| libtracefs(3) |
| ============= |
| |
| NAME |
| ---- |
| tracefs_hist_start, tracefs_hist_destroy, tracefs_hist_pause, |
| tracefs_hist_continue, tracefs_hist_reset - Pause, continue, or clear an existing histogram |
| |
| SYNOPSIS |
| -------- |
| [verse] |
| -- |
| *#include <tracefs.h>* |
| |
| int *tracefs_hist_start*(struct tracefs_instance pass:[*]_instance_, struct tracefs_hist pass:[*]_hist_); |
| int *tracefs_hist_destroy*(struct tracefs_instance pass:[*]_instance_, struct tracefs_hist pass:[*]_hist_); |
| int *tracefs_hist_pause*(struct tracefs_instance pass:[*]_instance_, struct tracefs_hist pass:[*]_hist_); |
| int *tracefs_hist_continue*(struct tracefs_instance pass:[*]_instance_, struct tracefs_hist pass:[*]_hist_); |
| int *tracefs_hist_reset*(struct tracefs_instance pass:[*]_instance_, struct tracefs_hist pass:[*]_hist_); |
| |
| -- |
| |
| DESCRIPTION |
| ----------- |
| |
| *tracefs_hist_start()* is called to actually start the histogram _hist_. |
| The _instance_ is the instance to start the histogram in, NULL if it |
| should start at the top level. |
| |
| *tracefs_hist_pause()* is called to pause the histogram _hist_. |
| The _instance_ is the instance to pause the histogram in, NULL if it |
| is in the top level. |
| |
| *tracefs_hist_continue()* is called to continue a paused histogram _hist_. |
| The _instance_ is the instance to continue the histogram, NULL if it |
| is in the top level. |
| |
| *tracefs_hist_reset()* is called to clear / reset the histogram _hist_. |
| The _instance_ is the instance to clear the histogram, NULL if it |
| is in the top level. |
| |
| *tracefs_hist_destroy()* is called to delete the histogram where it will no longer |
| exist. The _instance_ is the instance to delete the histogram from, NULL if it |
| is in the top level. |
| |
| RETURN VALUE |
| ------------ |
| All the return zero on success or -1 on error. |
| |
| EXAMPLE |
| ------- |
| [source,c] |
| -- |
| #include <stdlib.h> |
| #include <tracefs.h> |
| |
| enum commands { |
| START, |
| PAUSE, |
| CONT, |
| RESET, |
| DELETE, |
| SHOW, |
| }; |
| |
| int main (int argc, char **argv, char **env) |
| { |
| struct tracefs_instance *instance; |
| struct tracefs_hist *hist; |
| struct tep_handle *tep; |
| enum commands cmd; |
| char *cmd_str; |
| int ret; |
| |
| if (argc < 2) { |
| fprintf(stderr, "usage: %s command\n", argv[0]); |
| exit(-1); |
| } |
| |
| cmd_str = argv[1]; |
| |
| if (!strcmp(cmd_str, "start")) |
| cmd = START; |
| else if (!strcmp(cmd_str, "pause")) |
| cmd = PAUSE; |
| else if (!strcmp(cmd_str, "cont")) |
| cmd = CONT; |
| else if (!strcmp(cmd_str, "reset")) |
| cmd = RESET; |
| else if (!strcmp(cmd_str, "delete")) |
| cmd = DELETE; |
| else if (!strcmp(cmd_str, "show")) |
| cmd = SHOW; |
| else { |
| fprintf(stderr, "Unknown command %s\n", cmd_str); |
| exit(-1); |
| } |
| |
| tep = tracefs_local_events(NULL); |
| if (!tep) { |
| perror("Reading tracefs"); |
| exit(-1); |
| } |
| |
| instance = tracefs_instance_create("hist_test"); |
| if (!instance) { |
| fprintf(stderr, "Failed instance create\n"); |
| exit(-1); |
| } |
| |
| hist = tracefs_hist_alloc_2d(tep, "kmem", "kmalloc", |
| "call_site",TRACEFS_HIST_KEY_SYM, |
| "bytes_req", 0); |
| if (!hist) { |
| fprintf(stderr, "Failed hist create\n"); |
| exit(-1); |
| } |
| |
| ret = tracefs_hist_add_value(hist, "bytes_alloc"); |
| ret |= tracefs_hist_add_sort_key(hist, "bytes_req"); |
| ret |= tracefs_hist_add_sort_key(hist, "bytes_alloc"); |
| |
| ret |= tracefs_hist_sort_key_direction(hist, "bytes_alloc", |
| TRACEFS_HIST_SORT_DESCENDING); |
| if (ret) { |
| fprintf(stderr, "Failed modifying histogram\n"); |
| exit(-1); |
| } |
| |
| tracefs_error_clear(instance); |
| |
| switch (cmd) { |
| case START: |
| ret = tracefs_hist_start(instance, hist); |
| if (ret) { |
| char *err = tracefs_error_last(instance); |
| if (err) |
| fprintf(stderr, "\n%s\n", err); |
| } |
| break; |
| case PAUSE: |
| ret = tracefs_hist_pause(instance, hist); |
| break; |
| case CONT: |
| ret = tracefs_hist_continue(instance, hist); |
| break; |
| case RESET: |
| ret = tracefs_hist_reset(instance, hist); |
| break; |
| case DELETE: |
| ret = tracefs_hist_destroy(instance, hist); |
| break; |
| case SHOW: { |
| char *content; |
| content = tracefs_event_file_read(instance, "kmem", "kmalloc", |
| "hist", NULL); |
| ret = content ? 0 : -1; |
| if (content) { |
| printf("%s\n", content); |
| free(content); |
| } |
| break; |
| } |
| } |
| if (ret) |
| fprintf(stderr, "Failed: command\n"); |
| exit(ret); |
| } |
| |
| -- |
| |
| FILES |
| ----- |
| [verse] |
| -- |
| *tracefs.h* |
| Header file to include in order to have access to the library APIs. |
| *-ltracefs* |
| Linker switch to add when building a program that uses the library. |
| -- |
| |
| SEE ALSO |
| -------- |
| *libtracefs*(3), |
| *libtraceevent*(3), |
| *trace-cmd*(1), |
| *tracefs_hist_alloc*(3), |
| *tracefs_hist_alloc_2d*(3), |
| *tracefs_hist_alloc_nd*(3), |
| *tracefs_hist_free*(3), |
| *tracefs_hist_add_key*(3), |
| *tracefs_hist_add_value*(3), |
| *tracefs_hist_add_name*(3), |
| *tracefs_hist_start*(3), |
| *tracefs_hist_destory*(3), |
| *tracefs_hist_add_sort_key*(3), |
| *tracefs_hist_sort_key_direction*(3) |
| |
| AUTHOR |
| ------ |
| [verse] |
| -- |
| *Steven Rostedt* <rostedt@goodmis.org> |
| *Tzvetomir Stoyanov* <tz.stoyanov@gmail.com> |
| *sameeruddin shaik* <sameeruddin.shaik8@gmail.com> |
| -- |
| REPORTING BUGS |
| -------------- |
| Report bugs to <linux-trace-devel@vger.kernel.org> |
| |
| LICENSE |
| ------- |
| libtracefs is Free Software licensed under the GNU LGPL 2.1 |
| |
| RESOURCES |
| --------- |
| https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/ |
| |
| COPYING |
| ------- |
| Copyright \(C) 2020 VMware, Inc. Free use of this software is granted under |
| the terms of the GNU Public License (GPL). |