On Sat, Oct 05, 2019 at 05:16:13PM +0800, Leo Yan wrote:
Now CoreSight has supported the thread stack; based on the thread stack we can synthesize call chain for the instruction sample; the call chain can be injected by option '--itrace=g'.
Before:
# perf script --itrace=g16l64i100 main 1579 100 instructions: ffff0000102137f0 group_sched_in+0xb0 ([kernel.kallsyms]) main 1579 100 instructions: ffff000010213b78 flexible_sched_in+0xf0 ([kernel.kallsyms]) main 1579 100 instructions: ffff0000102135ac event_sched_in.isra.57+0x74 ([kernel.kallsyms]) main 1579 100 instructions: ffff000010219344 perf_swevent_add+0x6c ([kernel.kallsyms]) main 1579 100 instructions: ffff000010214854 perf_event_update_userpage+0x4c ([kernel.kallsyms]) [...]
After:
# perf script --itrace=g16l64i100
main 1579 100 instructions: ffff000010213b78 flexible_sched_in+0xf0 ([kernel.kallsyms]) ffff00001020c0b4 visit_groups_merge+0x12c ([kernel.kallsyms])
main 1579 100 instructions: ffff0000102135ac event_sched_in.isra.57+0x74 ([kernel.kallsyms]) ffff0000102137a0 group_sched_in+0x60 ([kernel.kallsyms]) ffff000010213b84 flexible_sched_in+0xfc ([kernel.kallsyms]) ffff00001020c0b4 visit_groups_merge+0x12c ([kernel.kallsyms])
main 1579 100 instructions: ffff000010219344 perf_swevent_add+0x6c ([kernel.kallsyms]) ffff0000102135f4 event_sched_in.isra.57+0xbc ([kernel.kallsyms]) ffff0000102137a0 group_sched_in+0x60 ([kernel.kallsyms]) ffff000010213b84 flexible_sched_in+0xfc ([kernel.kallsyms]) ffff00001020c0b4 visit_groups_merge+0x12c ([kernel.kallsyms]) [...]
Signed-off-by: Leo Yan leo.yan@linaro.org
tools/perf/util/cs-etm.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 4b42f9c9bd34..56e501cd2f5f 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" @@ -74,6 +75,7 @@ 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;
@@ -251,6 +253,16 @@ 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);
@@ -275,6 +287,7 @@ 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);
Theoretically this should go two lines up, i.e just below zfree(&tidq->prev_packet). If you agree with the comment I did in 3/6 then it is worth doing the above change, otherwise it can stay that way.
out: return rc; } @@ -546,6 +559,7 @@ 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);
Same comment as above. The rest looks good to me.
Mathieu
zfree(&tidq);/* @@ -1126,7 +1140,7 @@ static void cs_etm__add_stack_event(struct cs_etm_queue *etmq, int insn_len; u64 from_ip, to_ip;
- if (etm->synth_opts.thread_stack) {
- 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);
@@ -1182,6 +1196,14 @@ 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;
@@ -1369,6 +1391,8 @@ 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;@@ -2639,7 +2663,6 @@ 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;@@ -2651,6 +2674,14 @@ int cs_etm__process_auxtrace_info(union perf_event *event, etm->branches_filter |= PERF_IP_FLAG_RETURN | PERF_IP_FLAG_TRACE_BEGIN;
- 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); if (err) goto err_delete_thread;
-- 2.17.1