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Date: Thu, 15 Mar 2018 11:12:15 +0800
From: "Jin, Yao" <yao.jin@...ux.intel.com>
To: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: jolsa@...nel.org, peterz@...radead.org, mingo@...hat.com,
alexander.shishkin@...ux.intel.com, Linux-kernel@...r.kernel.org,
ak@...ux.intel.com, kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v1 0/4] perf annotate: Create a new '--tui-dump' option
On 3/14/2018 9:54 PM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Mar 14, 2018 at 10:04:49AM +0800, Jin, Yao escreveu:
>>
>>
>> On 3/13/2018 11:20 PM, Arnaldo Carvalho de Melo wrote:
>>> Em Tue, Mar 13, 2018 at 10:16:50PM +0800, Jin Yao escreveu:
>>>> There is a requirement to let perf annotate support displaying the IPC/Cycle.
>>>> In previous patch, this is supported in TUI mode. While it's not convenient
>>>> for users since they have to take screen shots and copy/paste data.
>>>>
>>>> This patch series introduces a new option '--tui-dump' in perf annotate to
>>>> dump the TUI output to stdio.
>>>>
>>>> User can easily use the command line like:
>>>> 'perf annotate --tui-dump > /tmp/log.txt'
>>>
>>> My first impression is that this pollutes the code with way too many
>>> ifs, I was thinking more of a:
>>>
>>> while (read parsed objdump line) {
>>> ins__fprintf();
>>> }
>>>
>>
>> Yes, the issue in my patch is that it uses many 'if' to check if it's
>> tui_dump(or called 'stdio2') or tui mode.
>>
>>> Going from the refresh routine, I started doing the conversion, but haven't
>>> completed it, there are opportunities for more __scnprintf like routines, also
>>> one to find the percent_max, etc then those would be used both in these two for
>>> --stdio2, that eventually would become --stdio with the old one becoming
>>> --stdio1, till we're satisfied with the new default.
>>>
>>
>> I have some questions for the following code. Please correct me if I
>> misunderstand anything.
>>
>>> static void annotation_line__fprintf(struct annotate_line *al, FILE *fp)
>>> {
>>> struct browser_line *bl = browser_line(al);
>>> int i;
>>> double percent_max = 0.0;
>>> char bf[256];
>>>
>>> for (i = 0; i < browser->nr_events; i++) {
>>> if (al->samples[i].percent > percent_max)
>>> percent_max = al->samples[i].percent;
>>> }
>>>
>>> /* the following if/else block should be transformed into a __scnprintf routine
>>> that formats a buffer and then the TUI and --stdio2 use it */
>>>
>>> if (al->offset != -1 && percent_max != 0.0) {
>>> for (i = 0; i < ab->nr_events; i++) {
>>> if (annotate_browser__opts.show_total_period) {
>>> fprintf(fp, browser, "%11" PRIu64 " ", al->samples[i].he.period);
>>> } else if (annotate_browser__opts.show_nr_samples) {
>>> fprintf(fp, browser, "%6" PRIu64 " ", al->samples[i].he.nr_samples);
>>> } else {
>>> fprintf(fp, "%6.2f ", al->samples[i].percent);
>>> }
>>> }
>>> } else {
>>> ui_browser__printf(browser, "%*s", pcnt_width,
>>> annotate_browser__opts.show_total_period ? "Period" :
>>> annotate_browser__opts.show_nr_samples ? "Samples" : "Percent");
>>>
>>> }
>>>
>>
>> I guess the above code has not been completed yet. My understanding for
>> Arnaldo's idea is that the output should be written to a buffer via
>> scnprintf and the buffer will be passed to TUI or stdio2 and printed out
>> later.
>>
>> One potential issue is how to process the color for TUI? For example, the
>> call to ui_browser__set_percent_color. If we need to set color for TUI, it
>> looks we still have to check if it's a TUI mode.
>
> That is part of the uncompleted code, if you want to show colors in
> --stdio2 (and I think it is worth) then use color_fprintf() like other
> stdio code.
>
> For instance, 'perf top --stdio' uses red for hot lines, etc.
>
Maybe we can support showing color in a followup patch after the basic
function is ready.
>> For example,
>>
>> Suppose the bf[] has been written with the Percent string yet, next we need,
>>
>> if (--tui) {
>> ui_browser__set_percent_color(...);
>> ui_browser__printf(bf, ...);
>> } else {
>> printf(..., bf);
>> }
>>
>> Is my understanding correct?
>
> The way I am suggesting there will be no if (tui), it will just reuse
> the scnprintf routines that are now used in the TUI code, but will only
> use fprintf/color_fprintf, etc.
>
> The loop iterating over the annotation_lines you just lift from the tui
> code.
