[v1,2/3] perf cs-etm: Add callchain to instruction sample
diff mbox series

Message ID 20190830062421.31275-3-leo.yan@linaro.org
State New
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Series
  • perf cs-etm: Add support for callchain
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Commit Message

Leo Yan Aug. 30, 2019, 6:24 a.m. UTC
Firstly, this patch adds support for the thread stack; when every branch
packet is coming we will push or pop the stack based on the sample
flags.

Secondly, based on the thread stack we can synthesize call chain for the
instruction sample, this can be used by itrace option '--itrace=g'.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 tools/perf/util/cs-etm.c | 74 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 1 deletion(-)

Comments

Mathieu Poirier Sept. 3, 2019, 10:07 p.m. UTC | #1
On Fri, Aug 30, 2019 at 02:24:20PM +0800, Leo Yan wrote:
> Firstly, this patch adds support for the thread stack; when every branch
> packet is coming we will push or pop the stack based on the sample
> flags.
> 
> Secondly, based on the thread stack we can synthesize call chain for the
> instruction sample, this can be used by itrace option '--itrace=g'.
>

In most cases using the word "secondly" is a good indication the patch should be
split.
 
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
>  tools/perf/util/cs-etm.c | 74 +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 73 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index 882a0718033d..ad573d3bd305 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -17,6 +17,7 @@
>  #include <stdlib.h>
>  
>  #include "auxtrace.h"
> +#include "callchain.h"
>  #include "color.h"
>  #include "cs-etm.h"
>  #include "cs-etm-decoder/cs-etm-decoder.h"
> @@ -69,6 +70,7 @@ struct cs_etm_traceid_queue {
>  	size_t last_branch_pos;
>  	union perf_event *event_buf;
>  	struct thread *thread;
> +	struct ip_callchain *chain;
>  	struct branch_stack *last_branch;
>  	struct branch_stack *last_branch_rb;
>  	struct cs_etm_packet *prev_packet;
> @@ -246,6 +248,16 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq,
>  	if (!tidq->prev_packet)
>  		goto out_free;
>  
> +	if (etm->synth_opts.callchain) {
> +		size_t sz = sizeof(struct ip_callchain);
> +
> +		/* Add 1 to callchain_sz for callchain context */
> +		sz += (etm->synth_opts.callchain_sz + 1) * sizeof(u64);
> +		tidq->chain = zalloc(sz);
> +		if (!tidq->chain)
> +			goto out_free;
> +	}
> +
>  	if (etm->synth_opts.last_branch) {
>  		size_t sz = sizeof(struct branch_stack);
>  
> @@ -270,6 +282,7 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq,
>  	zfree(&tidq->last_branch);
>  	zfree(&tidq->prev_packet);
>  	zfree(&tidq->packet);
> +	zfree(&tidq->chain);
>  out:
>  	return rc;
>  }
> @@ -541,6 +554,7 @@ static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq)
>  		zfree(&tidq->last_branch_rb);
>  		zfree(&tidq->prev_packet);
>  		zfree(&tidq->packet);
> +		zfree(&tidq->chain);
>  		zfree(&tidq);
>  
>  		/*
> @@ -1121,6 +1135,41 @@ static void cs_etm__copy_insn(struct cs_etm_queue *etmq,
>  			   sample->insn_len, (void *)sample->insn);
>  }
>  
> +static void cs_etm__add_stack_event(struct cs_etm_queue *etmq,
> +				    struct cs_etm_traceid_queue *tidq)
> +{
> +	struct cs_etm_auxtrace *etm = etmq->etm;
> +	u8 trace_chan_id = tidq->trace_chan_id;
> +	int insn_len;
> +	u64 from_ip, to_ip;
> +
> +	if (etm->synth_opts.callchain || etm->synth_opts.thread_stack) {
> +
> +		from_ip = cs_etm__last_executed_instr(tidq->prev_packet);
> +		to_ip = cs_etm__first_executed_instr(tidq->packet);
> +
> +		/*
> +		 * T32 instruction size might be 32-bit or 16-bit, decide by
> +		 * calling cs_etm__t32_instr_size().
> +		 */
> +		if (tidq->prev_packet->isa == CS_ETM_ISA_T32)
> +			insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id,
> +							  from_ip);
> +		/* Otherwise, A64 and A32 instruction size are always 32-bit. */
> +		else
> +			insn_len = 4;
> +
> +		thread_stack__event(tidq->thread, tidq->prev_packet->cpu,
> +				    tidq->prev_packet->flags,
> +				    from_ip, to_ip, insn_len,
> +				    etmq->buffer->buffer_nr);
> +	} else {
> +		thread_stack__set_trace_nr(tidq->thread,
> +					   tidq->prev_packet->cpu,
> +					   etmq->buffer->buffer_nr);

