Messages in this thread | | | Date | Wed, 24 Jun 2015 09:22:38 +0530 | From | Madhavan Srinivasan <> | Subject | Re: [PATCH v2 6/7]powerpc/powernv: generic nest pmu event functions |
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On Tuesday 23 June 2015 07:19 AM, Sukadev Bhattiprolu wrote: > Madhavan Srinivasan [maddy@linux.vnet.ibm.com] wrote: > | From: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> > | Subject: [PATCH v2 6/7]powerpc/powernv: generic nest pmu event functions > | > | Add generic format attribute and set of generic nest pmu related > | event functions to be used by each nest pmu. Add code to register nest pmus. > | > | Cc: Michael Ellerman <mpe@ellerman.id.au> > | Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > | Cc: Paul Mackerras <paulus@samba.org> > | Cc: Anton Blanchard <anton@samba.org> > | Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> > | Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> > | Cc: Stephane Eranian <eranian@google.com> > | Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> > | --- > | arch/powerpc/perf/nest-pmu.c | 109 +++++++++++++++++++++++++++++++++++++++++++ > | 1 file changed, 109 insertions(+) > | > | diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c > | index 8fad2d9..a662c14 100644 > | --- a/arch/powerpc/perf/nest-pmu.c > | +++ b/arch/powerpc/perf/nest-pmu.c > | @@ -13,6 +13,108 @@ > | static struct perchip_nest_info p8_perchip_nest_info[P8_MAX_CHIP]; > | static struct nest_pmu *per_nest_pmu_arr[P8_MAX_NEST_PMUS]; > | > | +PMU_FORMAT_ATTR(event, "config:0-20"); > | +struct attribute *p8_nest_format_attrs[] = { > | + &format_attr_event.attr, > | + NULL, > | +}; > | + > | +struct attribute_group p8_nest_format_group = { > | + .name = "format", > | + .attrs = p8_nest_format_attrs, > | +}; > > Could this be included in previous/separate patch? That way, > this patch could focus on just registering the nest-pmu.
Yes. Will move it.
> | + > | +static int p8_nest_event_init(struct perf_event *event) > | +{ > | + int chip_id; > | + > | + if (event->attr.type != event->pmu->type) > | + return -ENOENT; > | + > | + /* Sampling not supported yet */ > | + if (event->hw.sample_period) > | + return -EINVAL; > | + > | + /* unsupported modes and filters */ > | + if (event->attr.exclude_user || > | + event->attr.exclude_kernel || > | + event->attr.exclude_hv || > | + event->attr.exclude_idle || > | + event->attr.exclude_host || > | + event->attr.exclude_guest) > | + return -EINVAL; > | + > | + if (event->cpu < 0) > | + return -EINVAL; > | + > | + chip_id = topology_physical_package_id(event->cpu); > | + event->hw.event_base = event->attr.config + > | + p8_perchip_nest_info[chip_id].vbase; > | + > | + return 0; > | +} > | + > | +static void p8_nest_read_counter(struct perf_event *event) > | +{ > | + u64 *addr; > | > > Define as uint64_t so we can eliminate one cast below? Would also > be consistent with p8_nest_perf_event_update(). Yes make sense.
> | > | + u64 data = 0; > | + > | + addr = (u64 *)event->hw.event_base; > | + data = __be64_to_cpu((uint64_t)*addr); > | + local64_set(&event->hw.prev_count, data); > | +} > | + > | +static void p8_nest_perf_event_update(struct perf_event *event) > | +{ > | + u64 counter_prev, counter_new, final_count; > | + uint64_t *addr; > | + > | + addr = (u64 *)event->hw.event_base; > > uint64_t *? My bad. will change it.
> | + counter_prev = local64_read(&event->hw.prev_count); > | + counter_new = __be64_to_cpu((uint64_t)*addr); > > Redundant cast? addr is already uint64_t *?
Nice catch. Will remove it. > | + final_count = counter_new - counter_prev; > | + > | + local64_set(&event->hw.prev_count, counter_new); > | + local64_add(final_count, &event->count); > | +} > | + > | +static void p8_nest_event_start(struct perf_event *event, int flags) > | +{ > > Check PERF_EF_RELOAD before reloading? > > | + event->hw.state = 0; > | + p8_nest_read_counter(event); > | +} > | + > | +static void p8_nest_event_stop(struct perf_event *event, int flags) > | +{ > > Check PERF_EF_UPDATE when stopping? > > | + p8_nest_perf_event_update(event); > | +} > | + > | +static int p8_nest_event_add(struct perf_event *event, int flags) > | +{ > > Check PERF_EF_START flags before starting the counter on an ->add()? Will add the flags.
> | + p8_nest_event_start(event, flags); > | + return 0; > | +} > | + > | +/* > | + * Populate pmu ops in the structure > | + */ > | +static int update_pmu_ops(struct nest_pmu *pmu) > | +{ > | + if (!pmu) > | + return -EINVAL; > | + > | + pmu->pmu.task_ctx_nr = perf_invalid_context; > | + pmu->pmu.event_init = p8_nest_event_init; > | + pmu->pmu.add = p8_nest_event_add; > | + pmu->pmu.del = p8_nest_event_stop; > | + pmu->pmu.start = p8_nest_event_start; > | + pmu->pmu.stop = p8_nest_event_stop; > | + pmu->pmu.read = p8_nest_perf_event_update; > | + pmu->pmu.attr_groups = pmu->attr_groups; > | + > | + return 0; > | +} > | + > | /* > | * Populate event name and string in attribute > | */ > | @@ -106,6 +208,7 @@ static int nest_pmu_create(struct device_node *dev, int pmu_index) > | /* Save the name to register the PMU with it */ > | sprintf(buf, "Nest_%s", (char *)pp->value); > | pmu_ptr->pmu.name = (char *)buf; > | + pmu_ptr->attr_groups[1] = &p8_nest_format_group; > | } > | > | /* Skip these, we dont need it */ > | @@ -179,6 +282,12 @@ static int nest_pmu_create(struct device_node *dev, int pmu_index) > | (struct ppc64_nest_ima_events *)p8_events_arr, > | idx, pmu_ptr); > | > | + update_pmu_ops(pmu_ptr); > | + > | + /* Register the pmu */ > | + perf_pmu_register(&pmu_ptr->pmu, pmu_ptr->pmu.name, -1); > > There is a small chance that perf_pmu_register() can fail. Sure. Will have a check for the return value.
Thanks for review Maddy > | + printk(KERN_INFO "Nest PMU %s Registered\n", pmu_ptr->pmu.name); > | + > | return 0; > | } > | > | -- > | 1.9.1 > |
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