Re: [PATCH 10/22] tools lib traceevent: Add function plugin
From: Namhyung Kim
Date: Fri Nov 22 2013 - 10:04:03 EST
2013-11-21 (ë), 12:01 +0100, Jiri Olsa:
> Backporting function plugin.
>
> Backported from Steven Rostedt's trace-cmd repo (HEAD 0f2c2fb):
> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
>
> This plugin adds function and parent function fields
> resolving for ftrace:function tracepoint event.
>
> The diff of 'perf script' output generated by old and new code:
> (data was generated by 'perf record -e ftrace:function ls')
>
> --- script.function.old
> +++ script.function.new
> - ls 10781 [001] 32667.291379: ftrace:function: ffffffff811adb80 <-- ffffffff811afc48
> - ls 10781 [001] 32667.291379: ftrace:function: ffffffff811b35d0 <-- ffffffff811adb9b
> - ls 10781 [001] 32667.291380: ftrace:function: ffffffff811b3520 <-- ffffffff811b35e8
> - ls 10781 [001] 32667.291380: ftrace:function: ffffffff811b2720 <-- ffffffff811b3549
> - ls 10781 [001] 32667.291381: ftrace:function: ffffffff81297e10 <-- ffffffff811b356c
> - ls 10781 [001] 32667.291381: ftrace:function: ffffffff81298f40 <-- ffffffff81297e2c
> - ls 10781 [001] 32667.291382: ftrace:function: ffffffff81076160 <-- ffffffff811afbf0
> - ls 10781 [001] 32667.291383: ftrace:function: ffffffff811c3eb0 <-- ffffffff811afbfc
> - ls 10781 [001] 32667.291383: ftrace:function: ffffffff8164e100 <-- ffffffff811c3ed8
> - ls 10781 [001] 32667.291384: ftrace:function: ffffffff811a5d10 <-- ffffffff811c3f53
> - ls 10781 [001] 32667.291384: ftrace:function: ffffffff811e8e70 <-- ffffffff811a5d58
> - ls 10781 [001] 32667.291385: ftrace:function: ffffffff811f38e0 <-- ffffffff811a5d63
> - ls 10781 [001] 32667.291385: ftrace:function: ffffffff811a9ff0 <-- ffffffff811a5d6b
> - ls 10781 [001] 32667.291386: ftrace:function: ffffffff811a9fa0 <-- ffffffff811aa015
> - ls 10781 [001] 32667.291387: ftrace:function: ffffffff810851c0 <-- ffffffff811aa053
> - ls 10781 [001] 32667.291387: ftrace:function: ffffffff81090e00 <-- ffffffff81085211
> + ls 10781 [001] 32667.291379: ftrace:function: would_dump <-- setup_new_exec
> + ls 10781 [001] 32667.291379: ftrace:function: inode_permission <-- would_dump
> + ls 10781 [001] 32667.291380: ftrace:function: __inode_permission <-- inode_permission
> + ls 10781 [001] 32667.291380: ftrace:function: generic_permission <-- __inode_permission
> + ls 10781 [001] 32667.291381: ftrace:function: security_inode_permission <-- __inode_permission
> + ls 10781 [001] 32667.291381: ftrace:function: cap_inode_permission <-- security_inode_permission
> + ls 10781 [001] 32667.291382: ftrace:function: flush_signal_handlers <-- setup_new_exec
> + ls 10781 [001] 32667.291383: ftrace:function: do_close_on_exec <-- setup_new_exec
> + ls 10781 [001] 32667.291383: ftrace:function: _raw_spin_lock <-- do_close_on_exec
> + ls 10781 [001] 32667.291384: ftrace:function: filp_close <-- do_close_on_exec
> + ls 10781 [001] 32667.291384: ftrace:function: dnotify_flush <-- filp_close
> + ls 10781 [001] 32667.291385: ftrace:function: locks_remove_posix <-- filp_close
> + ls 10781 [001] 32667.291385: ftrace:function: fput <-- filp_close
> + ls 10781 [001] 32667.291386: ftrace:function: file_sb_list_del <-- fput
> + ls 10781 [001] 32667.291387: ftrace:function: task_work_add <-- fput
> + ls 10781 [001] 32667.291387: ftrace:function: kick_process <-- task_work_add
>
> Removing options support as it's not backported yet.
