On 31/10/18 4:15 PM, Adrian Hunter wrote:
> On 31/10/18 3:28 PM, Arnaldo Carvalho de Melo wrote:
>> Em Wed, Oct 31, 2018 at 11:10:42AM +0200, Adrian Hunter escreveu:
>>> In the absence of a fallback, callchains must encode also the callchain
>>> context. Do that now there is no fallback.
>>
>> So, this one is independent of the first 3 patches, right?
>
> Yes. I was just going to test it separately when I noticed I had
> screwed up my earlier testing. When I re-tested I discovered this patch
> has an off-by-one error:
>
> diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
> index afdf36852ac8..61a4286a74dc 100644
> --- a/tools/perf/util/thread-stack.c
> +++ b/tools/perf/util/thread-stack.c
> @@ -337,7 +337,7 @@ void thread_stack__sample(struct thread *thread, struct
> ip_callchain *chain,
>
> last_context = context;
>
> - for (i = 2, j = 0; i < sz && j < thread->ts->cnt; i++, j++) {
> + for (i = 2, j = 1; i < sz && j <= thread->ts->cnt; i++, j++) {
> ip = thread->ts->stack[thread->ts->cnt - j].ret_addr;
> context = callchain_context(ip, kernel_start);
> if (context != last_context) {
>
> Shall I send V2?
I have attached it
>From 19a9fbdbd3729c7f14c9c1f0ac79c18cce91ff60 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hun...@intel.com>
Date: Wed, 31 Oct 2018 09:31:25 +0200
Subject: [PATCH V2 4/5] perf intel-pt: Insert callchain context into
synthesized callchains
In the absence of a fallback, callchains must encode also the callchain
context. Do that now there is no fallback.
Signed-off-by: Adrian Hunter <adrian.hun...@intel.com>
Cc: sta...@vger.kernel.org # 4.19
---
Changes in V2:
Fix off-by-one error
tools/perf/util/intel-pt.c | 6 +++--
tools/perf/util/thread-stack.c | 44 +++++++++++++++++++++++++++-------
tools/perf/util/thread-stack.h | 2 +-
3 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index ffa385a029b3..60732213d16a 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -759,7 +759,8 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
if (pt->synth_opts.callchain) {
size_t sz = sizeof(struct ip_callchain);
- sz += pt->synth_opts.callchain_sz * sizeof(u64);
+ /* Add 1 to callchain_sz for callchain context */
+ sz += (pt->synth_opts.callchain_sz + 1) * sizeof(u64);
ptq->chain = zalloc(sz);
if (!ptq->chain)
goto out_free;
@@ -1160,7 +1161,8 @@ static void intel_pt_prep_sample(struct intel_pt *pt,
if (pt->synth_opts.callchain) {
thread_stack__sample(ptq->thread, ptq->chain,
- pt->synth_opts.callchain_sz, sample->ip);
+ pt->synth_opts.callchain_sz + 1,
+ sample->ip, pt->kernel_start);
sample->callchain = ptq->chain;
}
diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
index c091635bf7dc..61a4286a74dc 100644
--- a/tools/perf/util/thread-stack.c
+++ b/tools/perf/util/thread-stack.c
@@ -310,20 +310,46 @@ void thread_stack__free(struct thread *thread)
}
}
+static inline u64 callchain_context(u64 ip, u64 kernel_start)
+{
+ return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL;
+}
+
void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
- size_t sz, u64 ip)
+ size_t sz, u64 ip, u64 kernel_start)
{
- size_t i;
+ u64 context = callchain_context(ip, kernel_start);
+ u64 last_context;
+ size_t i, j;
- if (!thread || !thread->ts)
- chain->nr = 1;
- else
- chain->nr = min(sz, thread->ts->cnt + 1);
+ if (sz < 2) {
+ chain->nr = 0;
+ return;
+ }
- chain->ips[0] = ip;
+ chain->ips[0] = context;
+ chain->ips[1] = ip;
+
+ if (!thread || !thread->ts) {
+ chain->nr = 2;
+ return;
+ }
+
+ last_context = context;
+
+ for (i = 2, j = 1; i < sz && j <= thread->ts->cnt; i++, j++) {
+ ip = thread->ts->stack[thread->ts->cnt - j].ret_addr;
+ context = callchain_context(ip, kernel_start);
+ if (context != last_context) {
+ if (i >= sz - 1)
+ break;
+ chain->ips[i++] = context;
+ last_context = context;
+ }
+ chain->ips[i] = ip;
+ }
- for (i = 1; i < chain->nr; i++)
- chain->ips[i] = thread->ts->stack[thread->ts->cnt - i].ret_addr;
+ chain->nr = i;
}
struct call_return_processor *
diff --git a/tools/perf/util/thread-stack.h b/tools/perf/util/thread-stack.h
index b7e41c4ebfdd..f97c00a8c251 100644
--- a/tools/perf/util/thread-stack.h
+++ b/tools/perf/util/thread-stack.h
@@ -84,7 +84,7 @@ int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
u64 to_ip, u16 insn_len, u64 trace_nr);
void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr);
void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
- size_t sz, u64 ip);
+ size_t sz, u64 ip, u64 kernel_start);
int thread_stack__flush(struct thread *thread);
void thread_stack__free(struct thread *thread);
size_t thread_stack__depth(struct thread *thread);
--
2.17.1
