On Tue, Jul 15, 2014 at 4:25 PM, Peter Zijlstra <[email protected]> wrote: > On Tue, Jul 15, 2014 at 02:31:40AM +0200, Stephane Eranian wrote: >> @@ -618,6 +619,8 @@ static inline void perf_sample_data_init(struct >> perf_sample_data *data, >> data->weight = 0; >> data->data_src.val = 0; >> data->txn = 0; >> + data->regs_intr.abi = PERF_SAMPLE_REGS_ABI_NONE; >> + data->regs_intr.regs = NULL; >> } > >> +static void perf_sample_regs_intr(struct perf_regs *regs_intr, >> + struct pt_regs *regs) >> +{ >> + regs_intr->regs = regs; >> + regs_intr->abi = perf_reg_abi(current); >> +} > >> @@ -4800,6 +4824,20 @@ void perf_prepare_sample(struct perf_event_header >> *header, >> data->stack_user_size = stack_size; >> header->size += size; >> } >> + >> + if (sample_type & PERF_SAMPLE_REGS_INTR) { >> + /* regs dump ABI info */ >> + int size = sizeof(u64); >> + >> + perf_sample_regs_intr(&data->regs_intr, regs); >> + >> + if (data->regs_intr.regs) { >> + u64 mask = event->attr.sample_regs_intr; >> + size += hweight64(mask) * sizeof(u64); >> + } >> + >> + header->size += size; >> + } > > Given that the prepare_sample hunk sets both regs_intr fields, the > addition to perf_sample_data_init() is entirely superfluous, no?
Yes, looks like it, though having an initialization there prevents any random values for the two fields, in case code tries to check without first testing the sample_format bitmask. So yes, it is redundant but may prevent future errors. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
