From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BF33C2BB48 for ; Mon, 14 Dec 2020 13:41:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB0DB229F0 for ; Mon, 14 Dec 2020 13:41:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728162AbgLNNk5 (ORCPT ); Mon, 14 Dec 2020 08:40:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:37494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390539AbgLNNkU (ORCPT ); Mon, 14 Dec 2020 08:40:20 -0500 Date: Mon, 14 Dec 2020 10:39:50 -0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607953179; bh=AMC5CQEhi9XfiB5U/3SFE1EIz5yjn0jMNgojfbpGWuE=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=RirpLR0LlxsoiOlfC0vwwnESoVQuUHbw3Q60GM2BiN28bWyLbUuEdPczV68sZASo2 UMz0PcaLhePvnhwmNz9zRo3go4+64iQOmcfxBekW67U5fIeEdQ6stAgpSe5NzcKLKv /MjSOidCthsI6+i55uDyU5Jl66utYAHmLiN46CXAzNbh/n0PmytQZR6BQ7iloS4xCY 0Gow2uw2sVB5zxGESjH8uJH6VFTW0Fy8q9qORg52tsdAfefhRixcgqEMznHgh2h+yy ZyTWHkoA7u/OuFzy/+m9HZsWtH1jG0hiQdCaHlWV05yCJBUKK2Sq7vpEg0jTM+Iow9 P5kLSlR1eFIiQ== From: Arnaldo Carvalho de Melo To: Tiezhu Yang Cc: Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org, Xuefeng Li Subject: Re: [PATCH] perf callchain: Return directly when use '--call-graph dwarf' under !CONFIG_DWARF Message-ID: <20201214133950.GE238399@kernel.org> References: <1607950615-11825-1-git-send-email-yangtiezhu@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1607950615-11825-1-git-send-email-yangtiezhu@loongson.cn> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Dec 14, 2020 at 08:56:55PM +0800, Tiezhu Yang escreveu: > 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 Good improvement on the message! But that .config-detected file isn't available at run time, take a look if this isn't a better alternative: diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index 1b60985690bba313..125178fd17482513 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -276,6 +276,7 @@ int parse_callchain_record(const char *arg, struct callchain_param *param) /* Dwarf style */ } else if (!strncmp(name, "dwarf", sizeof("dwarf"))) { +#ifdef HAVE_DWARF_SUPPORT const unsigned long default_stack_dump_size = 8192; ret = 0; @@ -290,6 +291,15 @@ int parse_callchain_record(const char *arg, struct callchain_param *param) ret = get_stack_size(tok, &size); param->dump_size = size; } +#else + struct utsname uts; + + ret = uname(&uts); + pr_err("DWARF is not supported for architecture %s\n", + ret ? "unknown" : uts.machine); + + return -ENOTSUP; +#endif } else if (!strncmp(name, "lbr", sizeof("lbr"))) { if (!strtok_r(NULL, ",", &saveptr)) { param->record_mode = CALLCHAIN_LBR; > Usage: perf record [] [] > or: perf record [] -- [] > > --call-graph > 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 () > default: 8192 (bytes) > > Default: fp > > Signed-off-by: Tiezhu Yang > --- > 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 > #include > #include > +#include > > #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 > -- - Arnaldo