>
> And parts that are useful for both and are not yet in __scnprintf form,
> then we need to make it so.
>
OK, I understand, the key point is to avoid using if (tui).
So looks the code will be divided into 2 parts.
Part1: symbol__tui_annotate ->
annotate_browser__refresh/annotate_browser__write
It's current code-path and it's for TUI mode. We will not change it.
Part2:
symbol__stdio2_annotate -> annotation_lines__fprintf ->
annotation_line__fprintf
It's a new code-path and it's for --stdio2 only.
Is my understanding correct? If so, the good thing is we can avoid using
if(tui), while maybe we can't easily reuse common code.
I just think what's the final target we want to reach. For me, I just
wish we had better maintain only one mode (e.g. TUI mode) in future and
for other modes (e.g. stdio), there will be no code work (or no much
code work) for new added features.
If we create a new code-patch for stdio2, looks we have to maintain
stdio2 code-path too when we add new feature to TUI mode.
If we use if(tui), since it's added in TUI code-path, though something
ugly, but we don't need much code work to support stdio for new added
feature.
That's my current thoughts. Correct me if my understanding is wrong.
Thanks
Jin Yao
>>> /* The ab->have_cycles should go to a separate struct, outside
>>> * annotation_browser, and the rest should go to something that just does scnprintf on a buffer
>>> * that then is printed on the TUI or with fprintf */
>>>
>>> if (ab->have_cycles) {
>>> if (al->ipc)
>>> fprintf(fp, "%*.2f ", IPC_WIDTH - 1, al->ipc) > else if (show_title)
>>> ui_browser__printf(browser, "%*s ", IPC_WIDTH - 1, "IPC");
>>>
>>> if (al->cycles)
>>> ui_browser__printf(browser, "%*" PRIu64 " ",
>>> CYCLES_WIDTH - 1, al->cycles);
>>> else if (!show_title)
>>> ui_browser__write_nstring(browser, " ", CYCLES_WIDTH);
>>> else
>>> ui_browser__printf(browser, "%*s ", CYCLES_WIDTH - 1, "Cycle");
>>> }
>>>
>>> SLsmg_write_char(' ');
>>>
>>> /* The scroll bar isn't being used */
>>> if (!browser->navkeypressed)
>>> width += 1;
>>>
>>> if (!*al->line)
>>> fprintf(fp, "\n");
>>> else if (al->offset == -1) {
>>> if (al->line_nr && annotate_browser__opts.show_linenr)
>>> printed = scnprintf(bf, sizeof(bf), "%-*d ",
>>> ab->addr_width + 1, al->line_nr);
>>> else
>>> printed = scnprintf(bf, sizeof(bf), "%*s ",
>>> ab->addr_width, " ");
>>> fprintf(fp, bf);
>>> ui_browser__write_nstring(browser, al->line, width - printed - pcnt_width - cycles_width + 1);
>>> } else {
>>> u64 addr = al->offset;
>>> int color = -1;
>>>
>>> if (!annotate_browser__opts.use_offset)
>>> addr += ab->start;
>>>
>>> if (!annotate_browser__opts.use_offset) {
>>> printed = scnprintf(bf, sizeof(bf), "%" PRIx64 ": ", addr);
>>> } else {
>>> if (bl->jump_sources) {
>>> if (annotate_browser__opts.show_nr_jumps) {
>>> int prev;
>>> printed = scnprintf(bf, sizeof(bf), "%*d ",
>>> ab->jumps_width,
>>> bl->jump_sources);
>>> prev = annotate_browser__set_jumps_percent_color(ab, bl->jump_sources,
>>> current_entry);
>>> ui_browser__write_nstring(browser, bf, printed);
>>> ui_browser__set_color(browser, prev);
>>> }
>>>
>>
>> JUMP is another headache case. For TUI, we need to set color and write jump
>> arrow. While for stdio2, we don't need that. So looks we also need to check
>> if it's in TUI mode.
>
> No, when in --stdio2 case you either show no jump characters, or you
> show them if available, i.e. here are two stdio utilities showing those
> arrows:
>
> [root@...enth ~]# cat a.txt
> ↑ jmp 3f0
> [root@...enth ~]# head a.txt
> ↑ jmp 3f0
> [root@...enth ~]#
>
> You just don't need to print the arrows connecting jumps to its targets,
> because in a function with a lot of jumps, then it can get messy, but
> yeah, that could even be an option, perhaps not the default.
