From: Leo Yan <leo.yan@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Al Grant <Al.Grant@arm.com>,
"mathieu.poirier@linaro.org" <mathieu.poirier@linaro.org>,
Anshuman Khandual <Anshuman.Khandual@arm.com>,
"coresight@lists.linaro.org" <coresight@lists.linaro.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"mike.leach@linaro.org" <mike.leach@linaro.org>
Subject: Re: [PATCH 3/3] rfc: perf: cs_etm: Detect pid in VMID for kernel running at EL2
Date: Fri, 13 Nov 2020 18:42:48 +0800 [thread overview]
Message-ID: <20201113104248.GA1730@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <7e45fd42-0869-cd4f-1eaf-5d48e4464482@arm.com>
On Fri, Nov 13, 2020 at 09:47:42AM +0000, Suzuki Kuruppassery Poulose wrote:
[...]
> > Rather than heuristic method, I think we can use metadata to store
> > "pid" entry in the function cs_etm_get_metadata(), so that in the
> > record phase, the "pid" is stored into perf data file.
>
> True, that is a good idea. That makes it future proof.
>
> >
> > When decode the trace data, we can retrieve "pid" value from the
> > metadata, and can base on the "pid" value to make decision for using
> > context_id or VMID.
>
> >
> > The metadata can be accessed by referring
> > cs_etm_queue::cs_etm_auxtrace::metadata; but the file
> > util/cs-etm-decoder/cs-etm-decoder.c cannot directly access the
> > metadata structure due to "cs_etm_queue" and "cs_etm_auxtrace" both
> > are defined in util/cs-etm.c. It's better to introduce a helper
> > function in util/cs-etm.c to retrieve "pid" value, like:
> >
> > u64 cs_etm__etmq_get_pid_type(struct cs_etm_queue *etmq);
>
> I am not an expert in that side, how it interacts with the OpenCSD.
> thus left this patch as an RFC.
>
> I appreciate your feedback and thoughts. If you feel like you could
> cleanup and implement this, please feel free to do so. Otherwise, I
> might try it out whenever I have some spare cycles to understand
> this side of the code (and this might be delayed).
You are welcome! Sure, I will try to work out a change and share
back.
Thanks,
Leo
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next prev parent reply other threads:[~2020-11-13 10:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 18:33 [PATCH 0/3] coresight: etm-perf: Fix pid tracing with VHE Suzuki K Poulose
2020-11-10 18:33 ` [PATCH 1/3] coresight: etm-perf: Add support for PID tracing for kernel at EL2 Suzuki K Poulose
2020-11-12 10:27 ` Leo Yan
2020-11-12 12:41 ` Suzuki K Poulose
2020-11-10 18:33 ` [PATCH 2/3] perf: cs_etm: Use pid tracing explicitly instead of contextid Suzuki K Poulose
2020-11-12 10:00 ` Leo Yan
2020-11-12 10:54 ` Suzuki K Poulose
2020-11-12 12:24 ` Leo Yan
2020-11-10 18:33 ` [PATCH 3/3] rfc: perf: cs_etm: Detect pid in VMID for kernel running at EL2 Suzuki K Poulose
2020-11-10 22:57 ` Suzuki K Poulose
2020-11-11 11:03 ` Al Grant
2020-11-11 11:40 ` Suzuki K Poulose
2020-11-13 0:11 ` Leo Yan
2020-11-13 9:47 ` Suzuki K Poulose
2020-11-13 10:42 ` Leo Yan [this message]
2020-11-16 9:46 ` Leo Yan
2020-12-18 10:46 ` Daniel Kiss
[not found] ` <CADDJ8CVqz8Gdkx42H+TjdBOS-Vjk4MAVV7PhAaeBNq9Ejh=usA@mail.gmail.com>
2020-12-23 8:05 ` Leo Yan
2021-01-04 17:33 ` Suzuki K Poulose
2021-01-04 18:06 ` Mathieu Poirier
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