Add a thread stack for synthesizing call chains from call
and return events.
Signed-off-by: Adrian Hunter <adrian.hun...@intel.com>
---
tools/perf/Makefile.perf | 2 +
tools/perf/util/event.h | 26 +++++++
tools/perf/util/thread-stack.c | 172 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/thread-stack.h | 32 ++++++++
tools/perf/util/thread.c | 3 +
tools/perf/util/thread.h | 3 +
6 files changed, 238 insertions(+)
create mode 100644 tools/perf/util/thread-stack.c
create mode 100644 tools/perf/util/thread-stack.h
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 3caf7da..0ebcc4a 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -317,6 +317,7 @@ LIB_H += ui/util.h
LIB_H += ui/ui.h
LIB_H += util/data.h
LIB_H += util/kvm-stat.h
+LIB_H += util/thread-stack.h
LIB_OBJS += $(OUTPUT)util/abspath.o
LIB_OBJS += $(OUTPUT)util/alias.o
@@ -394,6 +395,7 @@ LIB_OBJS += $(OUTPUT)util/srcline.o
LIB_OBJS += $(OUTPUT)util/data.o
LIB_OBJS += $(OUTPUT)util/tsc.o
LIB_OBJS += $(OUTPUT)util/cloexec.o
+LIB_OBJS += $(OUTPUT)util/thread-stack.o
LIB_OBJS += $(OUTPUT)ui/setup.o
LIB_OBJS += $(OUTPUT)ui/helpline.o
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 8c7fe9d..7be3897 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -143,6 +143,32 @@ struct branch_stack {
struct branch_entry entries[0];
};
+enum {
+ PERF_IP_FLAG_BRANCH = 1ULL << 0,
+ PERF_IP_FLAG_CALL = 1ULL << 1,
+ PERF_IP_FLAG_RETURN = 1ULL << 2,
+ PERF_IP_FLAG_CONDITIONAL = 1ULL << 3,
+ PERF_IP_FLAG_SYSCALLRET = 1ULL << 4,
+ PERF_IP_FLAG_ASYNC = 1ULL << 5,
+ PERF_IP_FLAG_INTERRUPT = 1ULL << 6,
+ PERF_IP_FLAG_TX_ABORT = 1ULL << 7,
+ PERF_IP_FLAG_TRACE_BEGIN = 1ULL << 8,
+ PERF_IP_FLAG_TRACE_END = 1ULL << 9,
+ PERF_IP_FLAG_IN_TX = 1ULL << 10,
+};
+
+#define PERF_BRANCH_MASK (\
+ PERF_IP_FLAG_BRANCH |\
+ PERF_IP_FLAG_CALL |\
+ PERF_IP_FLAG_RETURN |\
+ PERF_IP_FLAG_CONDITIONAL |\
+ PERF_IP_FLAG_SYSCALLRET |\
+ PERF_IP_FLAG_ASYNC |\
+ PERF_IP_FLAG_INTERRUPT |\
+ PERF_IP_FLAG_TX_ABORT |\
+ PERF_IP_FLAG_TRACE_BEGIN |\
+ PERF_IP_FLAG_TRACE_END)
+
struct perf_sample {
u64 ip;
u32 pid, tid;
diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
new file mode 100644
index 0000000..85b60d2
--- /dev/null
+++ b/tools/perf/util/thread-stack.c
@@ -0,0 +1,172 @@
+/*
+ * thread-stack.c: Synthesize a thread's stack using call / return events
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include "thread.h"
+#include "event.h"
+#include "util.h"
+#include "debug.h"
+#include "thread-stack.h"
+
+#define STACK_GROWTH 4096
+
+struct thread_stack_entry {
+ u64 ret_addr;
+};
+
+struct thread_stack {
+ struct thread_stack_entry *stack;
+ size_t cnt;
+ size_t sz;
+ u64 trace_nr;
+};
+
+static int thread_stack__grow(struct thread_stack *ts)
+{
+ struct thread_stack_entry *new_stack;
+ size_t sz, new_sz;
+
+ new_sz = ts->sz + STACK_GROWTH;
+ sz = new_sz * sizeof(struct thread_stack_entry);
+
+ new_stack = realloc(ts->stack, sz);
+ if (!new_stack)
+ return -ENOMEM;
+
+ ts->stack = new_stack;
+ ts->sz = new_sz;
+
+ return 0;
+}
+
+static struct thread_stack *thread_stack__new(void)
+{
+ struct thread_stack *ts;
+
+ ts = zalloc(sizeof(struct thread_stack));
+ if (!ts)
+ return NULL;
+
+ if (thread_stack__grow(ts)) {
+ free(ts);
+ return NULL;
+ }
+
+ return ts;
+}
+
+static int thread_stack__push(struct thread_stack *ts, u64 ret_addr)
+{
+ int err = 0;
+
+ if (ts->cnt == ts->sz) {
+ err = thread_stack__grow(ts);
+ if (err) {
+ pr_warning("Out of memory: discarding thread stack\n");
+ ts->cnt = 0;
+ }
+ }
+
+ ts->stack[ts->cnt++].ret_addr = ret_addr;
+
+ return err;
+}
+
+static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr)
+{
+ size_t i;
+
+ /*
+ * In some cases there may be functions which are not seen to return.
