Re: [PATCH 6/7] perf tools: Do not need to read symbols for source line lookup

[Adrian Hunter <adrian.hunter@intel.com>]

On 03/12/13 22:24, Arnaldo Carvalho de Melo wrote:
> Em Tue, Dec 03, 2013 at 09:23:09AM +0200, Adrian Hunter escreveu:
>> When using libbfd to lookup source filename and line number,
>> libbfd does not need the symbol table.  Removing the symbol
>> table reading, doubles the speed of 'perf script' with the
>> 'srcline' option.
> 
> [root@zoo ~]# gdb perf
> run report -s srcline
> 
> b00000m

I wasn't able to reproduce this but I noticed the line numbers
were not found for kernel modules with this patch - so it seems
some binaries need the symbol information and some don't.

So please disregard this patch, sorry for your trouble.

> 
> bt
> #0  0x000000000050ac60 in read_unsigned_leb128 ()
> #1  0x00000000005189f7 in find_abstract_instance_name.isra.20 ()
> #2  0x00000000005190e1 in scan_unit_for_symbols ()
> #3  0x0000000000519a69 in comp_unit_find_nearest_line ()
> #4  0x000000000051a6ff in find_line.part.26 ()
> #5  0x0000000000531063 in _bfd_elf_find_nearest_line_discriminator ()
> #6  0x000000000053117b in _bfd_elf_find_nearest_line ()
> #7  0x00000000004bf22d in find_address_in_section (abfd=0x39de5f0, section=0x3a32c38, data=0x3901950) at util/srcline.c:51
> #8  0x000000000050ccdc in bfd_map_over_sections ()
> #9  0x00000000004bf48b in addr2line (dso_name=0x39fb830 "/lib/modules/3.13.0-rc1+/kernel/drivers/gpu/drm/drm.ko", addr=20832, 
>     file=0x7fffffffcc00, line=0x7fffffffcbfc, dso=0x90f9e0) at util/srcline.c:116
> #10 0x00000000004bf608 in get_srcline (dso=0x90f9e0, addr=20832) at util/srcline.c:217
> #11 0x00000000004b00fe in sort__srcline_cmp (left=0x1dc76f0, right=0x7fffffffcd70) at util/sort.c:268
> #12 0x00000000004b3942 in hist_entry__cmp (left=0x1dc76f0, right=0x7fffffffcd70) at util/hist.c:450
> #13 0x00000000004b35f4 in add_hist_entry (hists=0x90f278, entry=0x7fffffffcd70, al=0x7fffffffcf90, period=399301, weight=0)
>     at util/hist.c:367
> #14 0x00000000004b38d8 in __hists__add_entry (hists=0x90f278, al=0x7fffffffcf90, sym_parent=0x0, bi=0x0, mi=0x0, period=399301, 
>     weight=0, transaction=0) at util/hist.c:440
> #15 0x000000000042c9da in perf_evsel__add_hist_entry (tool=0x7fffffffd510, evsel=0x90f1d0, al=0x7fffffffcf90, sample=0x7fffffffd140, 
>     machine=0x90e6b8) at builtin-report.c:274
> #16 0x000000000042cd4f in process_sample_event (tool=0x7fffffffd510, event=0x7ffff17aea30, sample=0x7fffffffd140, evsel=0x90f1d0, 
>     machine=0x90e6b8) at builtin-report.c:347
> #17 0x000000000049df43 in perf_session__deliver_sample (session=0x90e5e0, tool=0x7fffffffd510, event=0x7ffff17aea30, 
>     sample=0x7fffffffd140, evsel=0x90f1d0, machine=0x90e6b8) at util/session.c:930
> #18 0x000000000049e107 in perf_session_deliver_event (session=0x90e5e0, event=0x7ffff17aea30, sample=0x7fffffffd140, 
>     tool=0x7fffffffd510, file_offset=821808) at util/session.c:984
