Re: [PATCH v2] perf/hx_arm_ni: Support uncore ARM NI-700 PMU

[Yang Jialong 杨佳龙]

在 2024/2/3 4:11, Robin Murphy 写道:
> On 2024-02-01 2:40 am, Yang Jialong 杨佳龙 wrote:
> > 在 2024/2/1 0:50, Robin Murphy 写道:
> > > On 31/01/2024 7:08 am, JiaLong.Yang wrote:
> > > > This code is based on uncore PMUs arm_smmuv3_pmu and arm-cmn.
> > > > One ni-700 can have many clock domains. Each of them has only one PMU.
> > > > Here one PMU corresponds to one 'struct ni_pmu' instance.
> > > > PMU name will be ni_pmu_N_M, which N means different NI-700s and M 
> > > > means
> > > > different PMU in one NI-700. If only one NI-700 found in NI-700, 
> > > > name will
> > > > be ni_pmu_N.
> > > > Node interface event name will be xxni_N_eventname, such as
> > > > asni_0_rdreq_any. There are many kinds of type of nodes in one clock
> > > > domain. Also means that there are many kinds of that in one PMU. So we
> > > > distinguish them by xxni string. Besides, maybe there are many nodes
> > > > have same type. So we have number N in event name.
> > > > By ni_pmu_0_0/asni_0_rdreq_any/, we can pinpoint accurate bus traffic.
> > > > Example1: perf stat -a -e 
> > > > ni_pmu_0_0/asni_0_rdreq_any/,ni_pmu_0_0/cycles/
> > > > EXample2: perf stat -a -e ni_pmu_0_0/asni,id=0,event=0x0/
> > >
> > > Oh! I've had a driver for this thing sat around for ages waiting to 
> > > find someone with an interest in testing it. Given that from a quick 
> > > skim of this patch I'd also have several concerns with this 
> > > implementation, may I ask that you have a look at my branch and see 
> > > if it works for you?
> >
> > If permission I will test.
>
> Thanks! I see you've also tried to support having the IRQs combined 
> together - does your platform need that right away? That's another thing 
> I've been anticipating but haven't got round to wiring up yet (it's a 
> bit more fiddly than just IRQF_SHARED since perf has some expectations 
> around affinity to event->cpu), but I can have a go at getting it done.

I have not seen the expectations. I will study it.

> > > https://gitlab.arm.com/linux-arm/linux-rm/-/tree/ni-dev?ref_type=heads
> > >
> > > In particular, after the pain of maintaining event aliases in arm-cmn 
> > > I'd really like to get away from doing that again and instead move 
> > > over to jevents this time (especially now that system PMU support is 
> > > a bit more developed there) - I just haven't yet got round to hooking 
> > > up the identifier and writing the JSON files, since it hasn't seemed 
> > > like much of a priority before I know whether the code even works.
> >
> > It's a useful way.
> > Uncore PMU is increasing. Not only CPU event can be writen in jevents.
> > I have not considered it when writing code in a low version.
> >
> > Finally, I have opened a case in arm suppport for linux ni pmu driver.
> > They tell me no driver.
>
> Oh dear, sorry about that - I'd have hoped that a question about a Linux 
> PMU driver might have found its way to our team, even if they weren't 
> aware that NI-700 has already been a specific item on our roadmap for 
> some time :(
>
> Thanks,
> Robin.

I have run the code and thanks to the support of shenghui.qu@xxxxxxxxxxxx.
It's sorry for the late.