From patchwork Mon Jul 2 14:04:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yordan Karadzhov X-Patchwork-Id: 10758635 Return-Path: Received: from mail-wm0-f68.google.com ([74.125.82.68]:39154 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752320AbeGBOFJ (ORCPT ); Mon, 2 Jul 2018 10:05:09 -0400 Received: by mail-wm0-f68.google.com with SMTP id p11-v6so8839366wmc.4 for ; Mon, 02 Jul 2018 07:05:09 -0700 (PDT) From: "Yordan Karadzhov (VMware)" To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org, "Yordan Karadzhov (VMware)" Subject: [PATCH v4 7/9] kernel-shark-qt: Add an example showing how to filter trace data Date: Mon, 2 Jul 2018 17:04:22 +0300 Message-Id: <20180702140424.23221-7-y.karadz@gmail.com> In-Reply-To: <20180702140424.23221-1-y.karadz@gmail.com> References: <20180702140424.23221-1-y.karadz@gmail.com> Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 3860 This patch introduces a basic example, showing how to use the C API of KernelShark in order to filter trace data. Signed-off-by: Yordan Karadzhov (VMware) --- kernel-shark-qt/examples/CMakeLists.txt | 4 + kernel-shark-qt/examples/datafilter.c | 124 ++++++++++++++++++++++++ 2 files changed, 128 insertions(+) create mode 100644 kernel-shark-qt/examples/datafilter.c diff --git a/kernel-shark-qt/examples/CMakeLists.txt b/kernel-shark-qt/examples/CMakeLists.txt index 98df9d8..009fd1e 100644 --- a/kernel-shark-qt/examples/CMakeLists.txt +++ b/kernel-shark-qt/examples/CMakeLists.txt @@ -3,3 +3,7 @@ message("\n examples ...") message(STATUS "dataload") add_executable(dload dataload.c) target_link_libraries(dload kshark) + +message(STATUS "datafilter") +add_executable(dfilter datafilter.c) +target_link_libraries(dfilter kshark) diff --git a/kernel-shark-qt/examples/datafilter.c b/kernel-shark-qt/examples/datafilter.c new file mode 100644 index 0000000..e2039ca --- /dev/null +++ b/kernel-shark-qt/examples/datafilter.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2018 VMware Inc, Yordan Karadzhov + */ + +// C +#include +#include + +// KernelShark +#include "libkshark.h" + +const char *default_file = "trace.dat"; + +int main(int argc, char **argv) +{ + size_t i, n_rows, n_tasks, n_evts, count; + struct kshark_context *kshark_ctx; + struct kshark_entry **data = NULL; + char *entry_str; + bool status; + int *pids; + + /* Create a new kshark session. */ + kshark_ctx = NULL; + if (!kshark_instance(&kshark_ctx)) + return 1; + + /* Open a trace data file produced by trace-cmd. */ + if (argc > 1) + status = kshark_open(kshark_ctx, argv[1]); + else + status = kshark_open(kshark_ctx, default_file); + + if (!status) { + kshark_free(kshark_ctx); + return 1; + } + + /* Load the content of the file into an array of entries. */ + n_rows = kshark_load_data_entries(kshark_ctx, &data); + + /* Filter the trace data coming from trace-cmd. */ + n_tasks = kshark_get_task_pids(kshark_ctx, &pids); + for (i = 0; i < n_tasks; ++i) { + const char *task_str = + pevent_data_comm_from_pid(kshark_ctx->pevent, + pids[i]); + + if (strcmp(task_str, "trace-cmd") == 0) + kshark_filter_add_id(kshark_ctx, KS_HIDE_TASK_FILTER, + pids[i]); + } + + free(pids); + + /* + * Set the Filter Mask. In this case we want to avoid showing the + * filterd entris in text format. + */ + kshark_ctx->filter_mask = KS_TEXT_VIEW_FILTER_MASK; + kshark_filter_entries(kshark_ctx, data, n_rows); + + /* Print to the screen the first 10 visible entries. */ + count = 0; + i = 0; + for (i = 0; i < n_rows; ++i) { + if (data[i]->visible & KS_TEXT_VIEW_FILTER_MASK) { + entry_str = kshark_dump_entry(data[i]); + puts(entry_str); + free(entry_str); + + if (++count > 10) + break; + } + + ++i; + } + + puts("\n\n"); + + /* Show only "sched" events. */ + struct event_format *event; + n_evts = kshark_ctx->pevent->nr_events; + for (i = 0; i < n_evts; ++i) { + event = kshark_ctx->pevent->events[i]; + if (strcmp(event->system, "sched") == 0) + kshark_filter_add_id(kshark_ctx, KS_SHOW_EVENT_FILTER, + event->id); + } + + kshark_filter_entries(kshark_ctx, data, n_rows); + + /* Print to the screen the first 10 visible entries. */ + count = 0; + i = 0; + for (i = 0; i < n_rows; ++i) { + if (data[i]->visible & KS_TEXT_VIEW_FILTER_MASK) { + entry_str = kshark_dump_entry(data[i]); + puts(entry_str); + free(entry_str); + + if (++count > 10) + break; + } + + ++i; + } + + /* Free the memory. */ + for (i = 0; i < n_rows; ++i) + free(data[i]); + + free(data); + + /* Close the file. */ + kshark_close(kshark_ctx); + + /* Close the session. */ + kshark_free(kshark_ctx); + + return 0; +}