Em Wed, Nov 29, 2017 at 06:04:56PM +0530, Ravi Bangoria escreveu:
>
>
> On 11/24/2017 03:16 PM, Thomas Richter wrote:
> > This patch fixes a bug introduced with commit d9f8dfa9baf9
> > ("perf annotate s390: Implement jump types for perf annotate").
> >
> > Perf annotate displays annotated assembler output by reading
> > output of command objdump and parsing the disassembled lines. For
> > each shown mnemonic this function sequence is executed:
> >
> > disasm_line__new()
> > |
> > +--> disasm_line__init_ins()
> > |
> > +--> ins__find()
> > |
> > +--> arch->associate_instruction_ops()
> >
> > The s390x specific function assigned to function pointer
> > associate_instruction_ops refers to function
> > s390__associate_ins_ops(). This function checks for supported
> > mnemonics and assigns a NULL pointer to unsupported mnemonics.
> > However even the NULL pointer is added to the architecture
> > dependend instruction array.
> >
> > This leads to an extremely large architecture instruction array
> > (due to array resize logic in function arch__grow_instructions()).
> > Depending on the objdump output being parsed the array can end up
> > with several ten-thousand elements.
> >
> > This patch checks if a mnemonic is supported and only adds
> > supported ones into the architecture instruction array. The
> > array does not contain elements with NULL pointers anymore.
> >
> > Before the patch (With some debug printf output):
> > [root@s35lp76 perf]# time ./perf annotate --stdio > /tmp/xxxbb
> >
> > real 8m49.679s
> > user 7m13.008s
> > sys 0m1.649s
> > [root@s35lp76 perf]# fgrep '__ins__find sorted:1 nr_instructions:'
> > /tmp/xxxbb | tail -1
> > __ins__find sorted:1 nr_instructions:87433 ins:0x341583c0
> > [root@s35lp76 perf]#
> >
> > The number of different s390x branch/jump/call/return instructions
> > entered into the array is 87433.
> >
> > After the patch (With some printf debug output:)
> >
> > [root@s35lp76 perf]# time ./perf annotate --stdio > /tmp/xxxaa
> >
> > real 1m24.553s
> > user 0m0.587s
> > sys 0m1.530s
> > [root@s35lp76 perf]# fgrep '__ins__find sorted:1 nr_instructions:'
> > /tmp/xxxaa | tail -1
> > __ins__find sorted:1 nr_instructions:56 ins:0x3f406570
> > [root@s35lp76 perf]#
> >
> > The number of different s390x branch/jump/call/return instructions
> > entered into the array is 56 which is sensible.
>
> Ack-by: Ravi Bangoria <[email protected]>
Thanks, applied.
- Arnaldo
> > Signed-off-by: Thomas Richter <[email protected]>
> > Reviewed-by: Hendrik Brueckner <[email protected]>
> > ---
> > tools/perf/arch/s390/annotate/instructions.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/arch/s390/annotate/instructions.c
> > b/tools/perf/arch/s390/annotate/instructions.c
> > index c9a81673e8aa..89f0b6c00e3f 100644
> > --- a/tools/perf/arch/s390/annotate/instructions.c
> > +++ b/tools/perf/arch/s390/annotate/instructions.c
> > @@ -16,7 +16,8 @@ static struct ins_ops *s390__associate_ins_ops(struct
> > arch *arch, const char *na
> > if (!strcmp(name, "br"))
> > ops = &ret_ops;
> >
> > - arch__associate_ins_ops(arch, name, ops);
> > + if (ops)
> > + arch__associate_ins_ops(arch, name, ops);
> > return ops;
> > }
> >
