From: Kan Liang <[email protected]> LBR call stack only has user callchain. It is output as PERF_SAMPLE_BRANCH_STACK data format. For the kernel callchain, it's still from PERF_SAMPLE_CALLCHAIN. The perf tool has to handle both data sources to construct a complete callstack.
Signed-off-by: Kan Liang <[email protected]> --- tools/perf/util/machine.c | 194 ++++++++++++++++++++++++++++++---------------- tools/perf/util/session.c | 41 ++++++++-- 2 files changed, 163 insertions(+), 72 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 52e9490..f51014f 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1399,18 +1399,70 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample, return bi; } +static inline int __thread__resolve_callchain_sample(struct thread *thread, + u64 ip, u8 *cpumode, + struct symbol **parent, + struct addr_location *root_al, + struct addr_location *al) +{ + if (ip >= PERF_CONTEXT_MAX) { + switch (ip) { + case PERF_CONTEXT_HV: + *cpumode = PERF_RECORD_MISC_HYPERVISOR; + break; + case PERF_CONTEXT_KERNEL: + *cpumode = PERF_RECORD_MISC_KERNEL; + break; + case PERF_CONTEXT_USER: + *cpumode = PERF_RECORD_MISC_USER; + break; + default: + pr_debug("invalid callchain context: " + "%"PRId64"\n", (s64) ip); + /* + * It seems the callchain is corrupted. + * Discard all. + */ + callchain_cursor_reset(&callchain_cursor); + return 1; + } + return 0; + } + + al->filtered = 0; + thread__find_addr_location(thread, *cpumode, + MAP__FUNCTION, ip, al); + if (al->sym != NULL) { + if (sort__has_parent && !*parent && + symbol__match_regex(al->sym, &parent_regex)) + *parent = al->sym; + else if (have_ignore_callees && root_al && + symbol__match_regex(al->sym, &ignore_callees_regex)) { + /* Treat this symbol as the root, + forgetting its callees. */ + *root_al = *al; + callchain_cursor_reset(&callchain_cursor); + } + } + + return callchain_cursor_append(&callchain_cursor, + ip, al->map, al->sym); +} + static int thread__resolve_callchain_sample(struct thread *thread, - struct ip_callchain *chain, - struct symbol **parent, - struct addr_location *root_al, - int max_stack) + struct perf_evsel *evsel, + struct perf_sample *sample, + struct symbol **parent, + struct addr_location *root_al, + int max_stack) { + struct ip_callchain *chain = sample->callchain; u8 cpumode = PERF_RECORD_MISC_USER; int chain_nr = min(max_stack, (int)chain->nr); - int i; - int j; - int err; + int i, j, err = 0; int skip_idx __maybe_unused; + int lbr = 0; + u64 ip; callchain_cursor_reset(&callchain_cursor); @@ -1419,74 +1471,81 @@ static int thread__resolve_callchain_sample(struct thread *thread, return 0; } - /* - * Based on DWARF debug information, some architectures skip - * a callchain entry saved by the kernel. - */ - skip_idx = arch_skip_callchain_idx(thread, chain); + if (evsel->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK) + lbr = 1; - for (i = 0; i < chain_nr; i++) { - u64 ip; - struct addr_location al; +again: + /* LBR call stack */ + if (lbr) { + struct branch_stack *lbr_stack = sample->branch_stack; + int lbr_nr = lbr_stack->nr; + int mix_chain_nr; - if (callchain_param.order == ORDER_CALLEE) - j = i; - else - j = chain->nr - i - 1; + for (i = 0; i < chain_nr; i++) { + if (chain->ips[i] == PERF_CONTEXT_USER) + break; + } -#ifdef HAVE_SKIP_CALLCHAIN_IDX - if (j == skip_idx) - continue; -#endif - ip = chain->ips[j]; + /* LBR only affects the user callchain */ + if (i == chain_nr) { + lbr = 0; + goto again; + } - if (ip >= PERF_CONTEXT_MAX) { - switch (ip) { - case PERF_CONTEXT_HV: - cpumode = PERF_RECORD_MISC_HYPERVISOR; - break; - case PERF_CONTEXT_KERNEL: - cpumode = PERF_RECORD_MISC_KERNEL; - break; - case PERF_CONTEXT_USER: - cpumode = PERF_RECORD_MISC_USER; - break; - default: - pr_debug("invalid callchain context: " - "%"PRId64"\n", (s64) ip); - /* - * It seems the callchain is corrupted. - * Discard all. - */ - callchain_cursor_reset(&callchain_cursor); - return 0; - } - continue; + mix_chain_nr = i + 2 + lbr_nr; + if (mix_chain_nr > PERF_MAX_STACK_DEPTH) { + pr_warning("corrupted callchain. skipping...