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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 0ED1FC433E0 for ; Thu, 4 Mar 2021 09:04:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1E0864F18 for ; Thu, 4 Mar 2021 09:04:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237140AbhCDJDa (ORCPT ); Thu, 4 Mar 2021 04:03:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237115AbhCDJDA (ORCPT ); Thu, 4 Mar 2021 04:03:00 -0500 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACF98C061760 for ; Thu, 4 Mar 2021 01:02:19 -0800 (PST) Received: by mail-ej1-x62b.google.com with SMTP id do6so47918758ejc.3 for ; Thu, 04 Mar 2021 01:02:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=GH5i/Doj3qYar7VrbSA66dTewYhBnt7d/9ntJ1/mTDo=; b=o4/pU1awgdPYGCdfBJiJH6+HRw8aW0sL+sykk1LzvXD1WZYKENfVCQ/aABA1kSvkPI H9bJmhgzdT5DIURLap7Px7gC26GfVhQEznWht5GOEvITuFpdFy8tKMailc32OYnSvLhV OG4jF3xCKkRmjalS4+E6ipIoex68kU6uH8RrAW/H/nfUXLWTe/XjV+YsvfSxUnA4+Yul 03QLKwcBRpkySkcHbotS9YYqtNLizdifuJSz+DFEbXWUaAsL0H9LEKrQtCts6Xu3wN+7 nzplqZZf6LhwtxgCnt317m0sGRRpFQvAltc+J/56coFXXm4AqmLelWhYfiwGlF1tj+f3 2xXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=GH5i/Doj3qYar7VrbSA66dTewYhBnt7d/9ntJ1/mTDo=; b=bxoDtPGtlv5+PI29rCed8/zfkl7oF+wO6syfh+PjIN2iT88J1rnMZGaA9oT/sUXLLH V/ptIjEPm1rQtVNaPOahr7ComiKtjLIlrlsoSaNPBGSbI1lPqUdgwWOwEe12VVKrc5MV TdiHKMmoBCNu3EPJrFRcZieajmLHiduFxvBHkzlEOJFOH1bjfU0pwOhaDHsC6ItNx/kH shcStu+VV/2NjkULEDFRnDal89kD8oCzyD2as9jrs/Wz4a+VULRTlLb14I1Faytk4gzj zBY1jb0z1fewCzbDefsnWc47EoTjCbNQtnipbBkBi6CJHXamDNlmkNpcKwkEecZN09qG dtgA== X-Gm-Message-State: AOAM533Kk8aBVSBYieLSY/NAgui/BnigMi1V+VpIeS3vRfXFeG0KYj3l O3XuRTQGcwrfWTy/LSJKrB9Sj6zMy9vB3g== X-Google-Smtp-Source: ABdhPJzdqev3Of4xN2Do9C+6XxwlKVaQOlAM93/fLGEXTsVOcQM86v0FJfe0r58rDpj5S+Ahn31TrQ== X-Received: by 2002:a17:906:4f96:: with SMTP id o22mr3022835eju.511.1614848538242; Thu, 04 Mar 2021 01:02:18 -0800 (PST) Received: from localhost.localdomain ([95.87.199.88]) by smtp.gmail.com with ESMTPSA id f22sm23123552eje.34.2021.03.04.01.02.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Mar 2021 01:02:17 -0800 (PST) From: "Yordan Karadzhov (VMware)" To: linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, "Yordan Karadzhov (VMware)" Subject: [RFC PATCH 1/5] tracing: Define new ftrace event "func_repeats" Date: Thu, 4 Mar 2021 11:01:37 +0200 Message-Id: <20210304090141.207309-2-y.karadz@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210304090141.207309-1-y.karadz@gmail.com> References: <20210304090141.207309-1-y.karadz@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The event aims to consolidate the function tracing record in the cases when a single function is called number of times consecutively. while (cond) do_func(); This may happen in various scenarios (busy waiting for example). The new ftrace event can be used to show repeated function events with a single event and save space on the ring buffer Signed-off-by: Yordan Karadzhov (VMware) --- kernel/trace/trace.h | 3 +++ kernel/trace/trace_entries.h | 16 +++++++++++++ kernel/trace/trace_output.c | 44 ++++++++++++++++++++++++++++++++++++ 3 files changed, 63 insertions(+) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index a6446c03cfbc..2be4a56879de 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -45,6 +45,7 @@ enum trace_type { TRACE_BPUTS, TRACE_HWLAT, TRACE_RAW_DATA, + TRACE_FUNC_REPEATS, __TRACE_LAST_TYPE, }; @@ -441,6 +442,8 @@ extern void __ftrace_bad_type(void); TRACE_GRAPH_ENT); \ IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ TRACE_GRAPH_RET); \ + IF_ASSIGN(var, ent, struct func_repeats_entry, \ + TRACE_FUNC_REPEATS); \ __ftrace_bad_type(); \ } while (0) diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index 4547ac59da61..8007f9b6417f 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -338,3 +338,19 @@ FTRACE_ENTRY(hwlat, hwlat_entry, __entry->nmi_total_ts, __entry->nmi_count) ); + +FTRACE_ENTRY(func_repeats, func_repeats_entry, + + TRACE_FUNC_REPEATS, + + F_STRUCT( + __field( unsigned long, ip ) + __field( unsigned long, pip ) + __field( unsigned long, count ) + ), + + F_printk(" %ps <-%ps\t(repeats:%lu)", + (void *)__entry->ip, + (void *)__entry->pip, + __entry->count) +); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 61255bad7e01..af6b066972e9 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1373,6 +1373,49 @@ static struct trace_event trace_raw_data_event = { .funcs = &trace_raw_data_funcs, }; +static enum print_line_t +trace_func_repeats_raw(struct trace_iterator *iter, int flags, + struct trace_event *event) +{ + struct func_repeats_entry *field; + struct trace_seq *s = &iter->seq; + + trace_assign_type(field, iter->ent); + + trace_seq_printf(s, "%lu %lu %li\n", + field->pip, + field->ip, + field->count); + + return trace_handle_return(s); +} + +static enum print_line_t +trace_func_repeats_print(struct trace_iterator *iter, int flags, + struct trace_event *event) +{ + struct func_repeats_entry *field; + struct trace_seq *s = &iter->seq; + + trace_assign_type(field, iter->ent); + + seq_print_ip_sym(s, field->ip, flags); + trace_seq_puts(s, " <-"); + seq_print_ip_sym(s, field->pip, flags); + trace_seq_printf(s, " (repeats: %li)\n", field->count); + + return trace_handle_return(s); +} + +static struct trace_event_functions trace_func_repeats_funcs = { + .trace = trace_func_repeats_print, + .raw = trace_func_repeats_raw, +}; + +static struct trace_event trace_func_repeats_event = { + .type = TRACE_FUNC_REPEATS, + .funcs = &trace_func_repeats_funcs, +}; static struct trace_event *events[] __initdata = { &trace_fn_event, @@ -1385,6 +1428,7 @@ static struct trace_event *events[] __initdata = { &trace_print_event, &trace_hwlat_event, &trace_raw_data_event, + &trace_func_repeats_event, NULL }; -- 2.25.1