Please add a comment on what the above does.  As a rule of thumb I add a comment
per addition in a patch in order to help people understand what is happening and
some of the reasonning behing the code.

> +	}
> +}
> +
>  static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
>  					    struct cs_etm_traceid_queue *tidq,
>  					    u64 addr, u64 period)
> @@ -1146,6 +1195,14 @@ static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
>  
>  	cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->packet, &sample);
>  
> +	if (etm->synth_opts.callchain) {
> +		thread_stack__sample(tidq->thread, tidq->packet->cpu,
> +				     tidq->chain,
> +				     etm->synth_opts.callchain_sz + 1,
> +				     sample.ip, etm->kernel_start);
> +		sample.callchain = tidq->chain;
> +	}
> +
>  	if (etm->synth_opts.last_branch) {
>  		cs_etm__copy_last_branch_rb(etmq, tidq);
>  		sample.branch_stack = tidq->last_branch;
> @@ -1329,6 +1386,8 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm,
>  		attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR;
>  	}
>  
> +	if (etm->synth_opts.callchain)
> +		attr.sample_type |= PERF_SAMPLE_CALLCHAIN;
>  	if (etm->synth_opts.last_branch)
>  		attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
>  
> @@ -1397,6 +1456,9 @@ static int cs_etm__sample(struct cs_etm_queue *etmq,
>  		tidq->period_instructions = instrs_over;
>  	}
>  
> +	if (tidq->prev_packet->last_instr_taken_branch)
> +		cs_etm__add_stack_event(etmq, tidq);
> +
>  	if (etm->sample_branches) {
>  		bool generate_sample = false;
>  
> @@ -2596,7 +2658,17 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
>  	} else {
>  		itrace_synth_opts__set_default(&etm->synth_opts,
>  				session->itrace_synth_opts->default_no_sample);
> -		etm->synth_opts.callchain = false;
> +
> +		etm->synth_opts.thread_stack =
> +				session->itrace_synth_opts->thread_stack;
> +	}
> +
> +	if (etm->synth_opts.callchain && !symbol_conf.use_callchain) {
> +		symbol_conf.use_callchain = true;
> +		if (callchain_register_param(&callchain_param) < 0) {
> +			symbol_conf.use_callchain = false;
> +			etm->synth_opts.callchain = false;
> +		}
>  	}
>  
>  	err = cs_etm__synth_events(etm, session);
> -- 
> 2.17.1
>

Patch
diff mbox series

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 882a0718033d..ad573d3bd305 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -17,6 +17,7 @@ 
 #include <stdlib.h>
 
 #include "auxtrace.h"
+#include "callchain.h"
 #include "color.h"
 #include "cs-etm.h"
 #include "cs-etm-decoder/cs-etm-decoder.h"
@@ -69,6 +70,7 @@  struct cs_etm_traceid_queue {
 	size_t last_branch_pos;
 	union perf_event *event_buf;
 	struct thread *thread;
+	struct ip_callchain *chain;
 	struct branch_stack *last_branch;
 	struct branch_stack *last_branch_rb;
 	struct cs_etm_packet *prev_packet;
@@ -246,6 +248,16 @@  static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq,
 	if (!tidq->prev_packet)
 		goto out_free;
 
+	if (etm->synth_opts.callchain) {
+		size_t sz = sizeof(struct ip_callchain);
+
+		/* Add 1 to callchain_sz for callchain context */
+		sz += (etm->synth_opts.callchain_sz + 1) * sizeof(u64);
+		tidq->chain = zalloc(sz);
+		if (!tidq->chain)
+			goto out_free;
+	}
+
 	if (etm->synth_opts.last_branch) {
 		size_t sz = sizeof(struct branch_stack);
 
