Messages in this thread Patch in this message | | | From | Mark Santaniello <> | Subject | [PATCH 1/2] Support perf script -F brstack,dso and brstacksym,dso | Date | Mon, 19 Jun 2017 09:38:24 -0700 |
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Perf script can report the dso for "addr" and "ip" fields. This adds the same support for the "brstack" and "brstacksym" fields. This can be helpful for AutoFDO: we can ignore LBR entries unless the source and target address are both in the target module we are about to build.
I built a small test akin to "while(1) { do_nothing(); }" where the do_nothing function is loaded from a dso:
~/src/burncpu$ cat burncpu.cpp #include <dlfcn.h>
int main() { void* handle = dlopen("./dso.so", RTLD_LAZY); if (!handle) return -1;
typedef void (*fp)(); fp do_nothing = (fp) dlsym(handle, "do_nothing");
while(1) { do_nothing(); } }
~/src/burncpu$ cat dso.cpp extern "C" void do_nothing() {}
~/src/burncpu$ cat build.sh #!/bin/bash g++ -shared dso.cpp -o dso.so g++ burncpu.cpp -o burncpu -ldl
I sampled the execution with perf record -b. Using the new perf script functionality I can easily find cases where there was a transition from one dso to another:
$ ./perf record -a -b -- sleep 5 [ perf record: Woken up 55 times to write data ] [ perf record: Captured and wrote 18.815 MB perf.data (43593 samples) ]
$ ./perf script -F brstack,dso | sed 's/\/0 /\/0\n/g' \ > | grep burncpu | grep dso.so | head -n 1 0x7f967139b6aa(/tmp/burncpu/dso.so)/0x4006b1(/tmp/burncpu/exe)/P/-/-/0
$ ./perf script -F brstacksym,dso | sed 's/\/0 /\/0\n/g' \ > | grep burncpu | grep dso.so | head -n 1 do_nothing+0x5(/tmp/burncpu/dso.so)/main+0x44(/tmp/burncpu/exe)/P/-/-/0
Signed-off-by: Mark Santaniello <marksan@fb.com> --- tools/perf/builtin-script.c | 61 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 49 insertions(+), 12 deletions(-)
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 4761b0d..6a7033b 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -298,10 +298,11 @@ static int perf_evsel__check_attr(struct perf_evsel *evsel, "selected.\n"); return -EINVAL; } - if (PRINT_FIELD(DSO) && !PRINT_FIELD(IP) && !PRINT_FIELD(ADDR)) { - pr_err("Display of DSO requested but neither sample IP nor " - "sample address\nis selected. Hence, no addresses to convert " - "to DSO.\n"); + if (PRINT_FIELD(DSO) && !PRINT_FIELD(IP) && !PRINT_FIELD(ADDR) && + !PRINT_FIELD(BRSTACK) && !PRINT_FIELD(BRSTACKSYM)) { + pr_err("Display of DSO requested but none of sample IP, sample address, " + "brstack\nor brstacksym are selected. Hence, no addresses to " + "convert to DSO.\n"); return -EINVAL; } if (PRINT_FIELD(SRCLINE) && !PRINT_FIELD(IP)) { @@ -514,18 +515,43 @@ mispred_str(struct branch_entry *br) return br->flags.predicted ? 'P' : 'M'; } -static void print_sample_brstack(struct perf_sample *sample) +static void print_sample_brstack(struct perf_sample *sample, + struct thread *thread, + struct perf_event_attr *attr) { struct branch_stack *br = sample->branch_stack; - u64 i; + struct addr_location alf, alt; + u64 i, from, to; if (!(br && br->nr)) return; for (i = 0; i < br->nr; i++) { - printf(" 0x%"PRIx64"/0x%"PRIx64"/%c/%c/%c/%d ", - br->entries[i].from, - br->entries[i].to, + from = br->entries[i].from; + to = br->entries[i].to; + + if (PRINT_FIELD(DSO)) { + memset(&alf, 0, sizeof(alf)); + memset(&alt, 0, sizeof(alt)); + thread__find_addr_map(thread, sample->cpumode, MAP__FUNCTION, from, &alf); + thread__find_addr_map(thread, sample->cpumode, MAP__FUNCTION, to, &alt); + } + + printf("0x%"PRIx64, from); + if (PRINT_FIELD(DSO)) { + printf("("); + map__fprintf_dsoname(alf.map, stdout); + printf(")"); + } + + printf("/0x%"PRIx64, to); + if (PRINT_FIELD(DSO)) { + printf("("); + map__fprintf_dsoname(alt.map, stdout); + printf(")"); + } + + printf("/%c/%c/%c/%d ", mispred_str( br->entries + i), br->entries[i].flags.in_tx? 'X' : '-', br->entries[i].flags.abort? 'A' : '-', @@ -534,7 +560,8 @@ static void print_sample_brstack(struct perf_sample *sample) } static void print_sample_brstacksym(struct perf_sample *sample, - struct thread *thread) + struct thread *thread, + struct perf_event_attr *attr) { struct branch_stack *br = sample->branch_stack; struct addr_location alf, alt; @@ -559,8 +586,18 @@ static void print_sample_brstacksym(struct perf_sample *sample, alt.sym = map__find_symbol(alt.map, alt.addr); symbol__fprintf_symname_offs(alf.sym, &alf, stdout); + if (PRINT_FIELD(DSO)) { + printf("("); + map__fprintf_dsoname(alf.map, stdout); + printf(")"); + } putchar('/'); symbol__fprintf_symname_offs(alt.sym, &alt, stdout); + if (PRINT_FIELD(DSO)) { + printf("("); + map__fprintf_dsoname(alt.map, stdout); + printf(")"); + } printf("/%c/%c/%c/%d ", mispred_str( br->entries + i), br->entries[i].flags.in_tx? 'X' : '-', @@ -1187,9 +1224,9 @@ static void process_event(struct perf_script *script, print_sample_iregs(sample, attr); if (PRINT_FIELD(BRSTACK)) - print_sample_brstack(sample); + print_sample_brstack(sample, thread, attr); else if (PRINT_FIELD(BRSTACKSYM)) - print_sample_brstacksym(sample, thread); + print_sample_brstacksym(sample, thread, attr); if (perf_evsel__is_bpf_output(evsel) && PRINT_FIELD(BPF_OUTPUT)) print_sample_bpf_output(sample); -- 2.9.3
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