From: Leo Yan leo.yan@linaro.org
CS ETM already records branches into the thread stack, but instruction samples do not carry synthesized callchains. It misses to support the callchain and no output with the itrace option 'g'.
Allocate a callchain buffer per queue and use thread_stack__sample() when synthesizing instruction samples.
Advertise PERF_SAMPLE_CALLCHAIN on the synthetic instruction event. Allocate one extra callchain entry than requested, as the first entry is reserved for storing context information.
cs_etm__context() is introduced for handling context packet and update the thread info and start kernel address for frontend decoding.
After:
perf script --itrace=g16l64i1i
callchain_test 6543 [002] 1 instructions: ffff800080010c14 vectors+0x414 ([kernel.kallsyms]) aaaad6b60784 do_svc+0x1c (/home/kernel/leoy/test_cs_callchain/callchain_test) aaaad6b60798 print+0xc (/home/kernel/leoy/test_cs_callchain/callchain_test) aaaad6b607b0 foo+0xc (/home/kernel/leoy/test_cs_callchain/callchain_test) aaaad6b607c8 main+0xc (/home/kernel/leoy/test_cs_callchain/callchain_test) ffff9325225c __libc_start_call_main+0x7c (/usr/lib/aarch64-linux-gnu/libc.so.6) ffff9325233c call_init+0x9c (inlined) ffff9325233c __libc_start_main_impl+0x9c (inlined) aaaad6b60670 _start+0x30 (/home/kernel/leoy/test_cs_callchain/callchain_test) ffff800080012290 ret_to_user+0x120 ([kernel.kallsyms])
Signed-off-by: Leo Yan leo.yan@linaro.org Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com --- tools/perf/util/cs-etm.c | 83 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 78 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 30536b919af732abeee11d4f7813dcef0b4047eb..67885ed43bab9cfd47bdb30c598c4e36d0e191fb 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -18,6 +18,7 @@ #include <stdlib.h>
#include "auxtrace.h" +#include "callchain.h" #include "color.h" #include "cs-etm.h" #include "cs-etm-decoder/cs-etm-decoder.h" @@ -87,9 +88,11 @@ struct cs_etm_auxtrace { struct cs_etm_traceid_queue { u8 trace_chan_id; u64 period_instructions; + u64 kernel_start; union perf_event *event_buf; unsigned int br_stack_sz; struct branch_stack *last_branch; + struct ip_callchain *callchain; struct cs_etm_packet *prev_packet; struct cs_etm_packet *packet; struct cs_etm_packet_queue packet_queue; @@ -652,6 +655,15 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq, tidq->br_stack_sz = etm->synth_opts.last_branch_sz; }
+ if (etm->synth_opts.callchain) { + /* Add 1 to callchain_sz for callchain context */ + tidq->callchain = + zalloc(struct_size(tidq->callchain, ips, + etm->synth_opts.callchain_sz + 1)); + if (!tidq->callchain) + goto out_free; + } + tidq->event_buf = malloc(PERF_SAMPLE_MAX_SIZE); if (!tidq->event_buf) goto out_free; @@ -659,6 +671,7 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq, return 0;
out_free: + zfree(&tidq->callchain); zfree(&tidq->last_branch); zfree(&tidq->prev_packet); zfree(&tidq->packet); @@ -942,6 +955,7 @@ static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq) thread__zput(tidq->frontend_thread); thread__zput(tidq->decode_thread); zfree(&tidq->event_buf); + zfree(&tidq->callchain); zfree(&tidq->last_branch); zfree(&tidq->prev_packet); zfree(&tidq->packet); @@ -1584,6 +1598,26 @@ static void cs_etm__sample_branch_stack(struct cs_etm_auxtrace *etm, tidq->last_branch, tidq->br_stack_sz); sample->branch_stack = tidq->last_branch; } + + if (etm->synth_opts.callchain) { + if (tidq->kernel_start) + thread_stack__sample(tidq->frontend_thread, + tidq->packet->cpu, + tidq->callchain, + etm->synth_opts.callchain_sz + 1, + sample->ip, tidq->kernel_start); + else + /* + * Clear the callchain when the kernel start address is + * not available yet. The empty callchain can then be + * consumed by cs_etm__inject_event(). + */ + memset(tidq->callchain, 0, + struct_size(tidq->callchain, ips, + etm->synth_opts.callchain_sz + 1)); + + sample->callchain = tidq->callchain; + } }
static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq, @@ -1779,6 +1813,9 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm, attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX; }
+ if (etm->synth_opts.callchain) + attr.sample_type |= PERF_SAMPLE_CALLCHAIN; + if (etm->synth_opts.instructions) { attr.config = PERF_COUNT_HW_INSTRUCTIONS; attr.sample_period = etm->synth_opts.period; @@ -1910,6 +1947,34 @@ static int cs_etm__sample(struct cs_etm_queue *etmq, return 0; }
+static int cs_etm__context(struct cs_etm_queue *etmq, + struct cs_etm_traceid_queue *tidq) +{ + ocsd_ex_level el = tidq->packet->el; + struct machine *machine; + int ret; + + machine = cs_etm__get_machine(etmq, el); + if (!machine) { + ret = -EINVAL; + goto err; + } + + tidq->kernel_start = machine__kernel_start(machine); + + ret = cs_etm__etmq_update_thread(etmq, el, tidq->packet->tid, + &tidq->frontend_thread); + if (ret) + goto err; + + return 0; + +err: + thread__zput(tidq->frontend_thread); + tidq->kernel_start = 0; + return ret; +} + static int cs_etm__exception(struct cs_etm_traceid_queue *tidq) { /* @@ -2510,9 +2575,7 @@ static int cs_etm__process_traceid_queue(struct cs_etm_queue *etmq, * tracing the kernel the context packet will be emitted * between two ranges. */ - ret = cs_etm__etmq_update_thread(etmq, tidq->packet->el, - tidq->packet->tid, - &tidq->frontend_thread); + ret = cs_etm__context(etmq, tidq); if (ret) goto out; break; @@ -3536,6 +3599,14 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, PERF_IP_FLAG_TRACE_BEGIN | PERF_IP_FLAG_TRACE_END;
+ 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; + } + } + etm->session = session;
etm->num_cpu = num_cpu; @@ -3587,9 +3658,11 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, }
etm->use_thread_stack = etm->synth_opts.thread_stack || - etm->synth_opts.last_branch; + etm->synth_opts.last_branch || + etm->synth_opts.callchain;
- etm->use_callchain = etm->synth_opts.thread_stack; + etm->use_callchain = etm->synth_opts.thread_stack || + etm->synth_opts.callchain;
err = cs_etm__synth_events(etm, session); if (err)