@@ -270,6 +282,7 @@  static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq,
 	zfree(&tidq->last_branch);
 	zfree(&tidq->prev_packet);
 	zfree(&tidq->packet);
+	zfree(&tidq->chain);
 out:
 	return rc;
 }
@@ -541,6 +554,7 @@  static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq)
 		zfree(&tidq->last_branch_rb);
 		zfree(&tidq->prev_packet);
 		zfree(&tidq->packet);
+		zfree(&tidq->chain);
 		zfree(&tidq);
 
 		/*
@@ -1121,6 +1135,41 @@  static void cs_etm__copy_insn(struct cs_etm_queue *etmq,
 			   sample->insn_len, (void *)sample->insn);
 }
 
+static void cs_etm__add_stack_event(struct cs_etm_queue *etmq,
+				    struct cs_etm_traceid_queue *tidq)
+{
+	struct cs_etm_auxtrace *etm = etmq->etm;
+	u8 trace_chan_id = tidq->trace_chan_id;
+	int insn_len;
+	u64 from_ip, to_ip;
+
+	if (etm->synth_opts.callchain || etm->synth_opts.thread_stack) {
+
+		from_ip = cs_etm__last_executed_instr(tidq->prev_packet);
+		to_ip = cs_etm__first_executed_instr(tidq->packet);
+
+		/*
+		 * T32 instruction size might be 32-bit or 16-bit, decide by
+		 * calling cs_etm__t32_instr_size().
+		 */
+		if (tidq->prev_packet->isa == CS_ETM_ISA_T32)
+			insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id,
+							  from_ip);
+		/* Otherwise, A64 and A32 instruction size are always 32-bit. */
+		else
+			insn_len = 4;
+
+		thread_stack__event(tidq->thread, tidq->prev_packet->cpu,
+				    tidq->prev_packet->flags,
+				    from_ip, to_ip, insn_len,
+				    etmq->buffer->buffer_nr);
+	} else {
+		thread_stack__set_trace_nr(tidq->thread,
+					   tidq->prev_packet->cpu,
+					   etmq->buffer->buffer_nr);
+	}
+}
+
 static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
 					    struct cs_etm_traceid_queue *tidq,
 					    u64 addr, u64 period)
@@ -1146,6 +1195,14 @@  static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
 
 	cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->packet, &sample);
 
+	if (etm->synth_opts.callchain) {
+		thread_stack__sample(tidq->thread, tidq->packet->cpu,
+				     tidq->chain,
+				     etm->synth_opts.callchain_sz + 1,
+				     sample.ip, etm->kernel_start);
+		sample.callchain = tidq->chain;
+	}
+
 	if (etm->synth_opts.last_branch) {
 		cs_etm__copy_last_branch_rb(etmq, tidq);
 		sample.branch_stack = tidq->last_branch;
@@ -1329,6 +1386,8 @@  static int cs_etm__synth_events(struct cs_etm_auxtrace *etm,
 		attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR;
 	}
 
+	if (etm->synth_opts.callchain)
+		attr.sample_type |= PERF_SAMPLE_CALLCHAIN;
 	if (etm->synth_opts.last_branch)
 		attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
 
@@ -1397,6 +1456,9 @@  static int cs_etm__sample(struct cs_etm_queue *etmq,
 		tidq->period_instructions = instrs_over;
 	}
 
+	if (tidq->prev_packet->last_instr_taken_branch)
+		cs_etm__add_stack_event(etmq, tidq);
+
 	if (etm->sample_branches) {
 		bool generate_sample = false;
 
@@ -2596,7 +2658,17 @@  int cs_etm__process_auxtrace_info(union perf_event *event,
 	} else {
 		itrace_synth_opts__set_default(&etm->synth_opts,
 				session->itrace_synth_opts->default_no_sample);
-		etm->synth_opts.callchain = false;
+
+		etm->synth_opts.thread_stack =
+				session->itrace_synth_opts->thread_stack;
+	}
+
+	if (etm->synth_opts.callchain && !symbol_conf.use_callchain) {
+		symbol_conf.use_callchain = true;
+		if (callchain_register_param(&callchain_param) < 0) {
+			symbol_conf.use_callchain = false;
+			etm->synth_opts.callchain = false;
+		}
 	}
 
 	err = cs_etm__synth_events(etm, session);