.ptid = perf_counter_tid(counter, task->real_parent);
+
+ perf_output_put(&handle, task_event->event);
perf_output_end(&handle);
}

-static int perf_counter_fork_match(struct perf_counter *counter)
+static int perf_counter_task_match(struct perf_counter *counter)
{
- if (counter->attr.comm || counter->attr.mmap)
+ if (counter->attr.comm || counter->attr.mmap || counter->attr.task)
return 1;

return 0;
}

-static void perf_counter_fork_ctx(struct perf_counter_context *ctx,
- struct perf_fork_event *fork_event)
+static void perf_counter_task_ctx(struct perf_counter_context *ctx,
+ struct perf_task_event *task_event)
{
struct perf_counter *counter;

@@ -2869,19 +2891,19 @@ static void perf_counter_fork_ctx(struct perf_counter_context *ctx,

rcu_read_lock();
list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
- if (perf_counter_fork_match(counter))
- perf_counter_fork_output(counter, fork_event);
+ if (perf_counter_task_match(counter))
+ perf_counter_task_output(counter, task_event);
}
rcu_read_unlock();
}

-static void perf_counter_fork_event(struct perf_fork_event *fork_event)
+static void perf_counter_task_event(struct perf_task_event *task_event)
{
struct perf_cpu_context *cpuctx;
struct perf_counter_context *ctx;

cpuctx = &get_cpu_var(perf_cpu_context);
- perf_counter_fork_ctx(&cpuctx->ctx, fork_event);
+ perf_counter_task_ctx(&cpuctx->ctx, task_event);
put_cpu_var(perf_cpu_context);

rcu_read_lock();
@@ -2891,32 +2913,40 @@ static void perf_counter_fork_event(struct perf_fork_event *fork_event)
*/
ctx = rcu_dereference(current->perf_counter_ctxp);
if (ctx)
- perf_counter_fork_ctx(ctx, fork_event);
+ perf_counter_task_ctx(ctx, task_event);
rcu_read_unlock();
}

-void perf_counter_fork(struct task_struct *task)
+static void perf_counter_task(struct task_struct *task, int new)
{
- struct perf_fork_event fork_event;
+ struct perf_task_event task_event;

if (!atomic_read(&nr_comm_counters) &&
- !atomic_read(&nr_mmap_counters))
+ !atomic_read(&nr_mmap_counters) &&
+ !atomic_read(&nr_task_counters))
return;

- fork_event = (struct perf_fork_event){
+ task_event = (struct perf_task_event){
.task = task,
.event = {
.header = {
- .type = PERF_EVENT_FORK,
+ .type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
.misc = 0,
- .size = sizeof(fork_event.event),
+ .size = sizeof(task_event.event),
},
/* .pid */
/* .ppid */
+ /* .tid */
+ /* .ptid */
},
};

- perf_counter_fork_event(&fork_event);
+ perf_counter_task_event(&task_event);
+}
+
+void perf_counter_fork(struct task_struct *task)
+{
+ perf_counter_task(task, 1);
}

/*
@@ -3875,6 +3905,8 @@ done:
atomic_inc(&nr_mmap_counters);
if (counter->attr.comm)
atomic_inc(&nr_comm_counters);
+ if (counter->attr.task)
+ atomic_inc(&nr_task_counters);
}

return counter;
@@ -4236,8 +4268,10 @@ void perf_counter_exit_task(struct task_struct *child)
struct perf_counter_context *child_ctx;
unsigned long flags;

- if (likely(!child->perf_counter_ctxp))
+ if (likely(!child->perf_counter_ctxp)) {
+ perf_counter_task(child, 0);
return;
+ }

local_irq_save(flags);
/*
@@ -4255,15 +4289,22 @@ void perf_counter_exit_task(struct task_struct *child)
* incremented the context's refcount before we do put_ctx below.
*/
spin_lock(&child_ctx->lock);
- child->perf_counter_ctxp = NULL;
/*
* If this context is a clone; unclone it so it can't get
* swapped to another process while we're removing all
* the counters from it.
*/
unclone_ctx(child_ctx);
- spin_unlock(&child_ctx->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+ /*
+ * Report the task dead after unscheduling the counters so that we
+ * won't get any samples after PERF_EVENT_EXIT. We can however still
+ * get a few PERF_EVENT_READ events.
+ */
+ perf_counter_task(child, 0);
+
+ child->perf_counter_ctxp = NULL;

