Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 4/7] perf callchain: Add order support for libdw DWARF unwinder | Date | Mon, 23 Nov 2015 18:53:51 -0300 |
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From: Jiri Olsa <jolsa@redhat.com>
As reported by Milian, currently for DWARF unwind (both libdw and libunwind) we display callchain in callee order only.
Adding the support to follow callchain order setup to libdw DWARF unwinder, so we could get following output for report:
$ perf record --call-graph dwarf ls ...
$ perf report --no-children --stdio
21.12% ls libc-2.21.so [.] __strcoll_l | ---__strcoll_l mpsort_with_tmp mpsort_with_tmp mpsort_with_tmp sort_files main __libc_start_main _start
$ perf report --stdio --no-children -g caller
21.12% ls libc-2.21.so [.] __strcoll_l | ---_start __libc_start_main main sort_files mpsort_with_tmp mpsort_with_tmp mpsort_with_tmp __strcoll_l
Reported-by: Milian Wolff <milian.wolff@kdab.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Wang Nan <wangnan0@huawei.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jan Kratochvil <jkratoch@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20151119130119.GA26617@krava.brq.redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/unwind-libdw.c | 53 ++++++++++++++++++++++++++++++------------ tools/perf/util/unwind-libdw.h | 2 ++ 2 files changed, 40 insertions(+), 15 deletions(-)
diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c index 2dcfe9a7c8d0..db8142ba7cb9 100644 --- a/tools/perf/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw.c @@ -11,6 +11,7 @@ #include <linux/types.h> #include "event.h" #include "perf_regs.h" +#include "callchain.h" static char *debuginfo_path; @@ -52,25 +53,28 @@ static int report_module(u64 ip, struct unwind_info *ui) return __report_module(&al, ip, ui); } +/* + * Store all entries within entries array, + * we will process it after we finish unwind. + */ static int entry(u64 ip, struct unwind_info *ui) { - struct unwind_entry e; + struct unwind_entry *e = &ui->entries[ui->idx++]; struct addr_location al; if (__report_module(&al, ip, ui)) return -1; - e.ip = ip; - e.map = al.map; - e.sym = al.sym; + e->ip = ip; + e->map = al.map; + e->sym = al.sym; pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n", al.sym ? al.sym->name : "''", ip, al.map ? al.map->map_ip(al.map, ip) : (u64) 0); - - return ui->cb(&e, ui->arg); + return 0; } static pid_t next_thread(Dwfl *dwfl, void *arg, void **thread_argp) @@ -168,7 +172,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, struct perf_sample *data, int max_stack) { - struct unwind_info ui = { + struct unwind_info *ui, ui_buf = { .sample = data, .thread = thread, .machine = thread->mg->machine, @@ -177,35 +181,54 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, .max_stack = max_stack, }; Dwarf_Word ip; - int err = -EINVAL; + int err = -EINVAL, i; if (!data->user_regs.regs) return -EINVAL; - ui.dwfl = dwfl_begin(&offline_callbacks); - if (!ui.dwfl) + ui = zalloc(sizeof(ui_buf) + sizeof(ui_buf.entries[0]) * max_stack); + if (!ui) + return -ENOMEM; + + *ui = ui_buf; + + ui->dwfl = dwfl_begin(&offline_callbacks); + if (!ui->dwfl) goto out; err = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP); if (err) goto out; - err = report_module(ip, &ui); + err = report_module(ip, ui); if (err) goto out; - if (!dwfl_attach_state(ui.dwfl, EM_NONE, thread->tid, &callbacks, &ui)) + if (!dwfl_attach_state(ui->dwfl, EM_NONE, thread->tid, &callbacks, ui)) goto out; - err = dwfl_getthread_frames(ui.dwfl, thread->tid, frame_callback, &ui); + err = dwfl_getthread_frames(ui->dwfl, thread->tid, frame_callback, ui); - if (err && !ui.max_stack) + if (err && !ui->max_stack) err = 0; + /* + * Display what we got based on the order setup. + */ + for (i = 0; i < ui->idx && !err; i++) { + int j = i; + + if (callchain_param.order == ORDER_CALLER) + j = ui->idx - i - 1; + + err = ui->entries[j].ip ? ui->cb(&ui->entries[j], ui->arg) : 0; + } + out: if (err) pr_debug("unwind: failed with '%s'\n", dwfl_errmsg(-1)); - dwfl_end(ui.dwfl); + dwfl_end(ui->dwfl); + free(ui); return 0; } diff --git a/tools/perf/util/unwind-libdw.h b/tools/perf/util/unwind-libdw.h index 417a1426f3ad..58328669ed16 100644 --- a/tools/perf/util/unwind-libdw.h +++ b/tools/perf/util/unwind-libdw.h @@ -16,6 +16,8 @@ struct unwind_info { unwind_entry_cb_t cb; void *arg; int max_stack; + int idx; + struct unwind_entry entries[]; }; #endif /* __PERF_UNWIND_LIBDW_H */ -- 2.1.0
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