Re: [PATCH 3/6] kernel-shark-qt: Add an example showing how to manipulate the Vis. model.

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 11 Jul 2018 16:38:11 +0300
"Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:

> This patch introduces a basic example, showing how to initialize the
> Visualization model and to use the API to perform some of the basic
> operations.
> 
> Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
> ---
>  kernel-shark-qt/examples/CMakeLists.txt |   4 +
>  kernel-shark-qt/examples/datahisto.c    | 155 ++++++++++++++++++++++++
>  2 files changed, 159 insertions(+)
>  create mode 100644 kernel-shark-qt/examples/datahisto.c
> 
> diff --git a/kernel-shark-qt/examples/CMakeLists.txt b/kernel-shark-qt/examples/CMakeLists.txt
> index 009fd1e..6906eba 100644
> --- a/kernel-shark-qt/examples/CMakeLists.txt
> +++ b/kernel-shark-qt/examples/CMakeLists.txt
> @@ -7,3 +7,7 @@ target_link_libraries(dload   kshark)
>  message(STATUS "datafilter")
>  add_executable(dfilter          datafilter.c)
>  target_link_libraries(dfilter   kshark)
> +
> +message(STATUS "datahisto")
> +add_executable(dhisto          datahisto.c)
> +target_link_libraries(dhisto   kshark)
> diff --git a/kernel-shark-qt/examples/datahisto.c b/kernel-shark-qt/examples/datahisto.c
> new file mode 100644
> index 0000000..1db2b02
> --- /dev/null
> +++ b/kernel-shark-qt/examples/datahisto.c
> @@ -0,0 +1,155 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * Copyright (C) 2018 VMware Inc, Yordan Karadzhov <y.karadz@gmail.com>
> + */
> +
> +// C
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +// KernelShark
> +#include "libkshark.h"
> +#include "libkshark-model.h"
> +
> +#define N_BINS 5
> +
> +const char *default_file = "trace.dat";
> +
> +void dump_bin(struct kshark_trace_histo *histo, int bin,
> +	      const char *type, int val)
> +{
> +	const struct kshark_entry *e_front, *e_back;
> +	char *entry_str;
> +	ssize_t i_front, i_back;
> +
> +	printf("bin %i {\n", bin);
> +	if (strcmp(type, "cpu") == 0) {
> +		e_front = ksmodel_get_entry_front(histo, bin, true,
> +						  kshark_check_cpu, val,
> +						  &i_front);
> +
> +		e_back = ksmodel_get_entry_back(histo, bin, true,
> +						kshark_check_cpu, val,
> +						&i_back);
> +	} else if (strcmp(type, "task") == 0) {
> +		e_front = ksmodel_get_entry_front(histo, bin, true,
> +						  kshark_check_pid, val,
> +						  &i_front);
> +
> +		e_back = ksmodel_get_entry_back(histo, bin, true,
> +						kshark_check_pid, val,

Yeah, I think we need to rename the functions to:

 kshark_match_cpu() and kshark_match_pid()


> +						&i_back);
> +	} else {
> +		i_front = ksmodel_first_index_at_bin(histo, bin);
> +		e_front = histo->data[i_front];
> +
> +		i_back = ksmodel_last_index_at_bin(histo, bin);
> +		e_back = histo->data[i_back];
> +	}
> +
> +	if (i_front == KS_EMPTY_BIN) {
> +		puts ("EMPTY BIN");
> +	} else {
> +		entry_str = kshark_dump_entry(e_front);
> +		printf("%li -> %s\n", i_front, entry_str);
> +		free(entry_str);
> +
> +		entry_str = kshark_dump_entry(e_back);
> +		printf("%li -> %s\n", i_back, entry_str);
> +		free(entry_str);
> +	}
> +
> +	puts("}\n");
> +}
> +
> +void dump_histo(struct kshark_trace_histo *histo, const char *type, int val)
> +{
> +	size_t bin;
> +
> +	for (bin = 0; bin < histo->n_bins; ++bin)
> +		dump_bin(histo, bin, type, val);
> +}
> +
> +int main(int argc, char **argv)
> +{
> +	struct kshark_context *kshark_ctx;
> +	struct kshark_entry **data = NULL;
> +	struct kshark_trace_histo histo;
> +	size_t i, n_rows, n_tasks;
> +	bool status;
> +	int *pids;

See how nice the upside-down-xmas tree format looks :-)

The rest of this patch looks fine.

-- Steve

> +
> +	/* 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);
> +
> +	/* Get a list of all tasks. */
> +	n_tasks = kshark_get_task_pids(kshark_ctx, &pids);
> +
> +	/* Initialize the Visualization Model. */
> +	ksmodel_init(&histo);
> +	ksmodel_set_bining(&histo, N_BINS, data[0]->ts,
> +					   data[n_rows - 1]->ts);
> +
> +	/* Fill the model with data and calculate its state. */
> +	ksmodel_fill(&histo, data, n_rows);
> +
> +	/* Dump the raw bins. */
> +	dump_histo(&histo, "", 0);
> +
> +	puts("\n...\n\n");
> +
> +	/*
> +	 * Change the state of the model. Do 50% Zoom-In and dump only CPU 0.
> +	 */
> +	ksmodel_zoom_in(&histo, .50, -1);
> +	dump_histo(&histo, "cpu", 0);
> +
> +	puts("\n...\n\n");
> +
> +	/* Shift forward by two bins and this time dump only CPU 1. */
> +	ksmodel_shift_forward(&histo, 2);
> +	dump_histo(&histo, "cpu", 1);
> +
> +	puts("\n...\n\n");
> +
> +	/*
> +	 * Do 10% Zoom-Out, using the last bin as a focal point. Dump the last
> +	 * Task.
> +	 */
> +	ksmodel_zoom_out(&histo, .10, N_BINS - 1);
> +	dump_histo(&histo, "task", pids[n_tasks - 1]);
> +
> +	/* Reset (clear) the model. */
> +	ksmodel_clear(&histo);
> +
> +	/* 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;
> +}