> #19 0x000000000049cfb4 in flush_sample_queue (s=0x90e5e0, tool=0x7fffffffd510) at util/session.c:526
> #20 0x000000000049ef53 in __perf_session__process_events (session=0x90e5e0, data_offset=216, data_size=832400, file_size=832616, 
>     tool=0x7fffffffd510) at util/session.c:1371
> #21 0x000000000049f02e in perf_session__process_events (session=0x90e5e0, tool=0x7fffffffd510) at util/session.c:1389
> #22 0x000000000042d605 in __cmd_report (rep=0x7fffffffd510) at builtin-report.c:527
> ---Type <return> to continue, or q <return> to quit---
> 
> Applied all except this one and the other one David commented on,
> waiting for that discussion to reach some conclusion.
> 
> But with the ones applied 'perf report -s srcline' is _much_ faster,
> thanks!
> 
> - Arnaldo
>  
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>>  tools/perf/util/srcline.c | 53 +----------------------------------------------
>>  1 file changed, 1 insertion(+), 52 deletions(-)
>>
>> diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
>> index 93795f9..e09c9e0 100644
>> --- a/tools/perf/util/srcline.c
>> +++ b/tools/perf/util/srcline.c
>> @@ -29,54 +29,6 @@ struct a2l_data {
>>  	asymbol 	**syms;
>>  };
>>  
>> -static int bfd_error(const char *string)
>> -{
>> -	const char *errmsg;
>> -
>> -	errmsg = bfd_errmsg(bfd_get_error());
>> -	fflush(stdout);
>> -
>> -	if (string)
>> -		pr_debug("%s: %s\n", string, errmsg);
>> -	else
>> -		pr_debug("%s\n", errmsg);
>> -
>> -	return -1;
>> -}
>> -
>> -static int slurp_symtab(bfd *abfd, struct a2l_data *a2l)
>> -{
>> -	long storage;
>> -	long symcount;
>> -	asymbol **syms;
>> -	bfd_boolean dynamic = FALSE;
>> -
>> -	if ((bfd_get_file_flags(abfd) & HAS_SYMS) == 0)
>> -		return bfd_error(bfd_get_filename(abfd));
>> -
>> -	storage = bfd_get_symtab_upper_bound(abfd);
>> -	if (storage == 0L) {
>> -		storage = bfd_get_dynamic_symtab_upper_bound(abfd);
>> -		dynamic = TRUE;
>> -	}
>> -	if (storage < 0L)
>> -		return bfd_error(bfd_get_filename(abfd));
>> -
>> -	syms = malloc(storage);
>> -	if (dynamic)
>> -		symcount = bfd_canonicalize_dynamic_symtab(abfd, syms);
>> -	else
>> -		symcount = bfd_canonicalize_symtab(abfd, syms);
>> -
>> -	if (symcount < 0) {
>> -		free(syms);
>> -		return bfd_error(bfd_get_filename(abfd));
>> -	}
>> -
>> -	a2l->syms = syms;
>> -	return 0;
>> -}
>> -
>>  static void find_address_in_section(bfd *abfd, asection *section, void *data)
>>  {
>>  	bfd_vma pc, vma;
>> @@ -96,7 +48,7 @@ static void find_address_in_section(bfd *abfd, asection *section, void *data)
>>  	if (pc < vma || pc >= vma + size)
>>  		return;
>>  
>> -	a2l->found = bfd_find_nearest_line(abfd, section, a2l->syms, pc - vma,
>> +	a2l->found = bfd_find_nearest_line(abfd, section, NULL, pc - vma,
>>  					   &a2l->filename, &a2l->funcname,
>>  					   &a2l->line);
>>  }
>> @@ -122,9 +74,6 @@ static struct a2l_data *addr2line_init(const char *path)
>>  	if (a2l->input == NULL)
>>  		goto out;
>>  
>> -	if (slurp_symtab(abfd, a2l))
>> -		goto out;
>> -
>>  	return a2l;
>>  
>>  out:
>> -- 
>> 1.7.11.7
> 
>