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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 9BA1BC33C8C for ; Mon, 6 Jan 2020 14:33:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60AE0207FD for ; Mon, 6 Jan 2020 14:33:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ki03YYpR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726422AbgAFOd7 (ORCPT ); Mon, 6 Jan 2020 09:33:59 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:46589 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726307AbgAFOd6 (ORCPT ); Mon, 6 Jan 2020 09:33:58 -0500 Received: by mail-pg1-f196.google.com with SMTP id z124so26950582pgb.13 for ; Mon, 06 Jan 2020 06:33:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BatzYnC4FswhR3C1Q5mhXYj5UWHTlHYMvJHbWAt9+ao=; b=Ki03YYpRnKoNdaSSebUzbUyDIM9aS3ld+rxOlN08pvKPurSvWLJCzsGkXpbSgNe+wN 7KVWfEw+/Q+I7FCPBDzOiQ37dhZkuw3XRzENYyE8NrIV+nkXx3ukQTYBCCfYnLfgi9d+ STdQhT44EsaFxoLiOIlkI92j3/DeyETVmGyzp1/VToY1EiAyTMKIHGUdOz36tAm9hOo8 AGtXxEo5KCDHFauavdA6n6nXi9eUwXt57Kp2U0/qtDnu+cyyYIqXs0miO5LfQuePLW8e XZ4qrpCcepm+D8mzqA4wa77gAQz1UJGxWdjk1L2Z4+o7l7oWefGW6sGahBFePAyJPRn0 o+vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BatzYnC4FswhR3C1Q5mhXYj5UWHTlHYMvJHbWAt9+ao=; b=dFQh8QnVTVfxOed4J1/IPHUzozfaPRTQtDhsdPf+QNi/qFqR8g+c2f4UoIhtkdnVy/ aPJ92UlGSaTH0oRULSPvD6nzhZBPXqe4q3NIQUT2Tma2sgsu2JjP/ppaQbXkumVU9a5k c/C9NhQam6lnpZEaYdmON3jdSxriAjX90pHmWA7r2kTaU5kMGn5tO2J1SoFhgXZrLspj ilmdjFCDKyugtiU30iFBTHp0qFdM++tw9q9jCFeY+lQJWBff7i96uwK8jyOsPW4Itr7C cTr3dz6NIllGg0dan7Q4C2bdHhSeE3TTTZSY98EJoelJglrdbcjmtX9+PiZcPuQag81V cdng== X-Gm-Message-State: APjAAAV0V+OuppdxiuMzd+g0ckrsU3az+p6AleS4s0C8+FqlR9NWp18F uhdpQaPuc9tHXbSC+fXMUrpYiwmZL8pn/9M6zfU= X-Google-Smtp-Source: APXvYqwVtIP0D37jnPdw5/R0h4kqwEJsgBftRb8opQhfXxN9ZrxOFePLPAES5TlArTMpKT3fM6TAR8GiNUtH33KwnCg= X-Received: by 2002:a62:7883:: with SMTP id t125mr112594929pfc.141.1578321238167; Mon, 06 Jan 2020 06:33:58 -0800 (PST) MIME-Version: 1.0 References: <20191213153029.133570-1-tz.stoyanov@gmail.com> <20191213153029.133570-11-tz.stoyanov@gmail.com> <20191220150413.5d1c52e5@gandalf.local.home> In-Reply-To: <20191220150413.5d1c52e5@gandalf.local.home> From: Tzvetomir Stoyanov Date: Mon, 6 Jan 2020 16:33:47 +0200 Message-ID: Subject: Re: [PATCH v18 10/18] trace-cmd: Store the session tracing ID in the trace.dat file To: Steven Rostedt Cc: linux-trace-devel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Fri, Dec 20, 2019 at 10:04 PM Steven Rostedt wrote: > > On Fri, 13 Dec 2019 17:30:21 +0200 > "Tzvetomir Stoyanov (VMware)" wrote: > > > The ID of the current tracing session is stored in the trace.dat file. > > A new file option is introduced: > > TRACECMD_OPTION_TRACEID > > The data is stored in the file as NULL terminated string: > > "\nTraceID: %llu\n" > > If the trace ID is just a 64 bit number, why is it stored in the file > as a string? > The only reason for this is to avoid endian long long conversions, and to simplify reading of trace.dat file, for debug purposes. > -- Steve > > > > A new libtracecmd API is introduced, to get the ID when the trace.dat file is read: > > unsigned long long tracecmd_get_traceid(struct tracecmd_input *handle); > > > > Signed-off-by: Tzvetomir Stoyanov (VMware) > > --- > > include/trace-cmd/trace-cmd.h | 2 ++ > > lib/trace-cmd/trace-input.c | 25 +++++++++++++++++++++++++ > > tracecmd/trace-record.c | 15 +++++++++++++++ > > 3 files changed, 42 insertions(+) > > > > diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h > > index ad69313..6cc2913 100644 > > --- a/include/trace-cmd/trace-cmd.h > > +++ b/include/trace-cmd/trace-cmd.h > > @@ -86,6 +86,7 @@ enum { > > TRACECMD_OPTION_CPUCOUNT, > > TRACECMD_OPTION_VERSION, > > TRACECMD_OPTION_PROCMAPS, > > + TRACECMD_OPTION_TRACEID, > > }; > > > > enum { > > @@ -128,6 +129,7 @@ int tracecmd_copy_headers(struct tracecmd_input *handle, int fd); > > void tracecmd_set_flag(struct tracecmd_input *handle, int flag); > > void tracecmd_clear_flag(struct tracecmd_input *handle, int flag); > > unsigned long tracecmd_get_flags(struct tracecmd_input *handle); > > +unsigned long long tracecmd_get_traceid(struct tracecmd_input *handle); > > > > void tracecmd_parse_trace_clock(struct tracecmd_input *handle, char *file, int size); > > > > diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c > > index 91362f3..40d9825 100644 > > --- a/lib/trace-cmd/trace-input.c > > +++ b/lib/trace-cmd/trace-input.c > > @@ -79,6 +79,7 @@ struct tracecmd_input { > > struct tep_plugin_list *plugin_list; > > struct tracecmd_input *parent; > > unsigned long flags; > > + unsigned long long trace_id; > > int fd; > > int long_size; > > int page_size; > > @@ -2169,6 +2170,15 @@ static void procmap_free(struct pid_addr_maps *maps) > > free(maps); > > } > > > > +static int trace_traceid_load(struct tracecmd_input *handle, char *buf) > > +{ > > + > > + if (sscanf(buf, "%*s %llu", &handle->trace_id) == 1) > > + return 0; > > + > > + return -1; > > +} > > + > > #define STR_PROCMAP_LINE_MAX (PATH_MAX+22) > > static int trace_pid_map_load(struct tracecmd_input *handle, char *buf) > > { > > @@ -2406,6 +2416,10 @@ static int handle_options(struct tracecmd_input *handle) > > if (buf[size-1] == '\0') > > trace_pid_map_load(handle, buf); > > break; > > + case TRACECMD_OPTION_TRACEID: > > + if (buf[size-1] == '\0') > > + trace_traceid_load(handle, buf); > > + break; > > default: > > warning("unknown option %d", option); > > break; > > @@ -3507,3 +3521,14 @@ void tracecmd_set_show_data_func(struct tracecmd_input *handle, > > { > > handle->show_data_func = func; > > } > > + > > +/** > > + * tracecmd_get_traceid - get the trace id of the session > > + * @handle: input handle for the trace.dat file > > + * > > + * Returns the trace id, written in the trace file > > + */ > > +unsigned long long tracecmd_get_traceid(struct tracecmd_input *handle) > > +{ > > + return handle->trace_id; > > +} > > diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c > > index 7089f7b..b65aeb2 100644 > > --- a/tracecmd/trace-record.c > > +++ b/tracecmd/trace-record.c > > @@ -3714,6 +3714,19 @@ add_pid_maps(struct tracecmd_output *handle, struct buffer_instance *instance) > > trace_seq_destroy(&s); > > } > > > > +static void > > +add_trace_id(struct tracecmd_output *handle, struct buffer_instance *instance) > > +{ > > + char *str = NULL; > > + int len; > > + > > + len = asprintf(&str, "\nTraceID: %llu\n", instance->trace_id); > > + if (len < 1) > > + return; > > + tracecmd_add_option(handle, TRACECMD_OPTION_TRACEID, len + 1, str); > > + free(str); > > +} > > + > > static void > > add_buffer_stat(struct tracecmd_output *handle, struct buffer_instance *instance) > > { > > @@ -3817,6 +3830,8 @@ static void add_options(struct tracecmd_output *handle, struct common_record_con > > add_option_hooks(handle); > > add_uname(handle); > > add_version(handle); > > + if (!no_top_instance()) > > + add_trace_id(handle, &top_instance); > > } > > > > static void write_guest_file(struct buffer_instance *instance) > -- Tzvetomir (Ceco) Stoyanov VMware Open Source Technology Center