> Currently this plugin supports 2 options:
> 'parent' to display parent function
> 'indent' to show function call indents
>
> Enabling both of them by default.
[SNIP]
> +static struct func_stack {
> + int index;
It seems not used anywhere.
> + int size;
> + char **stack;
> +} *fstack;
> +
> +static int cpus = -1;
> +
> +#define STK_BLK 10
> +
> +static void add_child(struct func_stack *stack, const char *child, int pos)
> +{
> + int i;
> +
> + if (!child)
> + return;
> +
> + if (pos < stack->size)
> + free(stack->stack[pos]);
> + else {
> + if (!stack->stack)
> + stack->stack = malloc_or_die(sizeof(char *) * STK_BLK);
Please do not use this function.
> + else
> + stack->stack = realloc(stack->stack, sizeof(char *) *
> + (stack->size + STK_BLK));
It seems you need to use a local variable to check return value.
> + for (i = stack->size; i < stack->size + STK_BLK; i++)
> + stack->stack[i] = NULL;
> + stack->size += STK_BLK;
> + }
> +
> + stack->stack[pos] = strdup(child);
> +}
> +
> +static int get_index(const char *parent, const char *child, int cpu)
It seems this function does not only to get index but also to add
function stack. So how about renaming it to something like
add_and_get_index()?
> +{
> + int i;
> +
> + if (cpu < 0)
> + return 0;
> +
> + if (cpu > cpus) {
> + if (fstack)
> + fstack = realloc(fstack, sizeof(*fstack) * (cpu + 1));
> + else
> + fstack = malloc_or_die(sizeof(*fstack) * (cpu + 1));
It seems it has same problem as above function.
> +
> + /* Account for holes in the cpu count */
> + for (i = cpus + 1; i <= cpu; i++)
> + memset(&fstack[i], 0, sizeof(fstack[i]));
> + cpus = cpu;
> + }
> +
> + for (i = 0; i < fstack[cpu].size && fstack[cpu].stack[i]; i++) {
> + if (strcmp(parent, fstack[cpu].stack[i]) == 0) {
> + add_child(&fstack[cpu], child, i+1);
> + return i;
> + }
> + }
> +
> + /* Not found */
> + add_child(&fstack[cpu], parent, 0);
> + add_child(&fstack[cpu], child, 1);
> + return 0;
> +}
> +
> +static int function_handler(struct trace_seq *s, struct pevent_record *record,
> + struct event_format *event, void *context)
> +{
> + struct pevent *pevent = event->pevent;
> + unsigned long long function;
> + unsigned long long pfunction;
> + const char *func;
> + const char *parent;
> + int i, index;
> +
> + if (pevent_get_field_val(s, event, "ip", record, &function, 1))
> + return trace_seq_putc(s, '!');
> +
> + func = pevent_find_function(pevent, function);
> +
> + if (pevent_get_field_val(s, event, "parent_ip", record, &pfunction, 1))
> + return trace_seq_putc(s, '!');
> +
> + parent = pevent_find_function(pevent, pfunction);
> +
> + index = get_index(parent, func, record->cpu);
> +
> + for (i = 0; i < index; i++)
> + trace_seq_printf(s, " ");
What about this?
trace_seq_printf(s, "%*s", index*3, "");
Thanks,
Namhyung
> +
> + if (func)
> + trace_seq_printf(s, "%s", func);
> + else
> + trace_seq_printf(s, "0x%llx", function);
> +
> + trace_seq_printf(s, " <-- ");
> + if (parent)
> + trace_seq_printf(s, "%s", parent);
> + else
> + trace_seq_printf(s, "0x%llx", pfunction);
> +
> + return 0;
> +}
> +
> +int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
> +{
> + pevent_register_event_handler(pevent, -1, "ftrace", "function",
> + function_handler, NULL);
> + return 0;
> +}
> +
> +void PEVENT_PLUGIN_UNLOADER(void)
> +{
> + int i, x;
> +
> + for (i = 0; i <= cpus; i++) {
> + for (x = 0; x < fstack[i].size && fstack[i].stack[x]; x++)
> + free(fstack[i].stack[x]);
> + free(fstack[i].stack);
> + }
> +
> + free(fstack);
> + fstack = NULL;
> + cpus = -1;
> +}
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