>
>>> printed = scnprintf(bf, sizeof(bf), "%*" PRIx64 ": ",
>>> ab->target_width, addr);
>>> } else {
>>> printed = scnprintf(bf, sizeof(bf), "%*s ",
>>> ab->addr_width, " ");
>>> }
>>> }
>>>
>>> fprintf(fp, bf);
>>>
>>> disasm_line__write(disasm_line(al), browser, bf, sizeof(bf));
>>>
>>> ui_browser__write_nstring(browser, bf, width - pcnt_width - cycles_width - 3 - printed);
>>> }
>>> }
>>>
>>> unsigned int annotation_lines__fprintf(struct list_head *lines, FILE *fp)
>>> {
>>> struct list_head *line;
>>> struct annotation_line *al;
>>>
>>> list_for_each(line, lines) {
>>> struct annotation_line *al = list_entry(line, struct annotation_line, node);
>>> annotation_line__fprintf(al, line);
>>> }
>>>
>>> return row;
>>> }
>>>
>>> Then the main code would use the same code that creates the browser->b.entries
>>> and would pass it to annpotation_lines__fprintf().
>>>
>>
>> Is the main code mentioned here symbol__tui_annotate()?
>>
>> struct annotate_browser browser = {
>> .b = {
>> .refresh = annotate_browser__refresh,
>> .write = annotate_browser__write,
>> ....
>> },
>> };
>>
>> Remove the code line ".write = annotate_browser__write"? Don't need the
>> browser op (write/refresh)? Sorry, I'm not very clear about this idea.
>
> You would have a symbol__stdio2_annotate(), and it would be something
> like:
>
>
> int symbol__stdio2_annotate(FILE *fp)
> {
> struct annotation *notes;
>
> symbol__annotate(sym, map, evsel, sizeof(struct annotatation_line), NULL);
> symbol__calc_percent(sym, evsel);
>
> notes = symbol__annotation(sym);
>
> annotation_lines__fprintf(notes->src->source, fp);
> }
>
> Something like that.
>
>>> i.e. we would disentanble the formatting of strings and auxiliary routines to
>>> obtain the max_percent, i.e. nothing of TUI is needed for --stdio2, just the
>>> formatting of strings.
>
>> Will Arnaldo post your patch? Or do I need to improve my patch and post
>> again?
>
> We're still discussing what is the best way to implement this.
>
>> Thanks
>> Jin Yao
>>
>>>> For example:
>>>> $ perf annotate compute_flag --tui-dump
>>>>
>>>> Percent IPC Cycle
>>>>
>>>> Disassembly of section .text:
>>>>
>>>> 0000000000400640 <compute_flag>:
>>>> compute_flag():
>>>> volatile int count;
>>>> static unsigned int s_randseed;
>>>>
>>>> __attribute__((noinline))
>>>> int compute_flag()
>>>> {
>>>> 23.00 1.16 sub $0x8,%rsp
>>>> int i;
>>>>
>>>> i = rand() % 2;
>>>> 23.06 1.16 1 callq rand@plt
>>>>
>>>> return i;
>>>> 27.01 3.38 mov %eax,%edx
>>>> }
>>>> 3.38 add $0x8,%rsp
>>>> {
>>>> int i;
>>>>
>>>> i = rand() % 2;
>>>>
>>>> return i;
>>>> 3.38 shr $0x1f,%edx
>>>> 3.38 add %edx,%eax
>>>> 3.38 and $0x1,%eax
>>>> 3.38 sub %edx,%eax
>>>> }
>>>> 26.93 3.38 2 retq
>>>>
>>>> The '--stdio' option is still kept now. Maybe in future, we can only
>>>> maintain the TUI routines and drop the lagacy stdio code. But right
>>>> now we'd better keep it until the '--tui-dump' option is good enough.
>>>>
>>>> Jin Yao (4):
>>>> perf browser: Add a new 'dump' flag
>>>> perf browser: bypass ui_init if in tui dump mode
>>>> perf annotate: Process the new switch flag tui_dump
>>>> perf annotate: Enable the '--tui-dump' mode
>>>>
>>>> tools/perf/Documentation/perf-annotate.txt | 3 +++
>>>> tools/perf/builtin-annotate.c | 12 +++++++--
>>>> tools/perf/builtin-c2c.c | 2 +-
>>>> tools/perf/builtin-report.c | 2 +-
>>>> tools/perf/builtin-top.c | 2 +-
>>>> tools/perf/ui/browser.c | 38 +++++++++++++++++++++++----
>>>> tools/perf/ui/browser.h | 1 +
>>>> tools/perf/ui/browsers/annotate.c | 41 +++++++++++++++++++++---------
>>>> tools/perf/ui/browsers/hists.c | 2 +-
>>>> tools/perf/ui/setup.c | 9 +++++--
>>>> tools/perf/ui/ui.h | 2 +-
>>>> tools/perf/util/annotate.h | 6 +++--
>>>> tools/perf/util/hist.h | 11 +++++---
>>>> 13 files changed, 99 insertions(+), 32 deletions(-)
>>>>
>>>> --
>>>> 2.7.4
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