Re: [PATCH 6/7] perf tools: Do not need to read symbols for sourceline lookup
From: Adrian Hunter
Date: Wed Dec 04 2013 - 08:52:34 EST
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@xxxxxxxxx>
>> ---
>> 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
>
>
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