+ * For example when setjmp / longjmp has been used. Or the perf context
+ * switch in the kernel which doesn't stop and start tracing in exactly
+ * the same code path. When that happens the return address will be
+ * further down the stack. If the return address is not found at all,
+ * we assume the opposite (i.e. this is a return for a call that wasn't
+ * seen for some reason) and leave the stack alone.
+ */
+ for (i = ts->cnt; i; ) {
+ if (ts->stack[--i].ret_addr == ret_addr) {
+ ts->cnt = i;
+ return;
+ }
+ }
+}
+
+int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
+ u64 to_ip, u16 insn_len, u64 trace_nr)
+{
+ if (!thread)
+ return -EINVAL;
+
+ if (!thread->ts) {
+ thread->ts = thread_stack__new();
+ if (!thread->ts) {
+ pr_warning("Out of memory: no thread stack\n");
+ return -ENOMEM;
+ }
+ thread->ts->trace_nr = trace_nr;
+ }
+
+ /*
+ * When the trace is discontinuous, the trace_nr changes. In that case
+ * the stack might be completely invalid. Better to report nothing than
+ * to report something misleading, so reset the stack count to zero.
+ */
+ if (trace_nr != thread->ts->trace_nr) {
+ thread->ts->trace_nr = trace_nr;
+ thread->ts->cnt = 0;
+ }
+
+ if (flags & PERF_IP_FLAG_CALL) {
+ u64 ret_addr;
+
+ if (!to_ip)
+ return 0;
+ ret_addr = from_ip + insn_len;
+ if (ret_addr == to_ip)
+ return 0; /* Zero-length calls are excluded */
+ return thread_stack__push(thread->ts, ret_addr);
+ } else if (flags & PERF_IP_FLAG_RETURN) {
+ if (!from_ip)
+ return 0;
+ thread_stack__pop(thread->ts, to_ip);
+ }
+
+ return 0;
+}
+
+void thread_stack__free(struct thread *thread)
+{
+ if (thread->ts) {
+ zfree(&thread->ts->stack);
+ zfree(&thread->ts);
+ }
+}
+
+void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
+ size_t sz, u64 ip)
+{
+ size_t i;
+
+ if (!thread || !thread->ts)
+ chain->nr = 1;
+ else
+ chain->nr = min(sz, thread->ts->cnt + 1);
+
+ chain->ips[0] = ip;
+
+ for (i = 1; i < chain->nr; i++)
+ chain->ips[i] = thread->ts->stack[thread->ts->cnt - i].ret_addr;
+}
diff --git a/tools/perf/util/thread-stack.h b/tools/perf/util/thread-stack.h
new file mode 100644
index 0000000..7c41579
--- /dev/null
+++ b/tools/perf/util/thread-stack.h
@@ -0,0 +1,32 @@
+/*
+ * thread-stack.h: Synthesize a thread's stack using call / return events
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#ifndef __PERF_THREAD_STACK_H
+#define __PERF_THREAD_STACK_H
+
+#include <sys/types.h>
+
+#include <linux/types.h>
+
+struct thread;
+struct ip_callchain;
+
+int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
+ u64 to_ip, u16 insn_len, u64 trace_nr);
+void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
+ size_t sz, u64 ip);
+void thread_stack__free(struct thread *thread);
+
+#endif
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index bf5bf85..a2157f0 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -4,6 +4,7 @@
#include <string.h>
#include "session.h"
#include "thread.h"
+#include "thread-stack.h"
#include "util.h"
#include "debug.h"
#include "comm.h"
@@ -66,6 +67,8 @@ void thread__delete(struct thread *thread)
{
struct comm *comm, *tmp;
+ thread_stack__free(thread);
+
if (thread->mg) {
map_groups__put(thread->mg);
thread->mg = NULL;
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index d34cf5c..160fd06 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -8,6 +8,8 @@
#include "symbol.h"
#include <strlist.h>
+struct thread_stack;
+
struct thread {
union {
struct rb_node rb_node;
@@ -26,6 +28,7 @@ struct thread {
u64 db_id;
void *priv;
+ struct thread_stack *ts;
};
struct machine;
--
1.9.1
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