Messages in this thread Patch in this message | | | From | Tiezhu Yang <> | Subject | [PATCH] perf callchain: Return directly when use '--call-graph dwarf' under !CONFIG_DWARF | Date | Mon, 14 Dec 2020 20:56:55 +0800 |
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DWARF register mappings have not been defined for some architectures, at least for mips, so we can print an error message and then return directly when use '--call-graph dwarf'.
E.g. without this patch:
[root@linux perf]# ./perf record --call-graph dwarf cd Error: The sys_perf_event_open() syscall returned with 89 (Function not implemented) for event (cycles). /bin/dmesg | grep -i perf may provide additional information.
With this patch:
[root@linux perf]# ./perf record --call-graph dwarf cd DWARF is not supported for architecture mips64
Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>]
--call-graph <record_mode[,record_size]> setup and enables call-graph (stack chain/backtrace):
record_mode: call graph recording mode (fp|dwarf|lbr) record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>) default: 8192 (bytes)
Default: fp
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> --- tools/perf/util/callchain.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index 1b60985..a8cf456 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -18,6 +18,7 @@ #include <math.h> #include <linux/string.h> #include <linux/zalloc.h> +#include <sys/utsname.h> #include "asm/bug.h" @@ -278,6 +279,16 @@ int parse_callchain_record(const char *arg, struct callchain_param *param) } else if (!strncmp(name, "dwarf", sizeof("dwarf"))) { const unsigned long default_stack_dump_size = 8192; + if (system("grep -q 'CONFIG_DWARF=y' .config-detected") != 0) { + struct utsname uts; + + ret = uname(&uts); + pr_err("DWARF is not supported for architecture %s\n", + ret ? "unknown" : uts.machine); + + return -ENOTSUP; + } + ret = 0; param->record_mode = CALLCHAIN_DWARF; param->dump_size = default_stack_dump_size; -- 2.1.0
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