/*
* We can recurse on the same lock type through:
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index a5e9b87..4b20fa4 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -345,7 +345,7 @@ BUILTIN_OBJS += builtin-stat.o
BUILTIN_OBJS += builtin-top.o

PERFLIBS = $(LIB_FILE)
-EXTLIBS = -lbfd
+EXTLIBS = -lbfd -liberty

#
# Platform specific tweaks
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index b20a4b6..ce4f286 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -99,6 +99,7 @@ struct comm_event {
struct fork_event {
struct perf_event_header header;
u32 pid, ppid;
+ u32 tid, ptid;
};

struct lost_event {
@@ -252,7 +253,7 @@ static int strcommon(const char *pathname)
{
int n = 0;

- while (pathname[n] == cwd[n] && n < cwdlen)
+ while (n < cwdlen && pathname[n] == cwd[n])
++n;

return n;
@@ -1608,15 +1609,27 @@ process_comm_event(event_t *event, unsigned long offset, unsigned long head)
}

static int
-process_fork_event(event_t *event, unsigned long offset, unsigned long head)
+process_task_event(event_t *event, unsigned long offset, unsigned long head)
{
struct thread *thread = threads__findnew(event->fork.pid);
struct thread *parent = threads__findnew(event->fork.ppid);

- dprintf("%p [%p]: PERF_EVENT_FORK: %d:%d\n",
+ dprintf("%p [%p]: PERF_EVENT_%s: (%d:%d):(%d:%d)\n",
(void *)(offset + head),
(void *)(long)(event->header.size),
- event->fork.pid, event->fork.ppid);
+ event->header.type == PERF_EVENT_FORK ? "FORK" : "EXIT",
+ event->fork.pid, event->fork.tid,
+ event->fork.ppid, event->fork.ptid);
+
+ /*
+ * A thread clone will have the same PID for both
+ * parent and child.
+ */
+ if (thread == parent)
+ return 0;
+
+ if (event->header.type == PERF_EVENT_EXIT)
+ return 0;

if (!thread || !parent || thread__fork(thread, parent)) {
dprintf("problem processing PERF_EVENT_FORK, skipping event.\n");
@@ -1706,7 +1719,8 @@ process_event(event_t *event, unsigned long offset, unsigned long head)
return process_comm_event(event, offset, head);

case PERF_EVENT_FORK:
- return process_fork_event(event, offset, head);
+ case PERF_EVENT_EXIT:
+ return process_task_event(event, offset, head);

case PERF_EVENT_LOST:
return process_lost_event(event, offset, head);
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index c0a4230..f139f1a 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -285,6 +285,7 @@ static const char *skip_symbols[] = {
"enter_idle",
"exit_idle",
"mwait_idle",
+ "mwait_idle_with_hints",
"ppc64_runlatch_off",
"pseries_dedicated_idle_sleep",
NULL
diff --git a/tools/perf/util/quote.c b/tools/perf/util/quote.c
index c6e5dc0..2726fe4 100644
--- a/tools/perf/util/quote.c
+++ b/tools/perf/util/quote.c
@@ -318,7 +318,7 @@ char *quote_path_relative(const char *in, int len,
strbuf_addch(out, '"');
if (prefix) {
int off = 0;
- while (prefix[off] && off < len && prefix[off] == in[off])
+ while (off < len && prefix[off] && prefix[off] == in[off])
if (prefix[off] == '/') {
prefix += off + 1;
in += off + 1;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 2810605..b4fe057 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -565,7 +565,7 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
goto out_elf_end;

secstrs = elf_getdata(sec_strndx, NULL);
- if (symstrs == NULL)
+ if (secstrs == NULL)
goto out_elf_end;

nr_syms = shdr.sh_size / shdr.sh_entsize;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/