\n"); + return 0; } - al.filtered = 0; - thread__find_addr_location(thread, cpumode, - MAP__FUNCTION, ip, &al); - if (al.sym != NULL) { - if (sort__has_parent && !*parent && - symbol__match_regex(al.sym, &parent_regex)) - *parent = al.sym; - else if (have_ignore_callees && root_al && - symbol__match_regex(al.sym, &ignore_callees_regex)) { - /* Treat this symbol as the root, - forgetting its callees. */ - *root_al = al; - callchain_cursor_reset(&callchain_cursor); + for (j = 0; j < mix_chain_nr; j++) { + struct addr_location al; + + if (callchain_param.order == ORDER_CALLEE) { + if (j < i + 2) + ip = chain->ips[j]; + else + ip = lbr_stack->entries[j - i - 2].from; + } else { + if (j < lbr_nr) + ip = lbr_stack->entries[lbr_nr - j - 1].from; + else + ip = chain->ips[i + 1 - (j - lbr_nr)]; } + err = __thread__resolve_callchain_sample(thread, + ip, &cpumode, parent, root_al, &al); + if (err) + goto exit; } + } else { - err = callchain_cursor_append(&callchain_cursor, - ip, al.map, al.sym); - if (err) - return err; - } + /* + * Based on DWARF debug information, some architectures skip + * a callchain entry saved by the kernel. + */ + skip_idx = arch_skip_callchain_idx(thread, chain); - return 0; + for (i = 0; i < chain_nr; i++) { + struct addr_location al; + + if (callchain_param.order == ORDER_CALLEE) + j = i; + else + j = chain->nr - i - 1; + +#ifdef HAVE_SKIP_CALLCHAIN_IDX + if (j == skip_idx) + continue; +#endif + ip = chain->ips[j]; + err = __thread__resolve_callchain_sample(thread, + ip, &cpumode, parent, root_al, &al); + if (err) + goto exit; + } + } +exit: + return (err < 0) ? err : 0; } static int unwind_entry(struct unwind_entry *entry, void *arg) @@ -1503,8 +1562,9 @@ int thread__resolve_callchain(struct thread *thread, struct addr_location *root_al, int max_stack) { - int ret = thread__resolve_callchain_sample(thread, sample->callchain, - parent, root_al, max_stack); + int ret = thread__resolve_callchain_sample(thread, evsel, + sample, parent, + root_al, max_stack); if (ret) return ret; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index f4478ce..fa476be 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -557,15 +557,45 @@ int perf_session_queue_event(struct perf_session *s, union perf_event *event, return 0; } -static void callchain__printf(struct perf_sample *sample) +static void callchain__printf(struct perf_evsel *evsel, + struct perf_sample *sample) { unsigned int i; + u64 total_nr, callchain_nr; + int lbr = 0; - printf("... chain: nr:%" PRIu64 "\n", sample->callchain->nr); + total_nr = callchain_nr = sample->callchain->nr; - for (i = 0; i < sample->callchain->nr; i++) + if (evsel->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK) + lbr = 1; + + if (lbr) { + struct branch_stack *lbr_stack = sample->branch_stack; + + for (i = 0; i < callchain_nr; i++) { + if (sample->callchain->ips[i] == PERF_CONTEXT_USER) + break; + } + + if (i != callchain_nr) { + total_nr = i + 1 + lbr_stack->nr; + callchain_nr = i + 1; + } + } + + printf("... chain: nr:%" PRIu64 "\n", total_nr); + + for (i = 0; i < callchain_nr + 1; i++) printf("..... %2d: %016" PRIx64 "\n", i, sample->callchain->ips[i]); + + if (total_nr > callchain_nr) { + struct branch_stack *lbr_stack = sample->branch_stack; + + for (i = 0; i < lbr_stack->nr; i++) + printf("..... %2d: %016" PRIx64 "\n", + (int)(i + callchain_nr + 1), lbr_stack->entries[i].from); + } } static void branch_stack__printf(struct perf_sample *sample) @@ -691,9 +721,10 @@ static void dump_sample(struct perf_evsel *evsel, union perf_event *event, sample_type = evsel->attr.sample_type; if (sample_type & PERF_SAMPLE_CALLCHAIN) - callchain__printf(sample); + callchain__printf(evsel, sample); - if (sample_type & PERF_SAMPLE_BRANCH_STACK) + if ((sample_type & PERF_SAMPLE_BRANCH_STACK) && + !(evsel->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK)) branch_stack__printf(sample); if (sample_type & PERF_SAMPLE_REGS_USER) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
