From cb1dc22dce6e54dbd1eac213c9216e1aa57084da Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 18 Nov 2015 08:52:47 +0100 Subject: [PATCH] perf callchain: Add order support for libunwind DWARF unwinder 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 libunwind DWARF unwinder, so we could get following output for report: $ perf record --call-graph dwarf ls ... $ perf report --no-children --stdio 39.26% ls libc-2.21.so [.] __strcoll_l | ---__strcoll_l mpsort_with_tmp mpsort_with_tmp sort_files main __libc_start_main _start 0 $ perf report -g caller --no-children --stdio ... 39.26% ls libc-2.21.so [.] __strcoll_l | ---0 _start __libc_start_main main sort_files mpsort_with_tmp mpsort_with_tmp __strcoll_l Based-on-patch-by: Milian Wolff Reported-and-Tested-by: Milian Wolff Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Tested-by: Wang Nan Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/20151118075247.GA5416@krava.brq.redhat.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/unwind-libunwind.c | 47 +++++++++++++++++++----------- 1 file changed, 30 insertions(+), 17 deletions(-) diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c index 0ae8844fe7a6..3c258a0e4092 100644 --- a/tools/perf/util/unwind-libunwind.c +++ b/tools/perf/util/unwind-libunwind.c @@ -615,34 +615,47 @@ static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, void *arg, int max_stack) { u64 val; + unw_word_t ips[max_stack]; unw_addr_space_t addr_space; unw_cursor_t c; - int ret; + int ret, i = 0; ret = perf_reg_value(&val, &ui->sample->user_regs, PERF_REG_IP); if (ret) return ret; - ret = entry(val, ui->thread, cb, arg); - if (ret) - return -ENOMEM; + ips[i++] = (unw_word_t) val; - if (--max_stack == 0) - return 0; - - addr_space = thread__priv(ui->thread); - if (addr_space == NULL) - return -1; + /* + * If we need more than one entry, do the DWARF + * unwind itself. + */ + if (max_stack - 1 > 0) { + addr_space = thread__priv(ui->thread); + if (addr_space == NULL) + return -1; + + ret = unw_init_remote(&c, addr_space, ui); + if (ret) + display_error(ret); + + while (!ret && (unw_step(&c) > 0) && i < max_stack) { + unw_get_reg(&c, UNW_REG_IP, &ips[i]); + ++i; + } - ret = unw_init_remote(&c, addr_space, ui); - if (ret) - display_error(ret); + max_stack = i; + } - while (!ret && (unw_step(&c) > 0) && max_stack--) { - unw_word_t ip; + /* + * Display what we got based on the order setup. + */ + for (i = 0; i < max_stack && !ret; i++) { + int j = i; - unw_get_reg(&c, UNW_REG_IP, &ip); - ret = ip ? entry(ip, ui->thread, cb, arg) : 0; + if (callchain_param.order == ORDER_CALLER) + j = max_stack - i - 1; + ret = ips[j] ? entry(ips[j], ui->thread, cb, arg) : 0; } return ret; -- 2.30.2