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 24A26C433ED for ; Thu, 15 Apr 2021 18:19:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E57AE611BF for ; Thu, 15 Apr 2021 18:19:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234620AbhDOSTm (ORCPT ); Thu, 15 Apr 2021 14:19:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234404AbhDOSTh (ORCPT ); Thu, 15 Apr 2021 14:19:37 -0400 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37B8CC06175F for ; Thu, 15 Apr 2021 11:19:13 -0700 (PDT) Received: by mail-ed1-x535.google.com with SMTP id o20so2939267edc.7 for ; Thu, 15 Apr 2021 11:19:13 -0700 (PDT) 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=PmecfFFFxrnk/yTNHYSDnpq8PX/J0+4kqxnhlh1oZFI=; b=QxzKKtjvTvdKQi2NrcGqTtAoY1Y2AnS2IfGSzBdwvkMAI2NAMF6EZ62OVXM6SmZFRH EbUrylkUnTvadK9RD48wey24hu0hNnj7Qe97GX3dJAGh8JoAn3DTvE6ngiNlFOHhVRcq A+dOqb4/1JtG9OwpzYuA1YjvcamVCSYJbw6y3A2IzgRMZA6tvVzdOzXTcJtM9ZJxz7Pa +Ed93NDcRKCuHtciJl7kNAQZWaiuEGL8gW6JbNc8EzV6A3ltDwx7pKiy2J+9a200Lzko yJ3gkYy3Iz+2bBKzmy5AjGAMGFDCl3H2zyngTYjGeBrZQyla+3OX4zBZPWME14kx9WUJ sJlQ== 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=PmecfFFFxrnk/yTNHYSDnpq8PX/J0+4kqxnhlh1oZFI=; b=Iau8v03Z/340lCAVaTwt8omzQHSJgTbLu67DXUuZit/5OkC7qgrfujOmeiWd0r72Lm 7vNOy9xSvDqLonMOV2nPc97zXWUvZvDBmQaMmLfSgNzrGHfvXg88P/v3LvQXBcQhZiK+ YEl6hGoj4x03IYj7IYyyfRzrlRGXKmphwUqI+XJVIqjvBLNkcy/Jz5aoUSUQomwZ4piJ jRBFv4Sj0zhA7FWOfOcxIpsjbM2I3GnyHE4K5GWxN3wfpJVEWruzoBdRSSuIQdREZXk6 Oa/Vc0MoYnuqF8Z0W4v64t2S5xfzePiNE1CT5Eu550ViGCEnefD1/4/LJpQBQNFStwDp H6Nw== X-Gm-Message-State: AOAM532a9yWeoc1sY5HDfDjBZ24NPiVaah/yHV0s1QEcjnCwlfyfzMiy TzJtNbhdn52DSPew3ofPUJM2H6OTQ6E= X-Google-Smtp-Source: ABdhPJzUFWvKSfpau3yBZTcykSRQ0OVAzTX42myBYFoIrnNN7H4r/Dsampj/o6kGRz5OkPmROTqiGw== X-Received: by 2002:aa7:dc15:: with SMTP id b21mr5857595edu.350.1618510751770; Thu, 15 Apr 2021 11:19:11 -0700 (PDT) Received: from localhost.localdomain ([84.40.93.55]) by smtp.gmail.com with ESMTPSA id h9sm1130903ejf.10.2021.04.15.11.19.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Apr 2021 11:19:11 -0700 (PDT) From: "Yordan Karadzhov (VMware)" To: linux-kernel@vger.kernel.org Cc: rostedt@goodmis.org, tglx@linutronix.de, peterz@infradead.org, "Yordan Karadzhov (VMware)" Subject: [PATCH v4 2/6] tracing: Define new ftrace event "func_repeats" Date: Thu, 15 Apr 2021 21:18:50 +0300 Message-Id: <20210415181854.147448-3-y.karadz@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210415181854.147448-1-y.karadz@gmail.com> References: <20210415181854.147448-1-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 | 22 +++++++++++++++++ kernel/trace/trace_output.c | 48 ++++++++++++++++++++++++++++++++++++ 3 files changed, 73 insertions(+) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 5506424eae2a..6a5b4c2a0fa7 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, }; @@ -442,6 +443,8 @@ 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..251c819cf0c5 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -338,3 +338,25 @@ FTRACE_ENTRY(hwlat, hwlat_entry, __entry->nmi_total_ts, __entry->nmi_count) ); + +#define FUNC_REPEATS_GET_DELTA_TS(entry) \ + (((u64)(entry)->top_delta_ts << 32) | (entry)->bottom_delta_ts) \ + +FTRACE_ENTRY(func_repeats, func_repeats_entry, + + TRACE_FUNC_REPEATS, + + F_STRUCT( + __field( unsigned long, ip ) + __field( unsigned long, parent_ip ) + __field( u16 , count ) + __field( u16 , top_delta_ts ) + __field( u32 , bottom_delta_ts ) + ), + + F_printk(" %ps <-%ps\t(repeats:%u delta: -%llu)", + (void *)__entry->ip, + (void *)__entry->parent_ip, + __entry->count, + FUNC_REPEATS_GET_DELTA_TS(__entry)) +); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 333233d45596..3037f0c88f90 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1381,6 +1381,53 @@ 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 %u %llu\n", + field->ip, + field->parent_ip, + field->count, + FUNC_REPEATS_GET_DELTA_TS(field)); + + 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->parent_ip, flags); + trace_seq_printf(s, " (repeats: %u, last_ts:", field->count); + trace_print_time(s, iter, + iter->ts - FUNC_REPEATS_GET_DELTA_TS(field)); + trace_seq_puts(s, ")\n"); + + 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, @@ -1393,6 +1440,7 @@ static struct trace_event *events[] __initdata = { &trace_print_event, &trace_hwlat_event, &trace_raw_data_event, + &trace_func_repeats_event, NULL }; -- 2.25.1