Messages in this thread | | | Date | Thu, 26 May 2022 13:09:47 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 06/13] perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR using IBS_DC_PHYSADDR |
| |
On Thu, May 26, 2022 at 04:29:22PM +0530, Ravi Bangoria wrote: > On 26-May-22 3:26 PM, Peter Zijlstra wrote: > > On Thu, May 26, 2022 at 02:16:28PM +0530, Ravi Bangoria wrote: > >> On 25-May-22 4:51 PM, Peter Zijlstra wrote: > >>> On Wed, May 25, 2022 at 03:09:31PM +0530, Ravi Bangoria wrote: > >>>> IBS_DC_PHYSADDR provides the physical data address for the tagged load/ > >>>> store operation. Populate perf sample physical address using it. > >>>> > >>>> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> > >>>> --- > >>>> arch/x86/events/amd/ibs.c | 26 +++++++++++++++++++++++++- > >>>> 1 file changed, 25 insertions(+), 1 deletion(-) > >>>> > >>>> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c > >>>> index b57736357e25..c719020c0e83 100644 > >>>> --- a/arch/x86/events/amd/ibs.c > >>>> +++ b/arch/x86/events/amd/ibs.c > >>>> @@ -986,13 +986,35 @@ static void perf_ibs_get_data_addr(struct perf_event *event, > >>>> data->addr = ibs_data->regs[ibs_op_msr_idx(MSR_AMD64_IBSDCLINAD)]; > >>>> } > >>>> > >>>> +static void perf_ibs_get_phy_addr(struct perf_event *event, > >>>> + struct perf_ibs_data *ibs_data, > >>>> + struct perf_sample_data *data) > >>>> +{ > >>>> + union perf_mem_data_src *data_src = &data->data_src; > >>>> + u64 op_data3 = ibs_data->regs[ibs_op_msr_idx(MSR_AMD64_IBSOPDATA3)]; > >>>> + u64 phy_addr_valid = op_data3 & IBS_DC_PHY_ADDR_VALID_MASK; > >>>> + > >>>> + if (!(event->attr.sample_type & PERF_SAMPLE_DATA_SRC)) > >>>> + perf_ibs_get_mem_op(op_data3, data); > >>>> + > >>>> + if ((data_src->mem_op != PERF_MEM_OP_LOAD && > >>>> + data_src->mem_op != PERF_MEM_OP_STORE) || > >>>> + !phy_addr_valid) { > >>>> + data->phys_addr = 0x0; > >>>> + return; > >>>> + } > >>>> + > >>>> + data->phys_addr = ibs_data->regs[ibs_op_msr_idx(MSR_AMD64_IBSDCPHYSAD)]; > >>>> +} > >>> > >>> perf_prepare_sample() will unconditionally overwrite data->phys_addr. > >>> There is currently no facility to let the driver set this field. > >> > >> Thanks for pointing it Peter. Would you mind if I add: > > > > I think it's best if you extend/mimic the __PERF_SAMPLE_CALLCHAIN_EARLY > > hack. It's more or less the same problem and then at least the solution > > is consistent. > > I've one more identical optimization in my list. IBS_OP_DATA3[IbsDcPgSz] > can provide PERF_SAMPLE_DATA_PAGE_SIZE. I hope consuming two more bits > for internal purpose is okay.
Yeah, I suppose so.. we'll need to hunt for bits once we run out, but that's how it is...
| |